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Vincent Motorcycle Engines - Technical Information

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Andy Hopkin's Die Cast Rapide Engine

Comet Timing Gear Group.  Revised 10/7/07 incorporating your comments. (Gwilym Davies) Higher resolution (revised) copy for your parts manual.

I hesitate to Constantly remind you... but many of the following "practices" are highly controversial...  Proceed at Your Own Risk.

Engine Condition : by  Max Lambky 12/5/2011     At one time or another most Vincent owners find it necessary to assess the condition of their motorcycles, the engine being the primary part of the inspection. The reasons for engine inspection are many. If the inspection is made prior to the purchase, it could be a major issue as to the final agreed upon purchase price. Another reason would be to ascertain the degree of overhaul required to bring the engine back to standard, and in the case of a restoration, to ascertain the engine's condition, as it would be a variable in the cost of a total restoration.

A pretty good assessment as to engine condition can be obtained without a complete tear down and the use of a micrometer. Using your five senses can result in a fairly accurate condition appraisal. If the engine is a running unit, a lot can be deduced by simply listening to the sounds omitted when running. Static sound tests and riding sound tests are easy enough to initiate. Crankshaft big ends and piston slap can usually be detected by a discerning ear during hard acceleration and deceleration of engine parts. Bluish smoke from the exhaust pipe during hard acceleration is most likely caused by worn rings or excessively worn valve guides, or it may be something as simple as missing overhead oiling wire restrictors. Transmission parts and their wear can also sometimes be determined by hard acceleration and deceleration in each gear. A whining noise, jumping out of gear, or poor shifting characteristics, are all symptoms of wear in the condition of the transmission. The engine running in a static mode, can easily be checked by using a common shop tool, the screwdriver. Place the working end of the screwdriver on various locations of the motor, by holding the screwdriver to your ear you can easily detect metallic noise. Engine parts that have worn and excessive clearance will become apparent. Head, cylinder muff, timing cover, primary cover, and engine cases should be checked. Better yet than the screwdriver, a physician's stethoscope would be a good choice.

A thorough visual inspection of engine and parts should be conducted as well. Married parts, such as crankcase to crankcase, primary cover to crankcase, timing cover to crankcase, should be checked for oil leakage. Excessive leakage can sometimes be caused by warped or poor mating surfaces. A visual inspection of the oil filter and the drained oil, of both engine and transmission, are very important. Metallic particles can tell you a lot as to engine condition. The oil filter after a period of use, will always have some metallic particles, this is usually of little concern. Cam timing gears and other moving parts, are continually giving up minute metallic particles in their wear. With the exhaust pipes removed, the exhaust ports and their carbon deposits can also give you an indication as to engine condition, also while the exhaust pipes are removed, check the condition of the female threads of the cylinder heads. An oil saturated carbon deposit on the port is an indication of leaking valve guides or worn piston rings. Don't limit your visual inspection to mechanical only. A thorough cosmetic inspection is useful as well, in determining restoration expense. Engine finish on Shadows and covers on D's, as well as broken fins, can add to the restoration cost more than what one would think. Rounded hex head nuts and bolts can also be expensive.

Feel and touch is also used to determine the condition of some engine parts. One common check is performed by removing the rocker arm caps, turning the engine over to where the cam of the rocker to be checked is on it's heel. Grip the rocker in the area of the push rod adjusting screw with a pair of pliers. Try moving the rocker athortship of the bike. If movement is detected it's more than likely that the rocker bushing bore in the head, and the bushing itself, has given up it's interference fit, and is loose in it's bore. This isn't good, but is pretty common in engines that have several miles on them. Another feel check is one that determines the amount of wear of the cam timing gears, idler gears, breather gear, and magneto drive gear. This is done by checking for excessive back lash. Remove rocker covers and back off all rocker adjusting screws. Remove cam cover inspection plate. Rotate the fiber or nylon magneto drive gear clockwise then counter clockwise. Too much rotation indicates one, or more, or all, gear meshing teeth being excessively worn. Repair can be as simple as replacing crankshaft half time pinion to oversize. Often early aluminum or brass gears will require replacement. The same goes for the fiber mag drive gear. All of these gears are prone to wear.

The magneto automatic advance is checked as to it's condition in the following manner:

With the magneto point cover removed, turn the magneto, expanding the advance fly weights to their maximum. The springs to the fly weights should be adequate in strength to return the magneto to it's original position without a sluggish movement. If you get a quick return, this will give you a pretty good indication as to the condition of the weight's pivot points and it's mechanism, plus magneto bearing condition and crush fit. Magneto spark should be checked as well. Remove spark plugs. Take an old set of sparkplugs that are functional and of the same heat range and kind, open up the ground electrode to approximately 3/16" near the same as possible. Tape over gapped sparkplugs hex nut to ground with duct tape. With the engine out of gear, kick it over. Both sparkplugs on the twin should show a blue to a blue-white spark at the gap. A yellowish, or no spark, indicates that a rework of the magneto will be necessary.

A routine and most common practice in determining engine condition is to perform a compression test, or leak down of the cylinders to determine the ring seal and the valve and valve seat conditions. To do either of these tests with confidence you must first understand that compression ratio differs from compression pressure. For example on a twin, if you increased the compression ratio from a 7 to 1 piston to an 8 to 1 piston, there would be no difference caused by the change when performing a leak down. The leak down method is the best of the two as it gives you the condition of the sealing capability of the valve and the sealing capability of the ring. The problem with determining engine condition with the use of a compression gauge is that there is an 'unknown'. The unknown being the cam timing, only in the case of the twin, from cylinder to cylinder. Compression of the cylinder during tests starts at the timing of the closure of the intake valve. Cam timing, such as it is on most Vincent twins, leads to false readings. A reading of say, 155 lbs. pressure on one of the cylinders, and 160 lbs. on another cylinder doesn't necessarily mean the latter is the better of the two cylinders in their sealing ability. The Vincent owner who is dealing with an unfamiliar engine is pretty much left with the leak down method as his only recourse to achieve a true condition check of the cylinders. Compression checks are made valid only when valve timing, cam to cam, is proven to be 'spot on' by proper degreeing of the cams.

It's a good idea for the new owner of a Vincent who isn't familiar with the Beast, to employ a person of proven capability who's been around Vincents for awhile to test ride and give his input on the condition of the bike's engine as well.

Discussion of Engine Balancing: When I was, I think, 14 years old, I bought a JD Harley Davidson motor from my motorcycle mentor Burt McNew. Spent 10 dollars for the froze up JD, but it did come with a manual. Strangely enough I still remember the pages that had to do with balancing the JD's crankshaft. It explained two parallel bars made level with a machinists level. It went on to say with the crankshaft assembled without the rod assemblies make a bob weight that can be affixed to the big end crank pin. The weight of the bob weight should be equal to the weight of all the rods, roller bearings, wrist pins, sir clips, rings, and one piston. Placed the trued crankshaft on the parallel bars, drill holes as necessary in the fly-wheels to achieve near static stability in any position of the rotated crankshaft.I would guess as the pistons were quite heavy that you would be working with a possible 60% balance factor.

Balancing of engines is pretty much a black art. Percent factors of balance are only used in V-twin engines and parallel twins where the crankshaft is not a hundred degree crankshaft. These are the only engines that require a bob weight to balance the crankshafts. Opposed cylinder engines, multi-cylinder V engines, and inline engines with 2 or more cylinders all do not require a bob weight to be manufactured and used. The crankshafts are so designed that counterweights are equal.

There are 2 forces in balancing an engine that are corrected. The first being the kinetic energy when spun, which is a direct up and down, side to side straight force. The next is the dynamic balance of the crankshaft, which is the movement forces at the ends of the crankshaft. For practical purposes, a Harley Davidson V-twin with the split-rod has its rod and piston mass on a straight plane, which drastically reduces the tendency of dynamic imbalance. In other words, it's a waste of time to pay a lot of attention to blueprinting pistons or rods. e.g. making the weigh the same. Do to the fact of the mass on a single plane. Now, the Vincent can benefit slightly by blueprinting the rods and pistons, e.g. making them weigh the same as the rods are side by side and the weights are not on a single plane in relation to the linear length of the crankshaft. Equal balance of the pistons and rods on separate planes alleviates some of the dynamic balance factor.

You wouldn't think that a flywheel, being balanced, would have any dynamic balance input. It's pretty unbelievable, but they do. A flywheel on an automobile, one half inch thick requires dynamic balance often by drilling on both sides of the flywheel. Both sides can correct the dynamic balance, but cannot correct the kinetic balance. The kinetic balance can be corrected by drilling on one side, but it's best to drill on both sides an equal amount.

A dynamic balancing machine has adjustable spring pensioners to counteract large masses to be balanced. Both knife rollers and flat ball bearing rollers are used depending on the length of the part to be balanced. For instance, a straight eight Buick crankshaft, remember, requiring no bob weights, would utilize ball bearing rollers on it's end main bearings. This would give the most sensitivity to the machine as to it's dynamic balance. Both kinetic and dynamic balance factors are corrected usually simultaneously. V6 engines are the most cantankerous of all to balance. Don't ask me why, it's too confusing for this wrench. Now that I probably have everyone confused, I know I am. I'm going to retire.     Max Lambky  10/24/2011

Blueprinting a Vincent Connecting Rod
Properly blueprinting a pair of Vincent connecting rods is easier said than done, and takes more time than the average engine builder would care to invest.
If you're privy to a rod stash, meaning more than two, the first step is to select near likeness in their shape. Before you start to blueprint the rods, save yourself a lot of time and grief by magnafluxing to determine whether they're worthy of a blueprint. Forgings varied, not due to forging procedures using the same forming die. Variations were caused by various forming dies. I believe as many as four die manufactures were utilized in the manufacture of dies used by the Vincent Works. If you don't have a stash of rods you have to make do with what you have. The initial steps in blueprinting the rod is it's disassembly. Of course I'm referring to used rods, not new rods. Push the big end bearing races from the big end rod bore, and push the wrist pin bushings from their bore. Clean the two rods thoroughly, especially the big end and the little end bores. Discard the bushings and the big end outer races. In a proper blueprint these items are made new. With a bore gauge, check the roundness of the big end bearing bore of the rod as well as the bushing end, or little end. Check the diameters of the two bores as well. These dimensions are important for proper crush of the new big end bearing race. The little end bushing bore is not so important as oversize bushings, can readily be made, and aren't that expensive. If the big ends are found out of round, it's best to discard the rod and find yourself one that's round. Some fellows hone the rod round, hard chrome the race, and regrind to achieve proper interference fit. I'd only recommend this for engines that are to be utilized in street use, not for racing. The desired interference fit between the outer big end race and the big end of the rod is .0015 any more crush than this will cause egg shaping of the bearing. The cylindrical bore of the rod isn't equal in strength. The portion where the rod I beam attaches to the big end bearing boss will not distort. Approximately 210o of the big end bore is subject to distortion due to lesser strength. Bushing interference fit of the little end should be .001. This is enough interference fit to prevent any turning of the bushing in it's bore, even if it were to be subjected to racing rpms. Any less than .001 interference fit can cause the bushing to turn in it's bore, causing oil starvation to the wrist pin due to misaligned oil holes bushing to rod.
Before installing the big end race and the small end bushing, the rod must be checked for straightness, both X and Y axis. For this to be done accurately it's best to take the rods to an automotive engine building facility that would have a rod aligning tool. If the rods are the same length, i.e., the exact center of the big end bore and the small end bore, another method is sometimes used. Two pins approximately six inches long, one being turned on the lathe to achieve a slide fit in the big end bore, the other being a slide fit in the little end bore, can do the job quite nicely. Simply achieve a slide fit through both rods with the two sized pins, where there is no hint of interference or binding. If you can do this, the rod is straight, and the X and Y are accurate.
Next, the rods should be checked for equal length. If the two small end bores have the same diameter, and the big end bores are the same diameter, you can measure the rod's length with the use of a caliper. If the rod's measure the same length, go to the next step. Rods will vary in length only a max of, say, .005. If you take the longer of the rods and use the six inch steel pin used for checking alignment, placing it in a press, holding the pin with V blocks, and use an old piston, with wrist pin holes bored to align pin diameters, you can press the rod, using about seven tons pressure, to reduce it's length to match the other rod. No heat required. Work up on steps, one ton, two ton, three ton, checking length of rod between each press.
With all of this satisfied, the two rods now can be made equal in weight. If the two rods are within 20 grams of each other, remove 10 grams from the heaviest of the two in the area of the outboard sides of the I beam. Next, place the big end on a gram scale as near center to the scale plate as possible. Using a hangman's tree, suspend the little end with a string. Weigh the big end, do the same with rod number two. Remove weight as necessary from the heaviest of the two in the area of either side of the strong back web. Retain as much of the strong back web as possible. This is the main strength feature of the Vincent connecting rod, which contributes to nearly 90% of the rigidity, retaining roundness at high rpm.
Reverse the process and weigh the little end of the connecting rods. Determine the heaviest, and remove material over a reasonable area from the convex portion of the I beam, 1" below the wrist pin boss of the rod. Remove equal amounts from both sides to obtain equal weight. What you've accomplished by approaching weight removal in this manner is equalization of the reciprocating weights and the rotating weights of the two con rods. A light polish to remove any sanding scores over all areas of both rods is the next step.
For racing engines drill an additional oil hole in the center of the convex and at the radius of the little end boss 1/16" in diameter. With a quarter inch counter sink, champher the outer end of the drilled hole.
Mask off the inner bores of both the big end bore and the little end bore of both rods. Find a source that has the ability to shot peen. Shot peen both rods to a matt finish over all surfaces. Now you're ready to insert the new outer race of the big end bearing into the now blueprinted rod. Ensure that the rod in the bearing has a .0015 interference fit, as mentioned before. Bearing, sleeve, lube of your choice, should be used to aid in a slight smooth friction push with a press, negating any chance of gaulding. Use same procedure on little end bushings. If the little end bushings have not been predrilled, drill bushings slightly undersized of rod oil holes. This requires the use of numbered bits. Reduce the hole to be drilled by three numbers. After drilling, deburr the inner portion of the drilled holes. When drilling, adjust drill stop so as not to damage the adjacent wall of the bushing.
Now you can fit the wrist pin to it's bushing bore and the big end cage roller clearance. The little end requires reaming to obtain a slide fit. This fit is the same whether used for racing or high speed touring. Fitting the big end roller clearance is best done by a professional with the proper honing equipment. Clearance for street use is between .001 and .0015. For racing .002 to .0025. Some would say this is too much clearance, however, I've found that the greater clearance reduces roller skating when a blower is used, or with high loads of nitro methane.
A blue printed rod helps a tad to reduce vibration, increases the strength of a standard rod by maybe 15%. The blueprinting procedure, when done properly, pretty much parallels the Vibrac rod. Neither of which is up to a Corrello rod's specification, or their ability to withstand the abuse of racing as well as the Corrello. For racing, one would use a standard rod or a Vibrac rod only to retain originality. The choice is yours.  Max Lambky   10/9/2011

Replacing the Upper Pushrod Seal:  You'll have a 75% chance of sealing the leak without pulling the head by replacing the seal between the pushrod tube flange and the cylinder head machined flat. Here are a few pointers to make the job go smoothly. 1. Before loosening the gland nut, ensure there is at least one thread visible. You are checking the crushed two fiber washer thicknesses. As you are only replacing one gasket instead of two, you must determine that there are enough threads on the gland nut to provide adequate crush on the new seal before the gland nut runs out of threads for tightening. 2. Next remove the rocker cover. Turn the engine over to where the cam follower is on the cam heel. Remove the rocker adjuster, then the push rod. Loosen the gland nut totally out of it's threads. You can now slide the push tube cover in it's crankcase bore to the point to where it stops against the cam lifter. This will give you the most distance between the push tube and the cylinder head for the upper gasket removal. 3. You can now with a 90o scribe, remove the upper seal. The one's I have have a handle on them for grip. If you don't have one of these types of scribes, you can take a normal type scribe, bend the end (usually takes heat) to where you have a 90o, 1" long sharp end. Then clamp a small pair of vise grips onto the opposite end of the scribe. This will give you a tool with which you can remove a sometimes cantankerous upper seal in it's totality. 4. When you reassemble the parts, separate the the gland nut from the seal. Lightly coat the seal without disturbing it with permatex #2, the non hardening stuff. The reason for not disturbing the seal is that often they have hardened and become quite brittle. Coat the threads of the gland as well. 5. I've heard that some have renewed both seals by soaking the seal between the packing gland nut and the lower portion of the tube flange in hot water. Then they make a herring bone cut, splitting the seal so it can be installed. I've never tried this, but it could possibly work.  Max Lambly  5/1/2011

Big End Flush It's not uncommon to hear of a big end failure when a machine is started up and run after having been sitting for years or even decades. Sometimes - maybe most of the time - it doesn't happen right away; the mechanism perhaps being that the tiny oil path "down there" through the flywheels and rollers gets heated up thanks to gummed up oil and goo that has semi-solidified over time.  Even with modern detergent oil, the stuff is not pushed out, so only minimal oil feed occurs, if at all. Even if the damage at first is minute, once things start going bad it snowballs until the roller and races get all angry and eventually grind to a halt. So, a happy startup suddenly ends after a few hundred miles or
maybe even a thousand. We might hear of more of this happening these days if all new Vincent owners of barn finds went riding. But, as we often see, a new owner gets the bike running, feels great about it, then mostly lets it sit, only
occasionally going for a short ride, never really knowing they are sitting on a time bomb.

With the oil drained, the quill removed and the sump drain plug out and the bike on the rear stand, shoot some solvent into the quill. With the bike in 4th gear, rotate the engine (spark plugs out). Squirt, squirt, squirt, at different
positions of flywheel movement. After lots of squirting give it a few (light) bursts of air for encouragement. Squirt some more  and let it sit overnight, allowing the solvent sequestered there do its thing. At this stage you might
want to use WD40 or something similar as it will not dry up as easily as the meaner stuff. Next day squirt some more solvent and do a final air burst with the bike on its left side stand. When you are confident there is flow, get all
the solvent out of the sump and then with some very lightweight oil get some oil flow through there. When you are confident that is done, introduce engine oil.  Bev Bowen  4/18/2011

Starting an old Vincent engine:  There is no substitute for using bike often... starting and warming through for a longish run, change oil and filter at regular mileage, thin in winter thicker in summer, but they do run okay on a 30 wt oil,  the big ends get clogged up with crap in that oil groove and nothing will move it only to take apart and clean it... gets so hard no amount of WD40 or gunpowder will shift the stuff.   In my mind an older motor should not be started without dismantling and given a good thorough cleaning.  Mike White 4/18/2011

When you switch from a non detergent oil (ND) to a detergent oil, built up sludge becomes loosened and goes back into suspension in the oil due to detergent action on it. In a high enough concentration in the oil it is very detrimental to wear especially in high pressure plain bearings.  All engine oils will build up sludge in suspension over time both from combustion product contamination as well as breakdown of the oil itself (especially in the case of plain bearings). Older engines using non detergent oil relied on a settling period, either in the sump (autos) or the oil tank (motorcycles) to allow the suspended matter in the oil to settle out as a sludge. These engines use primitive oil filtration, usually a only fine metal gauze to trap out large foreign particles.  In later engines where detergent oil is used the contamination products are deliberately maintained in suspension by the detergent but are continuously removed by a much more sophisticated and finer high surface area filter in the form of a paper cartridge or element. This is one reason why its necessary to regularly change oil filters in modern engines.  The post war Vincent is an interesting hybrid in a way. It does have a relatively sophisticated filter system for it's time compared to say a fifties Triumph or BSA in that it has a fine wool element incorporated in addition to gauze which, whilst not as efficient as a modern filter, does trap some suspended matter. It also has a long residence oil tank for sludge deposit.  However if you replace the original element with the newer much finer paper cartridge element that's available it becomes in essence no different to a modern engine. You have the best of both worlds, a highly efficient filter and a large sludge settling tank. You can happily operate it with either type of oil. Even if you you inadvertently add detergent oil to what has been an ND engine to date any sludge loosened up should be effectively caught by the paper cartridge.  In an older looser engine my thought would be to replace the element fairly regularly either way as it's not particularly large compared to that of say a late Norton or Triumph (using essentially an auto filter) and I would assume it to have a fairly modest capacity.   Tim Holcroft  4/18/2011  

Oiling Your Vin:  by Max Lambky  3/30/11

There are four separate and distinct methods to which moving parts are subjected in regard to their lubrication.  They are drip, pressure, splash, and mist.  The drip happens when the oil return pump sporadically returns oil to the oil tank through the oil return line.  The line is open to the oil tank, thereby negating any pressure development from a metering orifice, or closed end.  There is no pressure in the return line, only sporadic volume head pressure, which is quite minimal, as the only volume head pressure is created by the amount of oil that is in the return line, which is the mere amount of oil contained in a quarter inch inside diameter line, sixteen inches in length.  The amount of oil that's allowed to drip through the overhead oiling system at 140o F. temperature, is only approximately 12 to 16 drips per minute with the restricting wire removed.  The restricting wire reduces the drip flow to 8 to 12 drips per minute.  There's no difference in the amount of drips from 50 wt. oil to 20/50 wt. oil, when the oils reach 140o F..  This is the only portion of the lubricating system on a Vincent that's not increased in proportion to engine rpm.  The engine at idle receives the same amount of oil through the overhead rocker oiling orifices, as it does at 6500 rpm top revs. 

Other parts of the engine oiling system controlled by drip orifices are the cam timing idler gear spindle, and the oil pump worm gear.  Here again, these are zero pressure lubricated. Don't confuse the parts that are oiled by splash and mist, with the parts being oiled by drip.  Drip can only be created when the mist and splash finds it's way to the inner surfaces of the crankcase's primary case, transmission case, and push rods.  When the wetted surfaces are such that the amount of oil is saturated to the extent that gravity takes over and causes the oil to run, much like when shooting paint to excess, drip is created.  Some surfaces extend without interruption to the sump, and no drip occurs.      

Splash lubrication is accomplished when a moving part passes through a reservoir of oil, or a solid stream of oil is pressure fed to a moving part.  The transmission and primary case, both containing an oil reservoir and moving parts, are examples of splash lubrication.  No pressure involved.  Machined canal passages are utilized to facilitate the lubrication of the bushings and shafting in the Vincent's use of the splash system.  Bushing canals are sometimes enhanced in their lubrication ability by spiral machining much better than with a straight broached oil canal. 

Three other engine parts are being lubricated by splash, the cam timing gears teeth, the non thrust side of the cylinder walls, and the little end of the con rod.

Moving parts that are oiled by pressure are the thrust sides of the pistons, the crankshaft's big end, and the two camshaft spindles. (or should I say the cam bushings and cam lobes?)  The oil pressure to lubricate these parts is created by the pressure side of the oil pump.  The pump being a plunger, and the cylinder feed ports' opening and closing by the piston's passing over them, causes an inconsistant sporadic pressure variance.  As the pressure oiling system feeds a manifold which contains five outlets, the amount of oil to each outlet isn't equal in volume.  The oil to the cam bushings is less than the oil to the thrust side of the pistons.  The oil to the thrust side of the pistons, in volume, is less than the big end of the crankshaft, due to the fact that the crankshaft acts as a centrifuge, increasing pressure and volume at the big end oil holes.  The oil volume is actually increased by a suction action on the oil manifold, caused by the centrifuge of the crankshaft.  As crankshaft rpm increases, the volume of oil to the crankshaft increases as well.  The supply to the manifold is increased with engine rpm.  The volume of oil to the five manifold outlets isn't proportional and constant through the rpm range. 

All main bearings except one are oiled by drip or mist.  All transmission gears and bushings are oiled by splash.  All clutch bushings, primary chain, sprockets, and outer ball bearing main, are oiled by splash. 

The windage of the moving parts, mainly the crankshaft and the cam gears, cause oil mist.  Little, if any, mist is caused by rocker arm movement, or cam lifter movement.  The mist permeates throughout the entire inside of the crankcases, cylinder head, and oil cavities.  This mist covers all parts, and some are actually lubricated from the mist.  The timed breather is mist lubricated.  This is why the timed breather requires more clearance than would normally be necessary, if it were pressure lubricated.  The cam lobes receive very little additional lubrication from the inner sidewalls of the push rod tube.  This oil is no more than a drip caused by gravity, it leaving the end of the tube, and falling on the cam lobe, which is spinning, actually repels the drip.  Try to oil a fan blade in motion, and you'll see the problem with trying to lubricate by drip.  The additional oiling to the cam lobes and lifters, the first being the pressure lube of the parts, and the second being due to the phenomena of wicking.  The oil mist adheres to the push rod, and when saturated to a point of a gravity induced run, the oil wicks itself to the end of the cam lifter.  The oil wicks through the hole in the end of the lifter, and is then guided by a groove on the lifter work side, and wicks it's way to the cam, where it lubricates the two moving parts.  The pivots on the cam followers are lubricated by mist.  All rocker pressure points are lubricated primarily by mist.  The rocker arm push rod end is lubricated by mist, the lower push rod end is lubricated by gravity wicking.    

The grooves in the crankshaft's feed quill assist in keeping the oil going the right direction.  This action is employed as well with the groove spacer between the ball and roller main bearings on the drive side.  Oil mist increases as engine parts wear.  Older engines with more hours on them will mist more than a fresh engine.  Usually oil pressure reduces as an engine wears.  Splash increases when viscosity decreases.  Low viscosity oil produces more mist.  The oil pump and it's cam drive pin are lubricated by pressure.

Oil Sumping:    Oil by gravity is fed to the oil pump first through a filter screen, then through a check valve, from there through a line partially rubber and partially tubing.  A banjo bolt connects the oil supply line to the engine.  Oil then flows through a short port in the engine to the oil pump intake port.  The oil pump consists of a small engine supply pump on one end, and a larger engine return pump on the other end. 

How does oil get to the sump from the supply pump port?  Think of the supply pump in it's brass bore to the likeness of a leaking petcock valve, i.e., leaking between the clearance between the pump and it's housing.  From there, there are two paths to the sump.  One being between the pump and housing clearance to the opening relief of the oil pump housing, required for worm gear engagement to pump gear teeth.  Next is the oil passage from the pump to the oil filter cavity, then to the timing cover oil passages through the timing cover banjo bolt.  Oil is then transferred by gravity through the built in cast passageways in the timing cover, to the two cam spindles, which then can find it's way through the clearance between cam bushings and cam spindles.  Some oil is returned to the sump through drilled oil passages in the cam lobes, and some oil enters the sump through both ends of the cam.  Other oil returns to the sump from the oil passage in the timing cover to the crankshaft quill ports to the crankshaft main shaft center drilled oil port.  Oil then, depending on crankshaft position, either returns oil to the sump past the labyrinth of the oil quill to the end of the crankshaft, where it enters the timing chest and then to the sump.  If the crankshaft's big end is at it's bottom, nearest the bottom of the crankcase, oil flows through the main shaft oil passage, then to the crankshaft's drilled oil passage, then to the two big end's oil passages, then through the bearing cages, and into the sump, which is the path of least resistance over the quill's resistance. 

Actually, the most common return passage is from the oil intake port on the pump past the outer circumference of the brass housing clearance to engine bore clearance.  This is why quite often an oil pump replacement with tighter clearances doesn't solve sumping.  Max Lambky  11-4-10

Cam Timing Restoration:  by Max Lambky

More often than not, when a total restoration is undertaken, there will be a mismatch of parts.  Usually the timing chest requires much attention.  With old iron it's not uncommon to find that cams have been replaced.  This is sometimes due to rounding off the lobes to an unusable state, but is more commonly due to after market performance cams, and due to the fact that factory racing cams were installed to enhance the bike's performance. When racing cams were installed properly, the performance was enhanced, but often the cams were improperly installed, causing an actual decrease in performance.  The reason usually was due to improper positioning of the cam gear to the camshaft.  During installation of the camshafts, where the camshaft and the gear weren't properly aligned, and the builder relied on punch and scribe timing marks on the two cam gears (the idler gear, and the half time pinion gear) the proper cam timing suffered, causing poor performance.  To eliminate the possibility of improper cam timing after restoration, the following procedures are recommended. 

First you have to attach a degree wheel to the crankshaft.  On an assembled engine, remove derby, clutch, and primary cover.  Clean exposed nut and crankshaft with brake cleaner to remove oil.  Wipe clean.  Apply adhesive backed Velcro to crankshaft end.  Apply adhesive backed Velcro to degree wheel.  Affix degree wheel to crankshaft, achieving a reasonable degree of centering.  Attach hand made pointer to any primary cover bolt hole that's reasonably close to degree wheel.  Sharpen pointer to enhance readable accuracy, i.e., pointer to degree wheel. 

Remove the following items timing side.  Four rocker caps, two intake valve spring cover caps, four push rods and adjusters, timing cover, cam spindle steady plate, half time pinion nut, cams, (both front and rear on twins) idler gear, timed breather gear on B's and C's, half time pinion gear.  Don't remove half time pinion gear key from crankshaft. 

Remove sparkplugs.  Install handmade stop in rear sparkplug hole.  Stop is made by removing all porcelain from a sparkplug, inserting 3/8" rounded rod, so as to provide a protrusion of approximately 1 3/4" extending from the bottom of the threaded steel portion of the sparkplug.  Weld or braise rounded rod to hold secure. 

Turn the crankshaft in the direction of rotation until piston hits special tool stop.  Procede carefully, damage to piston is possible.  At the pointer, with a felt tip, mark the degree wheel.  Now turn the crankshaft in the opposite crankshaft rotation.  Do the same.  Mark the degree wheel at the pointer.  Remove piston stop.  Mark the degree wheel half way between the two pointer marks with a felt tip.  Identify the mark as TDC.  Turn crankshaft and align TDC to pointer point. 

Next determine the manufacturer's recommendation for intake valve opening.  All cam grinders producing after market cam grinds will provide this information.  MKII Lightning cams work best for a wide band power range, using the opening figures of 50o before TDC at .010 off the seat.  We'll be using the procedure for proper cam timing, with the MKII cam intake opening figures.  Of course this would only apply if you're timing MKII cams.  Obviously you'd be using figures supplied by cam manufacturers if their cams were being used. 

Next position the rear cylinder's piston 50o before TDC.  This is done by rotating the crankshaft 360o in direction of rotation, stopping the crankshaft at TDC, pointer at TDC, then turn crankshaft counter to crankshaft rotation by 50o.  With a felt tip, mark degree wheel R 50o BTDC.  R indicating rear cylinder.

Place a dial indicator on the intake valve stem's exposed end.  Remove the exhaust cam lifter on the rear.  With a screwdriver lift the intake lifter, and insert rear cam on cam spindle.  Install rear intake pushrod in rear intake cam lifter.  Insert valve adjuster.  Adjust lifter, taking valve lash from adjuster and valve lifter, i.e., lifter is on heel of cam.  Install cam idler gear.  Turn idler gear counter clockwise until dial indicator reads .010 lift.  The intake valve will be .010 off of it's seat.  Hold idler gear in this position.  Now take half time pinion gear and find the keyway of the pinion gear, which lines up simultaneously with the mesh of the half time pinion tooth with the idler teeth.  Slide the half time pinion home.  Relax pressure on the idler gear.  Check that the .010 opening is retained on the intake valve.  If not, redo.  If so, go on to the next step.

Remove the rear cylinder intake push rod.  Mark the idler gear mesh, cam to idler gear, and idler gear to half time pinion gear with a felt tip.  Rotate crankshaft in direction of rotation 360o+50o.  Move front cylinder exhaust valve lifter, holding in place with a dab of grease.  Install front cam on cam spindle.  Install intake pushrod.  Lift front intake cam lifter with screwdriver.  Insert cam in any position on idler gear, as long as the heel of the cam is adjacent to the cam lifter.  Install pushrod adjuster.  Adjust and eliminate valve lash to zero clearance.  Move dial indicator to end of front cylinder intake valve head.  Adjust dial indicator to zero.  Lift intake valve lifter until indicator reads .010 lift.  Remove front cam by sliding on spindle until idler gear and cam gear release mesh.  Turn cam gear in direction of rotation until mesh is achieved between idler and cam gear, and a slide fit is achieved, lifting ramp cam lobe to intake cam lifter.  Relax pressure on intake lifter.  If the dial indicator still indicates .010, the cams are precision timed to each other and to each piston position, both front and rear cylinder.  For this step to come about the first time is wishful thinking.  More than likely you'll have to push the cam out of it's gear bore with a hydraulic press.  Refit cam to gear relation by rotating gear to cam slightly.  Note which way you should rotate the two parts when going through the steps to achieve a slide fit that's lobe to lifter, and cam gear to idler gear.  In most cases it takes more than one stab to achieve the .010 off the seat, and a perfectly coinciding mesh with the idler gear and the cam gear.  This last step can't be over emphasized.  As this is the step that precisely times the cam gears to each other and the piston position to intake valve opening. 

On the B's and C's, where a timed breather is employed, proceed as follows.  Turn the crankshaft counter clockwise 50o.  This will put the front cylinder at TDC.  Then rotate the crankshaft in crankshaft rotation 15o.  Locate the port in the breather spindle.  Locate the port in the geared breather.  Turn the breather counter clockwise and time the opening of the breather.  The knife edge of the breather gear will coincide with the leading edge of the breather spindle when the breather gear to front cam gear is in mesh. 

Now you've timed the cams and the breather without the use of timing marks.  If you've followed the above procedures, your timing will be far more precise than 90% of the Vincents on the road.  Remove all existing timing marks with a Dremal sander.  You can now remark all of the meshed gears that constitute the cam timing gear train, plus the timed breather.  Remember to mark the half time pinion keyway as well.  You can now reassemble the motorcycle using the new timing marks with confidence that the cams are properly timed. 

If you're tuning for speed, the keyway in the half time pinion is so designed as to allow a veneer timing of the pinion gear.  The rule of thumb is if you were to advance the cam timing a tad, not more than 10o, you would increase bottom end torque.  If you were to retard the cam, again not more than 10o, you would move the torque curve higher, closer to top revs.   Max Lambky  10-29-10


To remove all excessive clearances in the timing chest to include pinion to gear clearance, side slop in cams, idler gear and followers. To insure positive follower to cam relationship (in other words the followers must run dead center on the cam lobes and stay that way. )  Remember, if there's room for something to bang around in, it will bang around.

Materials :
1, Good Cams--with bushes that fit the spindles .0005-.0015".  New bushes can be found at a bearing supply house and center honed to size by any good machine shop.
2 . Good Spindles--No ridges at all--no wear. I recommend G. Emmerich's spindles for reasons that will become obvious later.
3. A round Idler Gear (Chicago Steel) or check yours. Aluminum is good too--but it must be no more than .002"out of round-- and .002" is a bit much.
4. Good cam followers--I'm convinced there is no such animal. But the followers must be re-ground true to the pivot hole. Also many followers have oversized or out of round spindle holes--throw them away !
5 , One Piece Idler Boss--¾ thousands--1½ thousands clearance, clearance between idler pinion and idler boss.
6. A Good  1/2 Time pinion Gear--The 1/2 Time Pinion comes in several over-under sizes won't know which size you need until you set up your cams & Idler Gear.
7, Three packages of  PSW Brand Arbor Shims in 3/8", 1/2'' and 5/8" i.d.--Precision Steel Warehouse, Inc., 3500 N. Wolf Rd., Franklin Park, IL 60131. These are usually available at a good machine shop supply house. Make sure you buy the shims without the keyway notch. They come in packages of assorted thicknesses for about $3.00 per package.

1, Start with the cams. Place cams on shafts with a washer under the spindle nut to take the place of the steady plate. The thickness of  this washer is meaningless what you want to discover is the side to side play of the camshaft with the E95 in place, You want to reproduce its actual running condition. (Here comes the scary part which I'm going to get flack about.) There are t w o ways to get minimal side clearance. Shim the cam at the rear with the 1/2'' arbor shims or move the spindle. If the side clearance is tight you have to draw the spindle out slightly which is done  by putting large washers on the cam then using the spindle nut as a puller works great. It's also a test for loose spindles which can be fixed well with Loctite. The reason I recommend George's camshaft spindles is because of the fact that they are very tough. I don't like to shim the camshaft if there is excessive side clearance I assemble the cam as above with the E95 thrust washer and a washer tightened down on the shoulder of the spindle and I hit the spindle with a hammer! (A Harley- Davidson type.) George Emrnerichts spindles are so damn strong that we have done this without protecting the end of the spindle with no damage but, with stock spindles, build up a pile of washers (3/8") until an old nut threads on without exposing the end of the spindle--then hit the nut. The object here is to take the brunt of the blow from the threads to the shoulder of the spindle itself.

Now I'm going to hear how this method ruins the case-to-spindle press fit and all that. If you're really worried heat the case around the base of the spindle--but I don't recommend it because you can overheat the spindle. Moving the spindle a few thousands in one direction or the other will not hurt anything. Now that correct cam clearance his been obtained it's time to assemble the followers.
With the cams loose on their shafts (you have to be able to take them on/off the shafts) put one pair of followers on their spindles as described in the Vincent books--do the above thing to the follower spindles. put a temporary washer in place to act as the steady plate and tighten the follower spindle nuts down. (Remember that to remove and insert your rear intake follower your compression release rod must be removed). Slip cam on its spindle and, if your heads are off, look down through the push rod tube holes and see if ox not your followers are running dead-center on your cam lobes. If the heads are on, you have to use a flashlight and lots a neck bending to see around the camshaft gear. If I can't look down through the push-rod holes I judge the cam/-follower relationship by lining up the edge of the follower with the edge of the cam lobe. It's helpful here to have a pointed rod to poke in there and actually feel for any over-lap one way or the other. The object here is to either add to the thickness of your ET98s or subtract from them to get your correct case-to-follower distance with perfect cam/follower alignment. This is where you use your assortment of 3/8" arbor shims.
After you've established correct follower placement you must reassemble all the spacers ET99, ET99/1, ET99/2, etc. with the washer that acts as the steady plate--tighten the spindle nut and check side play. Remember now that the follower is spaced to the case and you mustn't change that
spacing. All spacing for side thrust must be done on the outside (offside) of the followers. If after tightening the spindle nuts the follower is jammed you must take material off your long spacer (ET99,/1,/2) until the long spacer will turn with the nut tightened but having no side play. You don't want the longer spacer to drag, but you don't want side play either. If you do have side slop, you use your 3/8" arbor shims wherever they will fit on the spindle without fouling the camshaft gear wheel.

Your front exhaust follower is a special case due to its cute location, You do same as above--the trick here is to "glue" your arbor shims to each side of the depression in the case with "assembly lube" or light grease, This holds the shims in place while you carefully insert the follower between them and insert the ET30/3 spindle snug it down and check side slop--KEEP WORKING UNTIL YOU GET IT RIGHT--NO SIDE PLAY WITH THE FOLLOWER DEAD CENTER ON THE CAM LOBE.

Fitting Idler Gear:
With cams and followers in place check fit/side play of large idler you want to shim this (if necessary) to run true with the cam gears.
Fit idler boss in place--run the 3ea ¼" nuts and washers down snug--just so you can barely move the idler boss up, down and around. (That's why the holes in the idler boss are oversize.) Slip the idler gear into place without +, time pinion in place. Move the idler pinion up until there is 0 (ZERO) backlash between it and the cam gears. Tighten the three idler boss hold-down nuts. Check for zero backlash by holding the idler tight and trying to rotate the cam gears back/forth. If there is any back/forth play you must loosen the idler boss and correct it. When this is done rotate the idler gear. THERE SHOULD BE NO TIGHT SPOTS DURING 360 ROTATION. If there is the idler is a bit out of round and you must re-adjust the idler boss to allow for the high spot; Dig?

When the large idler is fitted to your satisfaction, slip it off the shaft, Install the half time pinion on the main shaft, Re-install the large idler. If you can't get it on, the 1/2 time pinion is too big and you need a smaller size. If it goes on and there is play between it and the half  time pinion, it may be too small, you need a bigger 1/2 time pinion. You want ZERO to .002" clearance between the idler and the 1/2 time pinion. .002 backlash is almost unnoticeable. It would be nice to have an assortment of over and under size 1/2 time pinions at this point. Good Luck.
A good trick is to remove one large idler boss hold down nut at a time (so you won't loose adjustment) and apply Loctite and re-fit it. I don't believe in punch locking; it ruins parts and makes taking things apart hard, Loctite works! Believe in it.

Now, with everything in its place, fit the steady plate after you've lined up your timing marks of course. Use blue Loctite on plain nuts here instead of punches and folding washers. Don't Loctite the four oil-feed shaft nuts--they are self locking nylock and won't 'unscrew anyway. Another problem you run into with punch locked studs is the fact that many times the stud comes out of the case instead of the nut corning off the stud. If this occurs, take the stud out of the case, hold it in a vise or Vise grips on the unthreaded portion and take the nut off. Dress the punch damage with a file, make sure the nut will start on easily. Now put it back into the case with Loctite "Stud & Bearing Mount" (part #2226).'s red. Use Loctite spray primer to clean the threads. This is much stronger than the Loctite (blue) that you use on nuts. This way the nut will always release leaving the stud in the case where it oughta be, DON'T PUNCH LOCK, DAMN IT, I have never written directions before so I may have over-looked something--my hand is tired- [what about me, mate? (the typist and so It s my head. [ just like Gumby of Monty Python, "My brain hurts!]  But the general idea is there. And nothing can replace care/patience, I suggest everyone read Zen and the A r t of Motorcycle Maintenance, it's more important than any Vincent manual--read it!

I always put transmission in high gear, not low, when bumping with the rear wheel to set valves, ignition timing etc..  Far less piston travel when you bump the wheel, easier to bump, finer adjustments.  The engine turns over appx three times slower in high than low when turned by the rear wheel, making tasks such as reading the timing spoke, turning the engine against valve spring pressure, etc. much easier.  Paul Zell 8/9/10

Camshafts: I have been told that Megacycle bought the Emmericj/Andrews cam designs.  I have those in my bike and I was told to split the overlap at TDC at .050" lift, which is what Max, Tom, and others have basically been saying.  This means if intake opening is at 0 deg and exhaust closing is at X deg, make the intake opening at 0 + X/2 deg.  Then you can retard that for more peak power or advance it for more low down torque.  That is over-simplified, but you bike will run fine at 0 + x/2 deg.   Bruce Metcalf  7/28/10
Shifted Flywheels:   If your feed quill shows rubbing / wear on both ends  - but on opposite sides is indication that flywheels have shifted.   For  more dramatic  evidence of shifting  obtain a  length of  quality 1/4 inch dia. steel drill rod a foot long or better and dead straight.   Slide this up into the right side quill passage untill  it bottoms out.  Give it a light tap to seat it.  With someone rotating the motor via the kicker you kneel and observe the end of that rod end on.  If it spins with a decided oval pattern to the movement  that's a pretty good indication that the flywheels have shifted. The nearer to no wobble the better.  Sid Biberman 7/28/10
Valve Timing: All you need is one dial indicator to time the cams.  Remove the half time pinion gear from the crankshaft.  With a degree wheel, place the rear cylinder 37o before TDC.  Remove all of the pushrods except the rear intake.  Place your dial indicator on the intake valve head at the top.  With your fingers, grab the idler gear and turn until the intake is .050 open.  Lock the idler and cam teeth with a screwdriver in that position.  Now you can find the keyway slots that best time the cam in that position, by sliding the halftime pinion gear on the crank.  When this position is found, the key should tap in or slide in rather freely.  Now rotate the crankshaft, using the attached degree wheel for reference, 410o.  This will put the front cylinder 37o before TDC.  Place the dial indicator on the front cylinder intake valve stem head.  Mark the degree wheel and the pointer so as not to loose the 37o position.  Back up the engine 50o.  Remove pushrod from rear intake valve, and install intake valve pushrod on front cylinder.  Adjust properly.  Rotate engine in direction of rotation to the previously marked timing position.  You should have a reading with the front cylinder at 37o before TDC of .050 on the dial indicator.  If you don't have the .050, the front gear will have to be pushed off of the front cam, and relocated, until you achieve the .050.  Max Lambky  7/9/11

Porting a standard head
to it's maximum requires 90o plate flange bolted to the head.  The plate flange should be 3/8" thick, and it's manifold mounting flange studs should be 2 1/4" from center to center.
To accomplish the mod, remove the two studs in the cylinder head.  The threads are one quarter twenty.  Take two quarter twenty Allen head screws, one inch long, and take the outside diameter of the Allen portion down .010.  Manufacture a flange from aluminum, using the dimensions above.  Manufacture the flange with counter sunk mounting holes, so that the flange can be bolted to the cylinder head with a thin paper gasket.  You can now take the port to it's maximum size, and achieve much better flow characteristics by raising the port to it's maximum.  You now have a wider horizontal bolt pattern flange, compared to the perpendicular narrower bolt pattern flange.  Make yourself an aluminum manifold, keeping the bend as high as possible.  The manifold should be a spigot mount, opened up, and blended to a 36mm size.  A 36mm Mikuni is my choice for carburetion.   Max Lambky  3/12/10
Valve Timing:  Timing marks may not be correct as the wheels may have been pressed off the cams at some time, checking timing by lift is better.  Equal lift on both inlet and exhaust at around four degrees before top dead centre seems to be the ideal to aim for.  There is no need to remove the timing cover, just put a degree disc on as normal.  I checked mine for the overlap position and with Mk1 cams the the rear came out with equal lift at 7° and the front 5°.  It might be possible in this instance to play around with the timing pinion keyway to get one cylinder or the other closer to 4° but as it runs fine and there is no spray from the carbs it is OK for me. You may be able to remove the valve caps and do a rough check by eye without dial gauges to find the "rocking" position of the tappets.  Eddie  5/11/10

Valve Timing:  A foursome of dial gauges will compare lift on the front & rear respective cam followers by reading off the top of the pushrods while still in the engine..50 degrees apart of course..The amount of lift should be close at any given amount prior to ( intake ) or after ( exhaust ) TDC..gas tank off - mounted by magnet to the oil tank..  Bob Collings  5/11/10
Valve timing:  The valves should have equal lift at between 6 and 4 degrees BTDC.  This works for every cam (Vincent or otherwise) I've ever timed. If inlet and exhaust valve closing and
opening overlap, they have to overlap somewhere, and on every motor for which I've plotted a valve lift diagram, "somewhere" turns out to be about four degrees BTDC.    Tom   2/22/10

Cam Slots: In the Richardson book, there is a drawing of the timing chest.  With the rear cylinder at TDC, the slot on the rear cam is parallel with the rear cylinder bore and the slot on the front cam points straight down.  Bruce Metcalf  5/11/10
Timing Chest: Unless  the spindles are way out from being equal in height, I would suggest the last thing you should be doing is moving them. The interference in the crankcase is critical and once in place should not be messed with unnecessarilly. The positioning of the various types of washers and shims is necessary, but the number used to gain the correct result is not. Spindles can easily be built to the same length with the odd correctly placed washer. Then it is essential to get the endfloat right. It is hardly likely that the same size washers and shims will achieve the desired result after over 50 years of use and replacement. Shims can be obtained in various thicknesses and provided you replace them in the positions originally used the number doesn't matter. It is only a matter of common sense to end up with a plate
that is not distorted and the correct endfloat on the various components. It will take some time and a few trial fits, but the end result is well worth the trouble.   Derek Peters  1/28/10
Timing Chest: What was not immediately obvious to me was that there are two outboard washers on each spindle, the outermost is clamped between the plate and the spindle, and takes the thrust. The other is the shim and runs loose. I reckon that 5 to 10 thou end float is OK (partly instinct, partly because Trevor told me so), but what is important is that the stick-out of the spindles above the crankcase is the same otherwise the plate distorts. They should be 0.419 to 0.424 proud. I made a slide hammer to adjust it, but it took a while. It was actually a very satisfying job, assembling the timing gear piece by piece insuring that it hadn't tightened up after every stage. So, taking your point, I'd studdy the literature (ideally KTB, the Instruction Sheets, and Richardson, then I'd check very carefully that all the shims are in place when you lift the plate (checking the back of the plate to make sure none are clinging there), then that all the spindles are the same height, then proceed.  Tom Gaynor  1/28/10

I set up big ends with .001" clearance plus or minus a couple tenths. Dan's math is correct as usual regarding rock.  (1/64" is good for a standard crowded roller ass. An Alfa 1/32" is correct. Each gives you .001 clearance. )  Rather than rely on a rocking figure I prefer to hone the big end eye to zero clearance hand fit then measuring with a bore gauge hone the required clearance.    The INA bearings are a wonderful innovation. Amazing the load and rpm they can handle.  Steve Hamel  1/7/10
Primary case oil level:  A simple, but time-saving mod is to remove the primary chaincase level screw and replace it with one that projects  1/2" into the case. Then, if as on my bike, an erratic primary chain level merits regular checking, it is easy to see if the oil level is over or under the projecting screw by looking through the inspection cap directly above.  Tom  12/14/09
Oiling procedure prior to initial starting :  If  the oil isn't already poured into the top member oil tank.  Proceed  thusly.  About  2 & 1/2 qts will be enough if you follow these other directions.  Then after  running  it a while,   {even a brief  ride twice around  the block} do then.  Fill to the normal level, ie about 3/4 inch below the filler tube.  Check for leaks afterwards at Every  banjo bolt, etc.  Some loss by  oozing is common,  snug up as needed, but very carefully.  Any faulty seal needs being replaced.
There are 4  things  to do, important if  rapid wear is to be avoided .
#1  Back off about 2  turns the lower banjo bolt at the bottom end of  the large feed pipe, a pan beneath it.  Wait till oil issues forth  freely -  not the early bubbles but a clear oil  flow.   When you see clear oil tighten the banjo bolt carefully { this to let the air column escape ensuring that oil is present at the pump entry port}.  Tighten carefully so as not to fracture. Clean off the fittings.
 #2   At the forwards end of  the timing cover facing  you is another banjo bolt - a longer one.   Both hex heads are the size of a spark plug hex - 13 /16ths.  When unscrewed slide this one out.   Using a   hand  held oil pump can - enter its spout into the hole about 3 or 4 inches,  this will project into the oil filter chamber - right into the center of the filter element.   Pump this empty chamber full or nearly so to  lessen the time needed to circulate the oil when started.  Pull out the pump and replace the banjo bolt.  Carefully tighten.  Wipe away any spilled oil.
 #3   In the center of the lower side of  the big end feed quill is a small screw,  remove and pump in several strokes of oil to flood the rod big ends.  Replace the screw.
# 4   Remove the center 2 rocker caps.  If they feel to jam Stop.  Turn back inward - rotate the motor a bit to lower the rocker arm and try again.   Now,  refill the squirt can and pump its contents down both pushrod upper openings - 6 full shots in each one.  Replace the caps.  This will flood the cams and followers so they won't rotate dry,  then the oil will run down into the sump where it will be picked up by the pump to be returned to the tank, oiling the rockers as it goes through the return pipe.  If  all this is done correctly  you should see oil returning in the filler neck very soon after restarting.   I'd  guess within a minute.
#5  Check the gearbox oil level - should show on the bottom of the stick.  If  not add a bit more til it does.  This holds a full quart from drained.
#6  Check the primary case level.  Oil should be up to the level plug opening and just ooze out a little bit.   Not drip heavily.   If so let it drip till it near stops.   Replace the short bolt and just snug up, careful not  to damage the threads.    This is a steel bolt  in soft alloy and can strip.   Sid   12/14/09
Checking the Valve Timing:  I don't bother with opening and closing points, it's far too inaccurate.  I set my engines up with both valves equally open at between 4 to 6 degrees before TDC on the exhaust stroke, coming up to the inlet downstroke, and it works like a dream.  You know if you are on the compression stroke by mistake,  because at 4 degrees before TDC both valves will be closed.  This method of valve timing is also much more accurate if the cams have any wear.  Roy Cross  11/6/09
Excessive Oil Consumption: Fairly common this condition causes high oil consumption and lowered performance,  oil fouled  plugs.  Sited on the  bottom of  the  cases - on the right side beneath the pump chamber is a small threaded plug with a straight slot.  This short grub screw simply seals off a drilled passage  eading  to  the pump.   If  loose or poorly sealed air will seep in past the threads- weakening the vacuum {suction }that lifts the oil out of  the sump and delivers it  to the  scavange side of the pump where it can be returned to the oil tank.   And so the level rides higher than normal,  wetting  the flywheels  where it  is flung  too heavily  up the bores.  If  in doubt,  remove this plug  and clean all threads involved, and then reseal effectively using  Permatex or other good sealant.  Allow  to harden .     Sid   10-24-09

Yes, the plug should be sealed so as to make Air Tight - and Oil tight !   It is a cross drilling used in machining to connect drillings for oil pump, then sealed with the plug.. common practice.  Mike

Has anybody fitted a magnetic plug to thier oil system?  How about a magnetic screw in the end of the oil quill?   How about a magnetic plug in the underside of banjo bolt, or even drilling and taping a thread into the top of the banjo bolt and threading in a magnetic drain plug.  That would catch metalic particles just before
they enter the oil pump.  How about inserting a union on the return line to the tank and getting a plug into the wall of the flow stream?   Richard Friedman  10/21/09

I put a magnetic sump-plug in my Manx. When it came back from my Manx engine-building guru, the plug had gone. I asked him if he'd lost it. "No, I took it out. Magnetic plugs collect metallic particles, and Manx motors Always shed magnetic particles. So why stress out by collecting them, and agonising over them? They'll be there anyway." So I left it out. The bike still runs, lambs still gambol in the meadows, the sun still shines, and there's one inevitable thing less to worry about.
Think of it like worrying about death. What's the point? You Are going to die. Vincent (and Manx Norton) motors Are going to shed magnetic particles. Why dwell on it? To paraphrase, someone recently quoted PEI as saying "if it isn't making distressing noises, forget mileage, ride it". With earplugs, my constant recourse, Vincent riding is a virtually stress-free occupation. And when I pull the non-magnetic drain-plug for an oil-change, it remains stress free.  Tom  10/22/09

Bend a bit  of SS lock wire into a kinda cage containing a small strong  magnet and  form a loop that locates it beneath the returning oil  squirt,  so that the oil flows  over it.  Hang the loop over the chain oiler adj. screw.  Sid  10/17/09.

Easy to check breather timing without disassembly.  Blow into the breather pipe while turning the engine over, breather should close just after (30 deg) BDC of rear pot.    Paul Zell   9/2009
A Manx pump is reckoned to deliver 42 gph at 7200, which is 0.77 pints per 1000 rpm. The Vincent oil pump delivers about 0.15 pints/1000 rpm, a modern Ducati delivers about 6 pints/1000 rpm.  Sunbeam  8/19/09

The original Picador two-start oil pump mod consisted of just a "magic ring", a higher pitch drive worm, which turns the stock pump faster. Later and current two start pumps come as matched sets that require a matching worm and pump, and are not interchangeable with the early one. Steve Lindbloom  8/19/09

2 start oil pump:  I don't violently disagree with david, but my oiled plugs problems were cured by fitting new pistons in new, cylindrical muffs, and replacing
my (worn) valves and guides with new valves and sealed guides. Granted, at 48,000 miles, this was due, if not overdue.  Make sure you buy a two-start worm. Perhaps it was the way I read the  literature, but it wasn't initially clear to me that that is essential.  I'm not sure about the "excess oil" argument. A two-start pump
scavenges at double speed too. On balance, I'd say one has nothing to  lose by going two-start. It'll give you about 1/2 litre per 1000 revs.
My Ducati Monster delivers 35 per 1000 revs.  Personally I reckon much "oiled plug" trouble is caused by running  plugs that are far too cold. Before the overhaul I reduced my oily plug problem by 50% by changing my NGK 6's to 5's. 6's didn't get hot enough to burn the oil off.     Tom 8/14/09
Cylinder Liners:  L.A. Sleeves offer well proven -well made liners in oversize dimensions  used with full success for many years.  Coventry Spares generally
carry liners in + 40 and  + 60 at reaonable prices of fine quality.   After removal and deep cleaning, a pair of  finned cylinders are closely examined and measured / compared , the purose being to Blue-print them to identical thickness top to bottom as well as being bored perfectly central and perpendicular to parallel top and
bottom surfaces. Their inner bores are taken out enough to fully clean-up and provide a smooth dead straight and round surface.   Unwise to bore any larger than necessary as it loses cylinder strength /rigidty.   The new liner is mounted on exanding mandrels and it's outside diameter is reduced dead true to its center and fully larger by .004"  than the i.d.of that muff selected to mate with it.  At the exact distance from it's top where this liner shall emerge from the bottom of that muff -this sleeve is taken down to suit one or the other main case register mouth bores - to a fine finish and a snug slide-in fit into the bolted together cases, and marked to identify this mating for correct assembly.  The remaining  liner and muff are likewise prepared and mated.  The cool liners are fully entered into the heated alloy muffs and held hard-in until cooled off.  The top recess and head spigot already having been reformed to original dimensions. Later, after final double grit lapping, we like to see an air gap of  .003" between the two broad faces, the differance in grain size.  This will close up and come solid upon application of the correct torque loading figure, i.e. 30  to 32  ft.lbs. maximum.  No more is needed and actually harmful.  Before final bore and hone procedure, the thrust face oil delivery holes are sited    carefully, these to break through below the oil-ring grooves - at BDC - not into them.  Finally we prefer to fit a lower liner mouth girdle clamp to prevent any bell -mouthing  while boring and honing.  Sid   7/15/09 
Broken nuts on
locking rocker feed bolts is not an unheard of problem. People seem to not take into account that the load exerted by 188, the banjo bolt, is transferred down through ET100 mod. to the rocker feed bolt nut. If one of the banjos is leaking and 188 seems loose, suspect that the RFB nut may be broken and pulling up.  Phelps  6/30/09
Always run a small drill bit with your Fingers into the 1/4 x 20 threaded
primary and timing case holes in the crankcase before inserting new cover screws. The bottom fills up with RTV and all sorts of grit and debris ( from previous owners..) and the screws can strip the case threads by hydraulic lock.  Jim  6/22/09
Locking Rocker Feed Bolts :
Open up the rocker bush top hole from 5/16 " to 3 / 8 " for top hat nut to fit inside.
 De- burr and dress to fit properly.  Ensure oil feed holes are not blocked .
Top of  rocker will need grinding to clear the top hat nut as it will bind on full movement.
Use a slightly undersize 1/2 " rod or old bolt as mandrel for checking  instead of  keep inserting and removing rocker pin.
Check to see rocker pin is not too long as will bind on tunnel when fitting.
Remove any metal chips or dirt etc. from all parts.   Grease and install .     Mike White  6/20/09
Head Nut Torque: PEI  gave me this figure.  30 to 32  ft lbs.   This  leaves a natural " give "  or elasticity  necessary  in the long  studs to allow column growth  when fully hot.    Apply in stages criss cross,  leave sitting overnite,  re check the following  day.  Sid   6/17/09
Welding rod 4043 will work perfectly for the Vincent crankcases. The main consideration is cleanliness. Cases should be pre-heated and a stainless steel brush used for cleaning. If a grinding wheel is used ( to Vee a section for example) make sure you do not use a wheel that will ultimately contaminate the aluminum. Thus, if you can use only a file to "vee" your part, do so. After heating the part once to clean it, and clean is the most important word here (if you are welding a part that was subjected to oil, the devilsh stuff will work its way to the surface easily) the part should be pre-heated to 200-300 degrees. You can check it with a heat stick available at any welding supply house.  Of course I am referring to welding the piece with a heliarc (TIG welder). Carl Hungness  5/23/09
D breather cap will take a double ended BSP fitting as used in a fuel petcock. It screws right in.  Such a fitting, with BSP at both ends, will take a one inch  length of   1/2 inch ID rubber fuel line, the distal end  of which will take a pcv valve with a 90 degree bend, easily  purchased at any aftermarket auto parts store. I used a hose clamp ("jubilee") to secure the hose segment to the distal end of the double ended fitting.The above setup, when placed on the rear cylinder inlet rocker area, seems to me to allow maximal flow as the rear cylinder set up is a straight shot to the timing chest  with a big orifice as compared to the 2nd cylinder exhaust. Plus the pcv valve  can be postioned perfectly horizontal in thisposition with minimal distance between the cap and pcv.valve.  You then run a short length of fuel line from the vertical end of the pcv and it goes between the back of the crankcase and  the RFM, or you could run it to your chain if you preferred. All of this was done after blocking of the original breather orifice with the brass plug. Most of this I stole from others, but the series D cap the 1st cylinder inlet valve cap position, the  BSP double ended fitting, the short run between the valve, the ability to position the valve horizontally with a subsequent vertical run seems a happy combination.  I've got a lot of other pcv valves and hoses and other positions I tried!   Charles Cannon 5/15/09
The answer to
getting an oil-tight bike lies in the accumulated knowledge of hundreds of Vincent owners. The problem is getting all of that knowledge into one bike!
Rocker oil feed banjos:
1. If they have been chromed-many plating companies hang such parts in the plating tank on a twist of wire. This leaves a tiny groove in the plate across the mating surface, through which oil will seep. I always rub my banjos on a flat piece of emery paper to get a totally flat surface.
2. Most banjos have become slightly dished over the years, from the 1/4" BSF bolt head, so I invert the rubbing process to return the upper face to a flat surface.
3. It is a good idea to change the normal 1/4" BSF bolt to an AMAL carb petrol
feed bolt, which has a 1/4" thread, but has the head of a 5/16", thus spreading the pressure over a wider area of the copper washer and avoiding the dishing in the future. These bolts are available in stainless.
4. I always drill and wirelock the rocker oil feed bolts, as they tend to slacken slightly. (See 6)
5. Ensure that the bends in your oil feed pipes align the joints properly into the union, so that the conical ends fit square into the union. (I have cheated on two of my engines by using flexible Aeroquip hose, thus the union can align itself).
6.The ET189 fibre washers tend to flatten in use, thus spreading, getting thinner, spreading some more, and eventually splitting. Either use a suitable Dowty washer, or Neal Videans new washers, or as I have done, turn some aluminum rings to fit exactly round the ET189s, which stops them spreading and so they don't get thinner, which loosens the bolt.
If you do all the above, your rocker oil feeds will be oiltight.   Dick Sherwin  4/24/09
The traditional way to
measure gears is the over-the-pins method.

If you just want to grade them from small to large,  find two rollers (bearing rollers) that fit approximately 1/2 way into the tooth space.  Place them between opposite sets of teeth (for even teeth) or staggered by one tooth opposite (for odd numbers of teeth) and measure acccross the pins.  You will probably find this will vary if  you work your way around the gear taking successive measurements.  This could be due to wear or pitch diameter run out.  Another useful way to gage your gear is to rubber band a set of rollers around the entire gear and spin the gear on centers with a the rollers passing a test indicator.  This will give you a sense of the pitch diameter run out with respect to the axis of rotation.

Sophisticated gear manufactures make a test gear to exact dimensions and run the manufactured gear spring loaded against the test gear.  Then then measure the displacement of the manufactured gears axis as it rotates.  This provides a quick cumulative measure of the inaccuracies that result from gear manufacture.

No gear is perfect.  You need to set up your gears so that there is zero interferance in the worst case condition and live with the noise as your imperfect gear rotates into positions where the mesh is less than ideal.

Incidentally, when a gear tooth is transmitting power it deflects a tiny bit, so that the set of gear teeth about to come into contact are no longer synchronized and they collide a tiny bit when they first touch.  You can see this on some gears as evidenced by a contact line across the gear at about 2/3 of the gear tooth height.  Fancy gears have the profile slightly backed off at this location for improved durability.  Another solution is to use an aluminum gear whose sacrificial soft surface will abrade away to provide optimum performance.    Richard Friedman  4/15/09

Routing Oil Lines: When I did the Prince, the feed tube was a little battered and the Spares co. was out of stock. I cut off the battered length and increased the length of the herringbone flex hose. I have since obtained a new feed pipe but haven't yet fitted it. One reason is when I fitted the the longer hose I borrowed a ferrule clamp which nips the hose/pipe very tightly and I am loathe to remove it. Two advantages of leaving alone, first it is hidden behind the side panel and two, by slackening the oil feed union I can swivel the pipe out of the way when removing the kickstart cover, with only a slight drip of oil.  Paul Craven  4/17/09

Routing Oil Feed and Return Lines:  I concluded that what you want is impossible. I grew tired of dismantling the entire bicycle to get the kick-start cover off. Since I don't care much about originality (although I do care about aesthetics, see recent posts about Italian bikes), I inserted a piece of herringbone (i.e. authentic...) tubing, in the feed line and took the oil feed BEHIND the rear engine plate, tie-wrapped on to the plate to stop it drifting into the rear chain. Now I can wiggle the kickstart cover off past the return line (the one to the rockers) without disturbing either feed or return. (Feed's the one that creates a 6 foot pool of oil under the bike when disconnected at either end.)  Although prejudiced in my own favour, naturally, it doesn't immediately strike the eye as Wrong.  Tom 4/14/09
Oil Lines: Dick Sherwin cuts his pipes off near the banjo's and fits braided aircraft type flexible armoured tube in the gaps. All very neat.  Roy Cross  4/14/09
Bending Oil Lines:Fill em with cerrobend and bend em by hand then melt out with boiling water. Tom Kingman
Bending Oil Lines:  My still-making friends use salt - you have to crimp the ends to hold it in, but it's cheap, and easy to dissolve afterwards (I've known plenty of people who have tried sand, and never could get it out again).
Bending Oil Lines: You can use this to bend your tubing. Heat tubing in hot water 200F with the bottom end plugged. Heat Bismuth to 200F in a container sitting in the water.
Pore the metal into the hot tubing, still sitting in the hot water. using a small funnel made from what ever is handy.
 Now bend the tubing as you wish. Tubing will not collapse as it is now a solid.
Ken Smith    4/15/09
Head Joint: With correct machining to the top and bottom  surfaces and good  lapping  technique there will be an air gap between the broad  faces with the head  placed firmly home on the spigot,  the liner top edge sitting properly within its recess.   All  surfaces clean of  compound and debree of course.   A  feeler gauge of   3 or 4 thou. should enter that gap without forcing  the head to rise.  If not  it will not seal,  the actual sealing occuring Not at the broad face --- but  at the narrow inner  surface, iron against  alloy.  The described  gap will  vanish  when the  assembly is  torqued down,  and if  correct  in every way 32  max  ft lbs  should be sufficient,  30  being  usually  sufficient for a street motor .   More  won't  solve the problem ---  but  if  severly overloaded  shall  certainly  introduce  more  troubles  with the motor at full heat .   There  will be no easy answer until  this important detail  is dealt with  -  through  correct preparation  in the machine shop of the spigot / liner  dimensions.   And be sure the liner is fully  home in the muff or it will drop further spoiling  the  work .  Sid   12/6/08
Head Joint: If the head has been on  for years creep will have taken place and the gap will have disappeared.  It is essential to check for the gap when replacing the head.   I found it easier to stick some coarse wet and dry to a board and rub the head on it  to remove 2 thou. Then just grind the liner joint with fine paste.  Ernie Lowinger  12/5/08
Timing Gear Backlash:   The problem is Not in the idler gear but in both camshaft gears,  common with high mileage cams.  There is a cyclic wear pattern caused by the nature of their work loading,  alternately  forcing the springs to compress {thus the wear occuring on one side of the teeth flanks} followed by those same springs driving the idler gear - with a thrust reversal - { they rack back and forth as a result }  the wear now on the opposite teeth flanks.  But seen on only  those teeth doing  the heavy work - not all.   The condition is permanent, only corrected by replacing the two pinions { the shafts can be reused  if  unworn.  Generally the only downside is a  noise generated during running ,  and if you set set the idler position to that compromise location where you can just slide out the big gear with your fingertips -  then that is the best you can do,  this with the Least  or nil lash discernable.   There will  still be  those periods  where  looseness can be felt And  heard {as the cam gears rack back and forth doing their work against the spring pressure} but  its not  a danger,  only  unpleasant and noisy... Or  replace the  gears.  Be sure these are correctly  located on the shafts - critical - and a spot of weld will  keep thm there.  Sid   12/5/08
Mufflers - Cams: Straight through Toga muffler Toga works well with Mk 2 cams and the original spiral baffled muffler will work okay with Robinson 105 cams  due to reduced overlap.   Carleton  8/18/08
Vincent  liners are very often far from round for many reasons besides being  perhaps poorly  machined.   Fit in the muff which might itself be far from true,  also  often loose and thus offering uneven support to the liner within as well as causing liner overheating  due to poor thermal path  to the fins.  Also a common fault  is   overtorqued head nuts causing severe stress to the cylinder structure when hot,  and the muff might not have parallel top and bottom faces thus causing a twist.   All  will cause the rings to work harder trying to follow the liners uneven surface.   With a similar history it's likely that similar problems will be found to exist  in both  cylinders of a twin.   A careless/read cheap rebuild will often have the barrels rebored without knowing that the critical liner to muff fit  is suitable in all the above  details,   and can lead to many headaches with a Vincent motor not limited to the complaint mentioned but also to severe ring blowby,  heavy oil consumption,   fouled plugs and poor performance.  None of this necessary or the  fault of  the design.  Dont curse  your Vincent  ----  but  blame the  machinest.   Or a tightwad   owner choosing the cheapest way to go.    Sid   12/23/07
Timing Chest:  If you were to fit all the listed washers in their correct location and then adjust all  the spindles to give the correct end float then you will more than likely end up with the steady plate being warped all over the place. The  correct procedure is to set all the spindle shoulders to the specified distance above the timing chest face. Then shim the various components to give minimal end float. Whilst doing this align the followers so they fall centrally on the cam lobes. If you end up have to use a couple of extra shims then so be it. An alternative is to use  thinner shims or spacer washers.  The front cam spindle coming out at temperature can be resolved by refitting with loctite whilst still hot, be quick though.   Phelps.  10/26/07
The explanation for there being no (or no need) for thrust washers behind components is in KTB. What thrust loads there are are towards the outside. MO13 is wrong (and it is). KTB shows corrections.   anon
Timing Chest: The shoulders of the spindles should be 0.419" to 0.423" proud of the cover joint face. (KTB Page 154) and they all need to be tight and in order to move them the crankcase should be heated locally.  The spindles should ideally be fitted with the oil holes on the underside since that's where the clearance is.
The idler gear should be meshed with the camwheels with no backlash. The half time pinion should have no more than .002" backlash. (Works instruction sheet No.6).  Whilst you've got the opportunity I think that it's worth fitting the later type valve lifter as both valves can be lifted together. (Details in KTB Page 163)
A small mod. that I find is worth doing is to counterbore the pushrod tube nuts about 1/32" oversize to allow for the mis-alignment which occurs with varying height of the cylinder muffs..   Roy Cross  10/25/07
ESA Springs:   In my experiance  the main cause of  breakage  is  found  in  the varing depths of the drilled  holes  -  and or  these are  packed  up at their bottoms  with debree  from  previously  broken  remnants .    This leads to coil binding  with  early  breakage as a result .  Check  and  clean out all holes with a drill bit  making sure that all are of  equal  depth  ,  and  if needed  deepen to  acheve this  .    Before assembly  grease  all the springs with  disc  brake type  bearing  grease  {  HMP  }   ,  and coil direction  will  not prove a factor  .    Of  course  if the  outer nut  wanders loose   many bad things will happen   so be sure   this goes fully home   and is secure   using  Loc Nut   {   threads  to be  really  clean  first }   or other means  /   or both .   DO  NOT  brutally  force  this nut  with  excessive torque  beyond  the assembly going  fully home  as one  can  shift the  mainshaft  Mills pin  .   Select   the best  lobe nesting  position   for  least  movement  before the outer component  begins  to lift  .  This  makes for  more supple  functioning   of the  ESA  and longer  component  life  .   Sid .

MK 2 Cams: PEI autobiography, page 374. "I decided to retain the exhaust opening and the inlet closing timings of the Mark 1 cams but alter the exhaust opening and inlet closing angles to widen the overlap to 105 degrees and subsequently increase the valve opening during the inlet and exhaust strokes. The full lifts were also increased from .312ins to  .343ins".  Roy Cross  9/4/07
There seems to be an assumption by some that the
cam lift is the same as valve lift, which I believe is not the case. Although the standard rockers are not ratioed (is there such a word?), that is they are 1:1, the physical positioning of the various parts of the train of components gives a ratio which increases the valve lift above that of the cam lobe by about 1.12 .. Thus Roy's quote from Phil Irving of 0.343 (if taken as cam lift), when multiplied by 1.12 gives 0.384, which falls into the ballpark of the valve lifts quoted in practice.   Try measuring your cam lobe against your valve lift as I have just done. Not certain if this has any practical application, though.
Dick  Sherwin  9/4/07

 Cam Lift and Valve Lift:  The latter will be greater because of the amplification via the cam-follower arm.  The question now becomes:  What is that amplification factor?  It would need an original factory timing-case drawing to discover the relative centre-lines between cam-follower pivot, cam and pushrod-cup.  I'm not aware that such a drawing exists.  Peter Barker  9/4/07

Cam and Valve Lift: There are two amplifications. One is straight arm length: a 2" radius at the valve and 1" at the cam follower gives 2:1. But each radius varies as the contact line between cam-follower (or rocker) and cam moves, and the contact point at the valve changes too. I think that PEI discusses this in Tuning for Speed.  Tom Gaynor  9/4/07
One "top tuning tip" is to increase the radius of the cam follower or rocker, which increases valve acceleration. The ratio Is variable, lifting at the tip of the rocker / cam follower initially, and in the centre at full lift, a difference of about 1/4". There's a much smaller variation where rocker touches valve. Vins have flat cam followers (or more accurately cam followers of infinite radius....) but the both radii vary through each cycle.  Tom Gaynor  9/4/07
Ernesto's trick to reducing oil leaks:  He removes the chain oiler fitting, T29, and the Chain Oiler screw in the oil tank is left Open. The stock breather banjo/pipe is plugged, so it will remain stock in appearance, (doesn't want to offend judges, ya' know:).  After first screwing down hard the intake valve inspection cap for the #1 (rear) cylinder, a punch marks the spot on the shoulder of the cap that is up (12 o'clock). He then drills/taps and screws in what looks like a hose fitting nozzle. Next, a spare  A71S breather pipe is bent (shortened, too, maybe?) in a convoluted way so that it can be fitted with an oil banjo to the hole where T29 is normally placed. Lastly, he connects the end of the pipe to the little nozzle with a short length of hose. Whether or not he drills open the oil cap like Big Sid recommends, I don't know. So far, I know of none of his tanks exploding, oil pumps failing, exhaust smoking, etc., and I have seen at least one of his machines red-lined. Oil leaks on his machines? "Nada."

Ernesto is also an aircraft mechanic and restorer, and commented that he made changes to aircraft to reduce oil on the tarmac (and the aircraft!) and this was approved by their aviation inspectors. He figured he could improve on the Vincent's breathing arrangement, also.

So far, looking at several of his machines, none leak from the breather, that I can tell. In fact, I see no leaks, anywhere, so either their owners have a handy rag at all times or he's doing effective stuff toward no leaks.  The pipe bending is definitely the only item that a bloke like me would struggle with, in doing this fix. I can see that other adaptations might work, regarding that. Anyway, this set-up appears to be a breather leak stoppage, as opposed to minimization.  Bev Bowen  9/4/07

 Oil  loss  out the dynamo drive opening  if more than mist is most likely due to the fit of  ET 164 in the back case wall allowing oil flung off the chain onto the back wall  to slip down behind this component and the wall -  after which it escapes to the outside in large quantities.  Everyone blames the apparent simplicity of  the system found to prevent leakage around the dyno shaft but this is seldom the cause.    Remove ET 164 and  straighten any dings in it, clean the surface and that of the wall all aroundwhere it goes  Seal nicely with RTV compound and  tap back into plac .  Also build up a mound around its rim with  RTV  to help it shed the  oil flowing across it.   Leave sitting 24  hours with the Dyno cover off  to harden.   Pressurized  cases are due entirely to massive ring blowby, usually caused by out of round  / buckled  liners done in  by poorly fitting  muffs.   Often the cause for this is overtorqued  maln headnuts which doom the top half to all manner of ills,  unable then to expand as designed,   causing  crushing / distortion of the cylinder assemblies,  which overwhelm the rings ablities to seal against combustion  pressures against the now out of round / no longer straight  walls.   A brief ride goes OK , but sustained speed drives up the heat and distortion  rears its  destructive head.  None of this a fault of design,  but directly due to improper assembly.  With  proper preparation of the head and cylinder joint  urfaces no  more than 30  to 32  ft. lbs.  torque is required to maintain a leak  free  joint.    This leaves a natural elasticity in the big studs that allows the alloy column  to expand as necessary   under peak engine heat  and contract upon cooling.   Sid  9/4/07

Timing chest thrust washers: While there exists very powerful endwise thrust upon followers from the pushrods being tilted off the vertical -  the camshafts get little or none, they simply spin round happy with no more than 3 to 5 thou. end float.   Thus there will be no marking of the rear wall surface.  And no noise arises from this source   Sid .  1/30/07
Generally, when restoring a vincent, the engine has been sitting for some time.  During assembly I spray the cams and followers with molybond. Here is what I do when starting up a "new" engine. Inject/pour oil down each pushrod tube, this floods the cam and follower area. Remove the ATD cover and fill the crankcase up to the the ATD opening. replace the cover. Remove the spark plugs and with the bike in gear,  push it around or run it on rollers until oil issues from the spout in the oil tank. This liberally! coats all the moving parts within the engine. Drain the sump and pour the oil into the oil tank. Put the correct amount of oil into the chaincase and
gear box. Start the engine and run it at a fast idle to warm it up.   Phelps.  12/20/06

Chronological order of  Idler Gears -  first bronze, then the forged alloy one. The idler boss was the two piece shown in the parts list, alloy with steel
pin.. The steel based one did not appear until the D`s arrived, the works having found out that the alloy ones were lacking, when the spindles worked
loose. So all those machines betweemn the bronze idler and the steel idler boss, had the ET173 fitted.  Trevor  11/29/06

Gary Robinson "105" cams: These cams have Mk II profiles but modified overlap, around 95 degrees instead of 105.  They are 'timed' by setting the inlet valve at maximum lift 105 dgrees after  TDC.  This gives a balanced overlap with the inlet opening 47 degrees BTDC  and the exhaust closing 47 degrees ATDC. Brian Hill.  8/10/06
Carillio Rods:
Mk 1,s  Had plain 1"   gudgeon pin hole . No modification needed to fit to wheels.
Mk 2`s  Also had plain 1" pin hole, but needed to be modified , by either machining the rod or the head of the mainshaft.
Mk 3`s  Has the bronzed in eye, and also need to have modifications to fit.
Trevor  3/17/06
Flywheel Alignment: It's worth taking pains to get the crank assembly nicely aligned. In my experience the smoothnes of the engine depends on this rather than balance factor. If you're mounting the assembly on centres in order to check the alignment you may find that you have to carefully scrape out the centres to bring them true with the bearing journals in order to check the alignment.. If you can mount the assembly on the journals that doesn't apply. The works instruction  sheets says - "There should be no difficulty in getting the shafts to run true within 0.002 inches total indicator reading". Unfortunately, fifty years later, this condition is not always easy to achieve. If you measure the thickness of the side plates E16 you will find that they are very rarely exactly parallel but will give you a micrometer reading which varies by a few tenths of a thou' as you go around the surface.By turning a side plate to a different position you can significantly improve the alignment. It's somewhat tedious but makes a world of difference to the result. One point worthy of caution which I've never seen in print. When you've got the engine built up and you've just finished timing the valves and you're about to finally tighten up the E80 nut holding the half time pinion on the end of the timing side mainshaft. In order to do this satisfactorily you need to stop the crank from rotating. On no account should you attempt to do this by locking the primary drive as it's possible then to displace the flywheel on the crankpin. The method I use is to hold a spare half time pinion in mesh with the half time pinion and the idler gear whilst I tighten up the nut. Dave Hills brings a piston up on the compression stroke and feeds a length of clothes line through the plug hole and locks the piston against it. Both ways work.
Roy Cross  2/27/06
Valve lift: The rockers are 1:1 that is the distance one end goes up is the distance the other end goes down. I would remove the gas tank and use a magnetic mount on the UFM to position the dial gauge over the adjusting bolt on the valve being timed and measure the ups 'n downs. You don't need to actually be on the valve itself. No fittings needed.  Mike Hebb  2/4/06
Oil Pumps: The very fastest of classic racers (92 and 95 bore OHC singles revving to 9 or 10), use plain bearing big-ends. Revs are presumably valve limited (two huge valves.....) because the limit on a needle roller big-end like mine is 8. I have no wish to find out.  Both use standard Norton oil-pumps (with a Cosworth made restrictor to the cambox for a plain bearing). A Norton oil pump delivers about 6 pints a minute compared with 1 for a Vin. Oil drag seems not to be a concern for Manx's although the top spec engines cost £27,000 plus VAT and there is a lot of money ploughed into development. (Gearbox and everything else is extra. You're probably looking at £35,000 + VAT for a complete bike.)  For comparison, the 900 Ducati Monster delivers about 5 pints per minute per 1000 rpm, so it is circulating 35 pints per minute at 7. An interesting question is whether or not Suzuki would consider the Ducati pump high or low flow. They'd probably dismiss the Vin pump as non-functional but leaking.   Tom Gaynor  12/21/05
Vincent camshafts: I am  reminded of the need to ensure maximum flow through the drilled lobe passages and the need to run a drill bit through them rather than simply relying on a blow through  with compressed air.  One finds nearly always a  build up of debree or even  material left there during the shaping and final grinding  process.  Only the careful introduction of a correctly sized drill bit will  remove this crud and these can often be found at your  local  Model  Shop . There we were pleased  to find  loose bits stocked in a wide range of sizes  - indexed in thousandths of an inch.  We were very lucky to find a  set of  Andrews  Mk.2  cams  at Coventry Spares,  examination  revealed that these absolutely unused cams were drilled  with a  54  thou. diameter hole and  even these were fouled  somewhat in 3 of the holes and indeed one lobe had not been drilled through the inner bronze  bushing  at all.  Other cams on hand in my shop showed variaions in hole size and all needing a  run through  to fully clear the drillings.  As the lobe to follower interface is under intense pressure and friction, here is one location where  rapid wear often occurs,  and thus the need for attention  to such tiny details is of paramont importance.    Another  is the two tiny drill ways in each rocker bushing  meant to feed oil to the rocker pin  and  all moving surfaces nearby  which encludes  the  followers and cams down below in the timing chest.  All depend on this same flow for their reliability and satisfactory service life.    S.M. Biberman   (5-26-05)
Valve Lifter Assy: With your timing cover off, it is just a matter of peeping in with a flashlight to see what is unshipped or deranged.  The cable and
rod must pull the levers in the timing chest together and the small ends of the levers must push up the camfollowers to open the exhaust valves, yet when the rod is not pulled, the small ends of the said levers must clear the bottoms of the camfollowers.   The mechanism is straightforward, but if not familiar with it you may need to refer to the Richardson book to get it 100% right.  Sometimes the return spring could break.  And the two levers have to be synchronized by the adjustment of the connecting link.  And there must be the right clearance twixt small ends and camfollower bottoms when the latter are on the base circles of the cams.  As someone else mentioned here the small end I'm talking about has a 3 x 5 mm roller in it to do the actual lifting, which is peened in place, and it is not unknown for this to get
knocked out if the valve lifter is operated at anything over idling rpm.

I might mention also that the valve lifter kit probably best suits the Mark 1 and 3 standard cams.  The Mark 2 BL cam has a smaller base circle to get a higher lift.  The Black Lightning with the Mark 2 cams did not usually have a valve lifter fitted, but sometimes it did.  If the valve lifter is used with Mark 2 cams it needs extra care in fitting and adjusting because of the differences mentioned.  But it always needs care in fitting any time any of the pieces and parts involved are replaced anyway.  Heck, let's face it, Everything on a Vincent needs care in fitting!  Bill H. (5-15-05)

Valve Guide Seals: Ron Kemp supplies a seal kit that works. You remove the guide lock  rings, ET122 and ET122/1 and machine the guide down flush with the
collar on the valve guide. This can be done with a piloted counterbore  cutter in a pillar drill or with a slot drill; in a milling  machine.You then fit the replacement lock rings which Ron supplies.  These have a counterbore in the bottom so that when they are screwed  down on the guide you have an annular groove to take the square  section seals provided. However, the guide rings are machined  undersize so that they can be reamed in line with the guide to provide  a bit more support for the valve. the seals can then be eased into  place and the valves and springs re-assembled. A word of caution. Take  the sharp edge off the corner of the valve stem where the larger  diameter meets the smaller one to avoid cutting the seal when the  valve is inserted. I fitted these seals to my three twins about five  or six years ago and haven't fouled up a plug since.   Roy Cross  5/14/05

The use of silicone sealant should not cause anyone cause for concern.  As with many things, misuse of the product it blamed on the product itself.  To use silicone correctly as a gasket replacement takes a bit of care. First one should clean the mating surfaces with careful use of a solvent like lacquer thiner or mineral spirits ...clean , as can be on both mating surfaces. Then spread a THIN smear of silicone sealant about the joint. Then use one's finger to remove any surplus sealant from the inside of the joint by just running the finger around the inside of the (let's say) cover to remove any surplus sealant from the inside edge. If you do this correctly, you will create a little space (on the inside) for the silicone to fill without making an inside surplus "bead". This is difficult in some of the thinner joints as those found it the timing case cover. Just make sure that all is coated with a thin smear..... meaning, about  matchbook cover thickness. The important part is to assemble the cover, with sealant, just snug enough to allow a little sealant to squeeze to the outside. Again, the cover should not be fully tight because one does not want to force OUT the sealant. With the cover just "snugged" up allow the silicone to cure and thus the thickness of this now solid material (sealant) becomes a real gasket ..... rather than stuff forced out of place due to fully tightening while "wet". I allow 24 hours to pass before fully tightening the cover. I believe one can see the general logic here, you want to have a fully cured rubber gasket to tighten upon. Yes, good results take time........ so, what's new?   P.S. :  Isn't it nice that they make grey silicone for Rapides and Black for that other thing.    Rip Tragle  ( born again Luddite) 7/24/04

Historical note: one-start, two-start oil pumps.  P.C. Vincent told us himself about 40 years ago that the two-start worm was a desperation measure on Picador development.  He had no two-start plungers so got some two-start worms made and used them with the standard one-start plunger to double the oil delivery for the Picador to keep the big-end bearings working for the prolonged (24 hour?) full-power official acceptance test.  PCV said they knew it wasn't correct, but it worked okay and the wear from the mis-matched parts was not excessive.  George Brown and others used two-start worms with one-start plungers in their racing twins in the old days.  Only in recent times did someone make two-start plungers to match the two-start worms.
I won't re-hash the question of whether double-speed pumps are necessary or desirable, but as P.E. Irving pointed out in his autobiography, all the great national and world records set by Vincents back in the golden age used one-start worms and plungers.  Bill Hoddinott 7/24/04 
Tightening the ESA nut:    Place the motor in fourth gear. Lock up both rear brakes hard  by tightening the wingnuts.  Run a wooden  broom handle through the rear wheel  - through between the spokes at rim level, with the rearstand down.  The handle lying behind the stand legs.  The object is to have the motor rotated to bring up the up against the stand legs , now the  resistance is shared by both brakes and  wooden handle and that spoke nipple.  No damage will be done if this method is
employed correctly.  I use 90 psi  air pressure driving my half inch impact driver and the proper socket, this ground flat on
its face to secure full grip on the nut.  Loc-nut grade Loc-tite on the outer half of the threads, these both cleaned of oil.  Make sure the assembly is guiding the washer home on the splines, not butting end on.  Using less than full on the power adjustor and
leaning heavily against the wrench proceed to spin it up in several short applications while watching the components embrace  and close-up against the springs pressure.  The nut will come home and slow its turning as the travel is closed up. As it comes to rest and  is seen stopping its smooth motion, fighting further movement -- stop .  If  you persist and beat against those  obvious signs to quit you can turn the mainshaft in the flywheel , sheering the Mills pin in the process.   The same process - with the handle in front of the stand legs will serve to loosen the nut.   S.M. Biberman   2/24/04 
PD 7 ESA: The bar between the sprockets can be further improved on. A piece of 1" or 1 1/4" by 1/4", 4 1/2" long. The length is not super critical. Across each end weld, braze, bronze or silver solder, neatly, a piece of 1/4" rod. Make one higher and one lower from the centre line. These bits of rod are there to fit neatly into the root of the tooth form therefore keeping the load low down on the tooth.  Phelps  2/24/04

Diecast case external features: a different font for the Vincent name on the drive side, much slimmer, clearer to read and more precise than the same on the sandcast case; no excess metal around various bolt bosses; a smoother finish to the casting without the characteristic sand-grain of a sandcasting.  Maybe some lines on the casting from the parting joints of the die, can't remember this one for sure.  Bill 8/13/03
Diecast case external features: Under the dynamo, there is a cast in depression. Bruce Metcalf  8/13/03
Die Cast Cases: Phil Irving told me himself that he drew up the improvements that were used in the diecast case before he left the firm and went back to Australia in '49, but for some reason they weren't implemented in production until years later.

For those who have never seen a diecast case, let me mention the improvements more specifically:

Better dimensional control, less weight by avoidance of surplus material.

Camplate spindle boss greatly strengthened, made a full-width boss in the gearbox ceiling.

Camplate actuating bevel boss also made more massive and continuous, although unlike the spindle boss, I never heard of any breakage on this.

More metal around the main bearings to hold onto them more reliably (the drive side roller race almost always comes loose in the early case, either from flywheels shifting out of line a little, or racing abuse).

More metal in the front end of the primary chaincase so that if the chain breaks it won't take the casting out.  Bill Hoddinot  8/13/03

First set of Die Cast Cases is reported to be #9972, although some sand cast cases carry a later serial number.
Engine Lubrication mods: When Herve Hamon visited with me he described how he used a small Honda pump located within the timing chest and driven off the big idler, sited just below the breather pinion I  think ?  This to furnish immediate oil to the cam lobes on start up. It drew its oil supply through a small pipe taken back into the scavange gully where oil is always left pooled upon stopping the motor. No more dry lobes or followers.  Keeping the valve springs nicely oil wetted will reduce a big source of rubbing friction and heat, and a move to single spring technology an even smarter move.  Flowing more oil through the upper head inner surfaces should allow a higher compression  ratio tolerated w/o bringing on detonation. The old scheme of knife edging the lower edges of the piston to skim off oil more effectively - this thrown then up beneath the crown and on the pin and bosses is still a good trick . The big end eyes can be drilled through to project oil upwards for cooling the piston underside too.  Sid  3/2/03
Oil Pump: It takes 195 revs to pass one cubic inch, therefore 54015 revs to pass one gallon. These figures now equate with Glyns in as much as one pint flows in 1.69 minutes at 4000 rpm.   So my calculations and Glyn`s are the same, 13.5 minutes at 4000 rpm or 27 minutes at 2000 to pass one gallon. So now you know why you should be taking at least 50 miles to warm up the engine. Trevor 3/2/03
I have fitted several sets of
Megacycle cams both MKI and MKII. I never have compared them in a given engine with any other cams but they seem to be comparable in performance to their Vincent counterparts (MKI and MKII). In my opinion they are superior in two ways: 1) They are definitely quieter (because of modern quieting ramps) and therefore will probably last longer and 2) they come with timing specs specified at .050" lift which is easier to obtain an accurate adjustment if necessary. I have a set of MKI's in my Touring Rapide with over 60,000 miles on them without any sign of wear. The lobe centers are slightly different than stock at 97 degrees intake and exhaust. MKI's are 30/44 and 44/30 timing specs with the MKII's at 37/51 and 51/37. Lifts are about .340 and .385" for MKI's and MKII's respectively. Just happen to be close to the source if you need more info. or would like to get a set. Dave Molloy 1/23/03
Timing Card information provided by
Megacycle for Mark II Vincent Cams:
Timing at .050" lift at valve.  Timing checked with Zero Clearance.  Cam Number 554x2 (Mark II)

                        Intake             Exhaust

Open:             37 BTC             51 BBC
Close:             51 ABC            37 ATC
Valve Lift:       .365"               .365"
Duration:        268 Deg.           268 Deg.
Lobe Center:     97 Deg.           97 Deg.
Lash (cold):     .001"-.003"      .001"-.003"

Megacycle Phone: 415- 472-3195 or FAX: 415- 472-1497.  Address: 90 Mitchell Boulevard, San Rafael, California 94903.  They have no email address.  Ask for Barbara in the sales department or for Jim Dour to answer any technical questions. George Missbach Jr. 1/23/03

Cylinder Liners/Muffs:  Only rarely have we trusted the reuse of cylinder assemblies without fully servicing them. On the vast majority the liners were seperated  from their alloy muffs. Most  finned muffs are found to be somewhat distorted and giving evidence of the crushing forces they must live with, often tilted and of unequal heights.  Large precision expanding mandrels - one each end - allow them to be held  and spun on their true centers while tops and bottoms are trued to the bore center and recut to equal heights. Then the bores, always showing high and low areas plus deposits of burnt oil - this evidence of gaps existing when running - are carefully taken out just enough to restore straight surfaces without this island effect.

The upper liner recess is recut as new. Then new liners - usually 40 thou OS pieces -  are gripped in the mandrels and the OD  is turned down with a fine cut to the desired size - 6 thou greater than the new muff bore, this just over the distance covered by its muff.  Beneath that the projecting lower portion is taken down to a firm hand press fit in its upper cylinder register mouth, and marked for that position, front or rear. After being cleaned carefully this liner is wed to its muff under the press while
nicely heated - the sleeve being cold. Allowed to cool fully under the press it is removed and examined at the upper end to ascertain that the flange is indeed fully home after cooling. If not then the heating and press is repeated to acheve that aim. The process is repeated for its mate. The drilling site and cupping / milling away of the rear thrust face for catchment is done Only after being sure that the hole will break through Beneath the oil ring land on the piston, it must not be high enough to force oil in to fill that groove on the assembled piston fitted to its rod . If not done correctly that cylinder will always run very oily - the scraper ring unable to clear away the excess.

Only a Very thin hard base gasket paper as was first used will not squeeze down loseing your torque settings. We now eliminate that gasket fitting a thin O ring lying in a shallow recess turned into the lower inner edge of the muff where it meets the liner surface.   Just a quarter inch wide smear of sealant beyond that is employed, the rest of the wide alloy faces allowed into full and intimate contact for increased thermal flow into the cases .

As to the matter of the gap between the upper faces with the head firmly sitting atop the head - after lapping as prescribed
in the Works sheets, we usually find a gap width of around 3  thou. resulting from the grain size differance, the courser used on those broader faces having removed more metal.  This will close up hard upon torqueing the head nuts as Irving designed it to do . With the bottoms of those big nuts and the washer faces smooth and flat - use a fine oil stone - and lightly oiled the procedure is to tiguten criss-cross in several small stages up to a figure of No More than 30 to 32 ft. lbs.  Leave sit overnite to settle out and repeat to that same figure . For the reasons dig out my piece called " Demon Tweak",  its in Forty Years On " and was  fully to Irvings acceptance. Simply  stated - beyond that figure removes the natural stretch needed within the
cylinder long studs, this allowing growth of the alloy column during the full heat of operation, with out distorting the muff or pulling down the cylinder head internal structure causing loss of allignment between top to bottom guides leading to valve leakage and burning, and rapid stem/guide wear.  The shop proceidure described is very time consuming and thus costly, but there is no other method of ensuring correct top half function when hot, all necessary for a fast Vincent.  S.M. Biberman  1/13/03

Cylinder Liners: I had the same feeling as Tony Maughan. I always thought (and still do) that Vincents got it wrong. The fact is that the two bores (in cases) are not split in the center and thus you cannot put even pressure around the liner! When tightening up in the manner the works favoured you simply put a depression on the liner (front right/back left) Temperature differencies are there as well between muff and cases. My muffs went on the lathe and were cleaned out to make them round again. Faces were cleaned up as well. I turned two oversize liners out of a spuncast tube (about 50 years old). Got this tip from "Mavro"  - a once famous Indian tuner who broke many records and made all parts needed for the engine himself. The spuncast tube was very strong to turn and till now does not show any wear - and cheap as well - on the local scrapyard I paid 5 USD for half a meter!  The lower part of liners was turned slightly smaller for easy fitment - just falls into the bolted up cases. After more than three years of riding and racing everything is perfect and I see no need to grip the lower part of liners. If muffs are machined correctly and everything is square and even - why should a liner turn in the muff then? There is no rotating movement - only up and down.You may add a grubscrew for your personal worries but I think this is only a point where the liner could start to crack. Hartmut  1/9/03
interference fit of liners can be affected by the material used, 6 thou is the norm for your average Vincent liner made from honeycomb, 4 thou for the muffs made from real material.  As for the fit in the case, you have to consider that when material expands, it expands from the centreline of its mass, therefore a hole will get smaller initially until the temperature gets
high enough for the hole to grow larger. So any liner gripped by the case will have the tendency to close down on the piston clearance.  Also the studs have a story to tell , and if you look at any piston that has seized, you might find that the seizure marks correspond with the studs. This would be due to the studs taking away the heat from around the hole, and not
allowing the aluminium to expand so fast at that point. All this has been found on test at the Anglo/French consortium works.
So clearance is a definite requirement between liner and case. You will notice that this will explain Toms experiences.
And if the muff /head joint is correctly ground in , how can the liner possibly turn?  Trevor  1/9/03

Cylinder Liners: From my readings when I first built my Shadow in during '79 through '81, the intention by Vincent was for the crankcase to actually grip the lower section of the liner.  The first set of liners I installed were sized to fit in this manner. In 1989, during a top-end rebuild, I went with the new (then) low-clearance pistons and a new set of Tony Maughan's liners which turned out to be an easy, almost sloppy,  slide fit into the assembled (and bolted-up) crankcase.  I was completely aghast and called Tony who stated this loose fit was intentional.  Tony explained that the grip of the crankcase actually distorted the liner, so he purposely turned the lower outer section of his liners undersize.

At that point, my concern was the amount of interference fit between the liner and my muffs which I feared was less than desirable.  With the intention of locking the liner against rotation, I got the idea to drill and tap a single hole in the rear base of each muff in which I installed a 1/4" socket (allen) screw which fit into a mating 1/4" diameter impression ground into the liner.  I just barely snugged the screw in place using blue Loctite.  So far, I don't believe the liners have turned.  Russ Williams 1/9/03

To avoid cross threading your exhaust nuts, the following should certainly assist you in re-assembly.
    1. With the exhaust nuts completely backed off, start the nut and note which fin is at say, 12:00 o'clock. Mark the fin with a felt tip. Do it again, re-start the nut and notice the same fin should be in the same place.
    2. Figure out a permanent mark on a particular fin that you will recognize next time you re-assemble the system. Even if you are by the side of the road, in the dark with a flashlight, you will Know that the fin with your little file mark in it goes at 12:00 to start the nut. Carl Hungness 12/10/02
Tapered exhaust nuts: I stretch mine over a well greased tapered thick wall tube a bit at a time until the nut is a snug fit in the
head. A heavy duty vice is all that is required.  Peter Bell  12/10/02
Primary Chain Breakage: A twenty five thou movement of the engine sprocket, would mean about 2 (two) thou of movement of the chain at the dynamo sprocket. The width of the link inside the plates is on a good quality chain .228" on
an inferior chain .234" . That difference is explained by the thinner sideplates used and the poor quality of the assembly. The width of the dynamo sprocket is 5/32" (.156" -.010) , so as you can see a lot of side clearance there. So as you can see plenty to overcome a sideways movement of two thou. BUT there is also float on the clutch sprocket, which is why there must be enough side play between the dynamo sprocket, which is in a fixed position, and the chain that can move sideways. This clearance should be checked with the chain sprocket being moved to its extreme positions, to ensure that the sprocket is central to the movement. I think that it is failure to do just that , that is the cause of many chain breakage's. Side wear on dynamo sprocket teeth have shown that to be so. But , Sid does have a problem point with the wear on the engine sprocket and the ball bearing that it abuts to. I put this down to the fact that the radius on the shaft entry is now greater than it used to be, and some bearing manufacturers use a universal inner ring that allows for the fitting of a seal, consequently the diameter of the face is smaller. Japanese manufacturers seem more guilty of this. What it means to your sprocket is that only half the available surface is used to support, and that's just not enough to stop wear occurring.  My modification is to make a new PD2 in the
form of a top hat, with the brim against the bearing, and machining off the internal boss on the sprocket. Tests have shown that this works, but the sprocket will have to be re- case hardened , to replace the case where machining has taken place.
Trevor Southwell  11/16/02
Valves: For better results the exhaust wants to be 2mm smaller in diameter, and the inlet 2-3mm larger. Around 3-4 BHP gained by doing only that. Trevor Southwell  9/12/02
Valves:  I have done extensive flow testing of Terry's big port head. As supplied:  intake flows 108cfm at 10" test pressure. 1.800" valve at .550" lift. 35mm port. After reworking:  156cfm, 1.845" valve .550" lift. 38mm port.  Exhaust started at about 85cfm with 1.670" valve at 480" lift.  After reworking:  144cfm, 1.630" valve, .480" lift. How much power do you want?  More flow, more potential HP. Small valves/high lift or big valves/low lift.   I think that Vincents theory was large valve with low lift. This allows the end pivot follower to live a little longer.  I will settle for .510" intake from .320" lobe and 1.375:1 rocker. For larger lobe I need to make stronger followers.  Race engine will have titanium valves with larger margins. Better flow. Maybe the same idea as RimFlow? I've moved the valves much closer together and have special cams made with 112 degree lobe centers.  I am worried about cam and follower wear with the spring pressure necessary to control the valve train at 7500-8000rpm. Anyone know a magic coating?   Steve  9/12/02
Valves: The titanium valve will not work unless you have a mechanical means of keeping the collar in place. For a coating try chromium nitriding, a vapour deposition process . But what's 8000 rpm going to do to your big end ?  Trevor 9/12/02
Pushrod Tube Seals: Ahhh, a Series "D", good choice! You can simply take off your petrol tank, no silly distance piece to fumble about with as on lesser Vins (B's & C's), undo your rocker caps and remove the pushrods. Now loosen the pushrod tubes and while wriggling them about, pull the old seals out of the crankcase. Go to your nearest/favorite auto supply house and get four each of O Rings that look like they will fit, determine which ones fit the best in the case and around the pushrod tube. After you have rolled one over the top of the tube and down to the crankcase, slop some silicone grease on it, replace the top nut on the pushrod tube loosely and with a blunt edge force the O ring into the crankcase, it should be a fairly tight fit and below the top of the case if it's properly installed. Do it three more times, and put everything back together. Fit another "D" breather cap if you feel so inclined or even be more radical and stick a PVC valve in the breath! er hose(s).  John  7/16/02
Pistons: It is so long since Vins were made that people tend to forget that the original C.R. was so low.   The Rapide was 6.45: 1 and the Shadow was 7.3 : 1.  The Comet was 6.8: 1 - I'm not quite sure why the Comet differed from both the Rapide and Shadow,  but pistons were made in 6.8, 7.3,  8,  9,  11,  and 13 to 1.  However,  a standard Twin has enough power for most road use.  I was very friendly with Ted Hampshire both before and after the close of the Vin manufacturing.   He always advocated the use of  7.3: 1 for road use,  saying there was no smoother or more enjoyable to drive bike than one set up in this way.   I know fuels are different today,  but here in England we have to use unleaded,  which runs hotter than leaded.    I have always built my bikes with 7.3: 1 and to this day agree with the expert opinion of Ted.   For all round road use,  i.e. torque and performance, you can't beat it.  Derek J. Peters  7/16/02
Pistons: If your bike was not vibrating badly and you don´t need to open the crankcases, check your piston weight and compare to the new pistons. If they are lighter there will be no problem (if your crank has the std factory balancing). If they are heavier you should machine the pistons to get back to the original weight of the old ones. You can remove metal everywhere but most effective is a reduction in length of the pin. The circlip grooves have to be remachined according to the pins length. The inner diameter of the pin can be opened out to 14,5 mm by grinding and the outer portion of the bore can be ground in a taper.  It is all very time consuming but well worth the effort because otherwise you will not ride the bike very much.
I got only close to the weight of my 7:3 to 1 pistons with the new 9/1! The sandcast 9/1 were heavier and as everything possible was done I was left with an overweight of 28 gr each. After installing the 28 gr heavier pistons the vibration was bad and I had to open the complete engine for rebalancing  ! Once the engine was balanced to the much better factor of 47 % the bike became smooth again and its a pleasure to rev it ! Standard Weight of 7:3 /1 diecast piston is 436 gr complete with rings and circlips.This works fine with a works balanced crank because the diecast piston is already lighter than the std Specialloid at 492 gr!  Fitting the diecasts lifts the balance factor considerably and gives you a smooth engine.  Hartmut  7/16/02
Timing case spindles: Get a good straight edge (a machinists' GOOD straightedge) and measure the depth of the faces of the area around each spindle from the timing cover mating face.  Then add the prescribed amount (0.419 to 0.424, KTB).  Turns some sleeves from whatever material you have available, and sink the spindles using these as spacers with a washer and nut on the spindle end.  I suppose one could use a standard steady plate with the spindles bolted in for alignment, but I doubt
it is that necessary.  Glen Bewley  7/6/02
Spindles: It seems like individual tubes, cut to length per the stackup of shims, cams or followers, etc. plus one clearance shim to be removed, would allow precise individual insertion.  The projection dimensions would be handy to know, but then the steady plate is pretty flexible; the hollow oil feed spindles are the critical ones.  Rip Tragle horrified The Faithful some time ago by suggesting that spindles get hammered in to a heated crankcase; of course, he was using 4340 chrome moly steel spindles that should take it.  I prefer the light tap myself.  Bruse Metcalf  7/6/02
Irving-Vincent: Infomation on production of new crankcases and complete engines.

Oil Filter: Pre-soak your filter in a jar for at least an hour before replacing it into the machine. You will be surprised just how much oil the darn thing holds not to mention how long it will take before the oil flows through it to the rest of your engine!
Store (new unused oil filters)  in a tupper ware or plastic tight container to keep moth larve out. They bore holes in wool. 3/6/02

Balancing the Vincent engine: If the crankshaft is an original unit ( by this I mean the original conrods and wheels) it should have conrods of the same forging type (there are about five different forgings used). These will weigh pretty much the same so as long as the wheels are a pair, i.e. they true up well and have the same chamfer.  You can balance the crank as a single. My method is as follows : Get the crank running dead true (checked on mainshafts with measure clocks near the flywheels and at outer ends), put it in a lathe and cut flywheels down until both run true - usually they don`t by 0.2 to 0.5 mm .With care you can hang the conrods on a rubberstrip for slow revving machining. Cover the bigend in fat before machining thus avoiding swarf entering the bigend. After turning you have dead true flywheels. Now the balance: Weigh the little ends (support flywheels on level surface, vee blocks are good), rest the conrod little ends horizontal and dead centre of your digital scales ( 0.5 grams ). Take the individual and combined weights for a good average. Add to the little end weights the total weight of both pistons, multiply by your chosen balance factor (I would suggest a minimum of 45% and depending on your average RPM,  i.e. over 3000 up to 50%), and subtract the little end weights. Put the flywheels on balancing wheels or straight edges, hang a small container with the calculated weight in, and balance. Any small out of balance moments can be corrected whilst balancing by varying your placement of balance holes one wheel to the other. I would suggest that any holes that may need drilling are done on the edge of the wheels, this way they collect no oil or debris.  And don`t forget to wash bigend out and let it dry before balancing!  I got this from Bob Dunn and it works very good!  Hartmut  2/2/02
Camshaft: Measuring lobe separation from the lifter when it is at its highest point or points?  Put a dial indicator on the valve stems or the tops of the adjuster and plot the actual lift.  This would take into account the way the cam nose contacts the follower at different points of rotation.  Then the lobe separation is measured between the high points of the lift.  Bruce Metcalf  1/28/02 
I am using a
Moto Guzzi oil filter, it fits in the same place as the original filter and you can use the standard oil filtercap, including the emergency valve.  The filter is original for V65, V50 Monza or V35 Imola, part no. is : UFI 2546500.
Just pull the attached spring off and the special oilseal out, then find a O-ring of  30  by 5mm and place it were the spring was.
I did not invent this myself, Peter Volkers told me this.    jos  1/03/01
Just don't understand why everyone is so bent on
timed breathers. A simple U tube manometer will verify how ineffective they are compared to a reed or other efficient PCV valve. My Shadow pulls negative 18 inches w.c. between 1000 and 4000rpm. The trick is a positive sealing and light acting valve. I have not been able to better the results from a carefully designed reed.
 Steve 1/03/02
Pushrod Seal: The upper seal will work better if the top face of the pushrod  tube is dead flat. The best way to get the flanged over end of the pushrod tube flat is to take the lightest of cuts over the end face in a lathe. There is no need to touch the under side of the flange as there is a danger of making the flange too thin and fragile if you do. Just remove any sharp edges with a dead smooth file whilst the tube is spinning in the lathe. The seal will now work on two machined surfaces - one in the head and the newly turned and flat tube end - ET46

Whilst the tube is in the lathe take the opportunity to polish the whole outside of the tube with  fine emery cloth, especially at the bottom end where the tube will enter the crankase seal. Its amazing how oil will creep past the finest of scratches so polish all the scratches out.  No need to worry abought altering the outside diameter of the stainless tube but worry about cleaning the lathe of all that emery dust properly!

The crankase seal is a poor design! I think a tight fitting O-ring is a better seal than the standard hydraulic seal ET104 we have always used.  I think the standard seal is distorted by the close tolerances between the crankase machine recess and the tube being too tight, thus preventing the hydraulic design seal from working as intended. These seals should not be distorted for them to work properly. It is better to use an O-ring and oil-resistant sealer around the outside just before final assembly. Apply
to the outside only and wipe smooth before the stuff dries.  If you are making new tube nuts ET127 a nice little modification
is to cut six slots instead of just four this makes it easier to get the two prongs of the K1 spanner to work in a confined area and to enable a nice snug bite on the seals to be maintained. If you can, make them in stainless and polish them. Its also a nice mod to put a thin steel washer between the top of the tube nut and the fibre washer to prevent the action of tightening the nut from tearing the washer.  Andrew Rackstraw 1/03/02

Welding Crankcases: The "B" case you saw at the Rally was missing a massive amount of metal. 1 to 1.5 inches from the entire drive side. I knew it would be impossible to avoid distortion. The case halves were bolted together and preheated to 400 to 500 F, checked with temp. crayons. Temp was maintained during welding with large gas flame. Welding was alternated
side to side and in and out. Slow cooled in fiberglass wrap it took an hour before I could touch it. Total distortion was only .035". Probably could have reduced that by peening the weld. Doing a major repair of a "C" case at this time and will try peening. I used 4043 rod . The repair piece was fashioned from 6061 and joined easily to the case. Lots of buffers in 4043. When blended the repair was invisible.  Steve Hamel  9/26/01

Excessive Valve Adjustment:  Stainless steel is an excellent material for pushrods because of its work hardening qualities.  I quote from an interview with none other than Phil Vincent, in the "Motor Cycle".  When asked why he had chosen stainless steel he replied :- "Stainless steel of certain selected alloys forms a very stiff and rigid material which possesses the excellent
quality for pushrod purposes of very rapid work hardening.  Copnsequently we are able to use very light yet stiff pushrods, which can be left in the "as-machined" condition because the ball end work hardens within the first few revolutions made by the engine."  I would suggest that a lot of (valve adjustment) problems have occurred because over the years pattern parts have
been made of the wrong grade of material.  And pushrods have been used that had damaged ball-ends before they were fitted.  Just like the bad name given to the alloy idlers because pattern parts were made of the wrong grade of alloy.  In the early fifties these problems were vitually unheard of and Vincents covered huge mileages without all the fancy parts that are now
recommended.  Pattern parts and ham fisted D.I.Y. mechanics have caused the myth of Vincent unreliability.  D.J.P.  9/13/01

Cam Follower Wear:  I think that the problem is worsened if the rider allows long warm-up periods of the motor just ticking over at a slow idle to warm the oil .  This cannot be inherently a good practice due to the speed that the camshafts are rotating. Not  too fast - but  way too Slow !  If ticking over at  800 rpm, those camshafts are turning over at only  400  revs - half
the speed of the crankshaft .  This tends to cause a juddering and inturrupted motion over the surface of  all followers and lobes leading to an oil film breakdown .  Too slowly and that wedge of oil seperating the metals at point of contact bleeds away. Where before all was a sliding motion over that film, now the pores and previously rent skins dig in to each other and rapid wear ensues.  All of this made more possible due to the slow oil pump speed and low delivery.

The morale of all this is to refrain from long periods as described.   Set a faster idle of 1600 to 1800 - or double the
earlier revs.  This advances the timing a bit so burning the pipes less as the flame retreats back into the chambers. It is even better to ride your Vincent at a gentle speed to warm all components equally and move some air over the exhaust  pipes.   The
colder weather coming should have you blocking off those air inlet spaces at the front between  fuel tank and the UFM.  This results in a quicker warm up and higher temperature.  S.M. Biberman  9/13/01

Oil Pump Removal: I made up a slide hammer type tool that I can either screw a 5/16 BSF bolt into (ET109/3) and use it to gently tap the sleeve into place, or pull  it out, plus I can use it for timing chest spindles also. You do realize the two start worm and plunger are a pair and not to be used half and half with a regular pump? There is NO advantage to using a two start pump on a road bike and I learned (the hard way) It'll just push oil out your filler cap if  you're going very fast and make a hell of a mess... John  (mercury crest)  05/29/01

Stud Removal:Trevor Southwell proferred that the stud had been chemically coated for oiltightness.  So while at NAPA
(North American Parts Association, or some such, a large parts chain here in the states) looking for the stud removal tool, I picked up some PB Blaster.  Now, if you've never used this stuff, go buy some NOW.  It is absolutely the best penetrating oil I've ever used, and very few engine builders around here would be without it.  I had given (loaned) my can to a friend, so was out.  However, I sprayed the stud, heated the lot, and applied torque to the stud remover, and out she came.  Glenn Bewley  05/24/01

Head Bolt Removal:  Don't try forcing that rear timing side head bolt too much.  It could well be held by the rear  cam-follower spindle poking into it.  If this is the case you could well do serious damage by trying to force it out.  If
there is any doubt about this, it would be wise to remove the rear cam-follower spindle before trying again.  If all the other head bolts came out without a lot of trouble, this is almost certainly your problem.    D.J.P.  05/16/01

Valve Seats: Ampco 45  works for us at a fitting interferance in the head of  1.5 thou, and the stem to guide inner bore clearance is inlets - 2 thou and exhausts -3 thou.  Be sure to make up double diameter pilots running in both top and bottom  guides to cut the seats dead concentric and true to both upper and lower guide bores. We machine up a third bore to assist with final reaming. This in the form of a top inspection cap in mild steel having a central boss that is bored to act as a 3rd     inline fixture for stability while doing all of this critical work. We cut a 3 angle cut on the seats with sharpely defined edges twix all as an aid to air flow and power.  Grinding in is barely needed for sealing when all is done to high standards.  Old and even new valves often need truing to achieve zero run-out when the valve is spun and must  be corrected for consistant valve sealing and compression readings, thus strong running and long life.  Sid  05/06/01

Engine Disassembly Organizer: When I took apart my motor last winter, I kept my cams & shims separated by putting ~5" x 1/4" dowels into a 2x4, one dowel per cam (or follower) and shim group.  I did the same with my head nuts and washers, which I have miked and mixed to be equal heights.  To have the engine studs organized, I copied the drawing from the spares list, enlarged to suit and glued it to a piece of  masonite that was drilled for the studs at the place on the motor they belong.  A couple of 2x4 blocks held it up in the air so that it wasn't too top heavy.  Bruce Metcalf  04/19/01

The easiest way to find T.D.C. is like Carl said with a plug stop screwed into the plug hole, but the most accurate way to use it is different to the way described by Carl.
    The easiest way to make a stop is to find one of the old type plugs which unscrew to take apart.  A hexagon bolt of convenient size can be pushed down through the centre of the plug and the locking ring used to retain it.
    Then having screwed the stop into the plug hole, set up a timing disc, using a tapered mandrel entered into the timing end of the crankshaft. (Note you only need remove the quill to do this)  Then gently rotate the engine forward until it is stopped by the plug stop.  Note the setting on the timing disc.  Then gently rotate the engine backwards until it once again hits the stop. Again note the setting on the timing disc.  Having then removed the plug stop, T.D.C. is exactly half way between the two readings you have taken.  It is not difficult to do each cylinder in turn in this manner.  You can then see if the theoretical settings for your 50 degree twin are accurate.  I've always found them to be fairly accurate.
    This way of doing it is absolutely foolproof and 100% accurate.  How you then time your ignition is entirely up to you, whether it be cigarette paper, light, strobe etc.  I personally favour using the information obtained to use a strobe as I use electronic ignition and the exact moment of sparking is difficult to ascertain using any other method. DJP  04/18/01
If you are not proposing to use your Vincent for speed events, then changing to
crank-pins without nuts is a waste of time and money.  Certainly people like John Renwick and Roy Robertson use this type of pin, but they use their own constructed flywheels which are much wider than standard ones.  This is possible because of the missing nut.  However, very large interference fits have to be used and special equipment is necessary to line them up.  They also use cranks which are cut away for about two thirds of the diameter.  Fitting this type of pin to standard flywheels would result in a weaker set- up than the standard one with nuts.  It is however possible to use a larger crank-pin with nuts,  which produces satisfactory results and was certainly widely used in racing before the advent of the newer designs.  If you only intend to use your Vincent for road work you would be better off with a properly balanced and lined up standard assembly.  D.J.P.  03/24/01
While I said that the amount of endplay before tightening the
engine sprocket nut did not really matter, I think that 1/8" does seem excessive. The endfloat can increase if a loose main bearing inner has worn away the bosses on the flywheel.  It is some times necessary to fit shims between the bearing inner and the flywheels to rectify this fault.  I think that after tightening the engine sprocket nut and ensuring there is no end play,  you should check the position of the conrods in relation to the bores.  They should be central and if they are not you will need to shim the drive side bearing  as described.  I am assuming that the drive side bearings have been correctly installed with the necessary circlips (ET 125) and spacer (ET19).  D.J.P. 03/24/01

I just finished a Suzuki clutch conversion a few months ago using the Overlander kit.  A few observations:

1.  Be ready to spend a few nights in front of the lathe!  Virtually all of the finish dimensions had to be cut, both on the adapters and the Suz clutch.  Took more cutting to get it to fit inside the cover.  Also neccesary to have a spare mainshaft or something around with the correct splines to use as a mandrel, as everything depends on the splines for concentricity.

2.  I am running it dry, so far.  I started out using only 3 of the six springs, but with slight slippage.  I now am using all six but with about .060 shim washers to lighten them up.  Clutch pull is light.

3.  It engages rather rapidly, within about 1/4 of the lever travel.  Takes some getting used to.  I may try oil in there to see if it softens it up any, and may change the lever ratio.  Paul Zell  03/09/01

Suzuki clutches will only run for about 500 miles DRY.  They MUST be wet. So throw away all the oil seals, and drill a few holes above and below the clutch into the primary. Trevor  03/09/01

Engine breathers: The only way that makes sense to me is a good PCV valve, the goal being negative pressure in the crank case. It is well known in the Hi Perf world that positive pressure in the crank case is not helpful. Not finding anything in the auto industry that satisfies, I decided a reed valve would provide the lightest, fastest action. Jap bikes have used them for years. Modified a four petal intake reed assembly from an old Yamaha single to fit a small cylindrical housing. Also got to thinking about oil separation and went to a lot of trouble to build a system that would allow oil mist in the vent to condense and drain back where it came from. A primary consideration was for the installation to be inconspicuous. Once installed it needed scientific testing. Contacted some friends at Aerospace Engineering at the Uof M who provided a dynamic test system using a piezo transducer, A/D interface, and laptop.This system samples 1000 times/sec. To verify data we also set up a seven foot tall U-tube water manometer. Readings were taken at 1,2,3, and 4 thousand RPM. The stock breather made minus 9 inches @ 1000, minus 3" @2000, zero @3000, and plus 3" @ 4000. The reed valve gave minus 18" @1000, minus 10" @2000, minus 19" @3000, and minus 19" @ 4000. Cannot explain the jump at 2000 RPM but over all the results are impressive! During the tests it was apparent that the c/case evacuated very quickly to a relative negative pressure, after which very little air moved through the system. This allows venting through small diameter hoses. 3/8" ID is enough. Sorry to say it but the elephant trunk is hideous and really spoils the view. Road test was next. Several runs at 75 to 100 MPH sustained and a couple of 50 to 100 mile rides proved the system. Total oil separation from the breather, no milky residue, just a few drops of clear water.
Engine is dry. Working to condense the system into a package that is easily hidden and will amaze your friends.
    Steve Hamel  02/27/01

Engine Breather: Steve - Since you were sampling at 1 kHz you should have seen some substantial  varations in crankcase pressure.  However you mention only (I assume) average pressures.  Please fill us in in the details of how crankcase pressure varies with  piston travel.  What is the availability of raw data, tables or charts?  Doug Wood  02/27/01
Engine Breather: Pressure readings are averaged. Efficiency of valve affects ratio of plus to minus. The better the seal on the up stroke, the fewer air molecules are left to be compressed on the down stroke. Interesting that at 1000 and 3000RPM the dynamic graph shows almost entirely negative during both up and down stroke. At 2000 and 4000 RPM the range is plus 12" on the down stroke to minus 32" on the up stroke. Maybe a resonance in the reed.  The raw data resides in Argentina with the engineer who built the
transducer. I'll try to get it as the graphs are four color and the yellow just won't copy or scan worth a darn.

Paul Zell, your gulp valve is an interesting device. I've had one apart and you are right in that they are a bit stiff but effective as you have proven. A U-tube manometer is simple to make and use. 8 to 10 feet of clear 1/4 or 5/16" hose stuck to a board. Half full of water and you're set. Rig an old tappet cover with a barb fitting and connect to one end of the tube. Fun to watch it react to different systems and conditions. the tube and water damp the oscillations and give a nice visual average indication of c/case pressures.

John C. it would be interesting to know if your system stays negative
all the way up the rev range.       Steve Hamel  02/27/01

Engine Breather: All I did was follow Irving's advice, except I went a bit further in increasing the sectional area by drilling out the spindle and enlarging the fitting in the crankcase.  Because of the increased chamfer and opening of the breather slot, the duration of opening was necesarily increased somewhat.  At idle a puddle of oil about 3/4" long would enter the clear breather hose; above idle it would draw back into the engine, indicating a slight negative pressure at any speed above idle.  No oil separator needed, no valve needed.  I'm happy.   It's only fair to admit that I "read the directions" only after several years of pursuing perfection through developing my own systems of PCV valves, oil separators, etc.  John Caraway  02/27/01

Colin Taylor of Lincs phone # 079800 90533 is selling Lightning Exhaust Pipes for 195  pounds, either over and under or staggered at 45 deg.Whilst they look good, the standard diameter at the port appears to be too long, this is critical to their extractive effect. It should increase in diameter just past the exhaust pipe nut. dimensions if I  remember correctly are in Tuning for Speed. You will find that you will have to jet-up, and alter the slide cut away,as well buying ear  defenders, I would also like to know if these have tested on a dynamometer.  Ken Tidswell  02/13/01

Engine Breather: The trick is to have it as the sole breather and quite large in internal bore say 3 /4 " hose on to a right angle elbow in alloy, pointing upwards at one o'clock.  A large hose releasing thusly will vent in a slow, gentle puff too low a velocity to pick-up and carry out any oil. A small bore inside diameter hose will vent in much quicker velocity blasts which will carry out oil with it. Sid  02/08/01

Engine Balance Factor: The reciprocating weight is the weight of the small end lying at rest on a scale, with the mainshaft and crank pin in a horizontal plane. This is then added to the combines weights of the Piston : Rings : Gudgeon pin and circlips.  So given all that, here`s a simple way to check out the assy.

Select the balance figure you require (X) . Therefore  X % of the total weight of the above is the figure to apply to the following experiment.
1. Place the assembled (minus piston) crank on a set of knife edges.
2. The assy. should then fall into a position that puts the crank pin directly above the mainshaft.
3. If they do not, this means that the balance weights are out of kilter. So that material will have to be removed until the aforementioned state is obtained.
4. Then add the weight of the balance factor ( X %) to the small end.

4. Then add the weight of the balance factor ( X % - the weight of the small
end) to the small end. (note: correction in next comment)
5. Roll crank along knife edges.
6. The crank should then stop in any position , no matter where the crank pin is.
7. If the crank pin falls to the bottom or rises to the top , every time time it settles , add some plasticine to the periphery of the wheel until it can stop anywhere. The weight of the plasticine gives you a good guide of the material either to be removed or added.  Derek Peters  02/07/01

4. Then add the weight of the balance factor ( X % - the weight of the small end) to the small end.

So imagine we want 35%    and the total weight of the end plus piston etc. is  21 ounces (example only), and the small end( reciprocating weight ) is 7 ounces,  the weight to be applied would have to be 35% of 21 ozs == 7.35 ....       Now subtract the weight of the small end.    .35 ozs  would be the weight required for the experiment. If we apply a 55%  balance figure the weight would have to be 4.55 ozs. These are imaginary figures.  And all for a static balance.  Trevor  02/07/01

Opening up Ports:  The rear head will open out easily to 32mm being careful not to break into the lower spring well.  Favor more removal elsewhere away from that thin spot.  Front heads will allow nearer to 1 3/8" and this size was favored by Amals when I  asked
them years ago, and was what We aimed for even with our 2" inlet valves in our Big Port Works heads. Too large a port will lose velocity, and the real restriction is the low lift anyway.  Flow can be boosted by releaving around the back-side of the  inlets, involving the liner flange and head metal in that near area.   Sid Biberman  02/05/01

Sid's Hop-up Comments on the Cylinder and Piston Group:  Each part must be blueprinted and each pair made equal in all important dimensions. Before the cylinder liners are fitted to the muffs, ensure both muffs are the same height, top and bottom parallel, and at right angles to the central bore.  Prep the new oversize liners so their outer faces and their freshly bored and honed inside walls are both dead straight and parallel.  The new outside liner faces offer nicely finished surfaces for a  .006" tight press fit in the cylinder muffs.  The top recess in both muffs should be prepared with the same precise eye. The liners should be properly  inserted into the muffs and held secure until cooled.   If any gap is allowed under the liner flange, the liner will later drop and spoil the lapped joint.  The oil feed to each rear piston thrust face must be correctly sited to emerge below the lowest ring groove. If the oil feed emerges into the lowest ring groove, it will detrimentally fill the groove with oil during engine running.

All of the above efforts have been directed at  maximum rejection of heat and maintanance of good ring seal during severe use, all paramount in a racing motor where one expects any chance of winning.  Of equal importance is the proper fitting of the piston to bore and we would  - even with modern silicone alloys - prefer a skirt clearance in a Vincent on the order of  004" rather than risk some picking up or outright seizure.  My old Rattler ran its old Specialloids at no less than .0065"  which had   grown a full thou. after the first run at the lights.  These were 12.5:1 compression ratio.

Serious power needs high combustion chamber heat and tight crown / head interface for any real squish effect. Prior to running the engine, check with clay the actual seperation distances and all relationships between components. Check again after the initial running and later again after the first race when youth and anger makes fools of us all. Repeated examination shows how clearances narrow as the rods fling and valves float  leaving telltail marks the wise tuner had best keep up with, removing  metal whereever evidence is left behind.

Vincents run long and full bore often show scuffing around the piston pin hole on both sides. The scuffs are signs of growth in width across that plane and should be eased by carefull removal of metal in the affected areas.  Pay attention to any valve contact of the edges and surface of the cutaway relief in the piston crown.  Contact in this area may cause serious damage during high-rev valve float periods,  especially where bigger valves and higher lift cams are employed.  Heavier and broader inlet valves bring on float far easier and must be watched as springs weaken.  Burnt and abused exhaust valves can show melting away at their edges from operating at elevated temperatures.          Sid Biberman  02/01/01

Reducing the weight of your Flywheels:  Imagine the completely assembled fly-wheel /rods assembly sitting on bench in front of you, its mainshafts horozontal - left to right - with both rods lying down sloping towards and resting on the bench.  To each side of the rods one faces the edges of the wheels.  With a 6 inch machinest ruler and a felt tip marker {fine point} you  draw a mark across both edges the width of those wheels.  Remove 25 percent of each marked line, this to be off the edges nearest the rods, ie. towards the center of the assembly.  That clean portion of the edge of each wheel will remain untouched during the removal process being needed still as the surface from which all oil is still to be scraped. The remainder of the  marked surface, 75  percent of the original width is to be turned off on an angle outwards towards the outer face of each wheel.  Examine the surface up the side and find a little drilled hole - must be a Works original locating index / fixture point.       This is used as the stopping point for your cut,  and duplicated on both sides. The weight of metal removed in this area does NOT affect the balance yet is a considerable decrease in mass/inertia allowing the assembly to be spun up far quicker consuming far less torque power in the process. Elapsed time over the quarter mile will take a big cut and as a result the speed through the lights can be far higher.  S.M. Biberman  02/01/01 
click for slightly larger image of Vincent Flywheel
Comment on Sid's Flywheel Mod:  On a twin flywheel , when one machines a chamfer as you describe. You will remove more material from the balance weight side, so I think the balance factor will be altered. On a Comet this does not happen, the wheel being parallel across its diameter. Trevor Southwell  01/02/01
Dipsticks: There's 80 on your Vincent that will do the job, just cut a spoke to the length you require.  The length you require is only to be determined with the G2 cover off. With the layshaft gears in position, pop in the dipstick and mark to suit. Ensure you know where the oil level is to be . I have it so that the largest gear is dipping into the oil at rest, by about 3/16 inch.  That way you will know that it is doing its job. Any old dipstick is not the way to go. There are tooo many variables for there to be a standard dipstick, that's why they are made adjustable. So adjust the one you already have. But if you really do need another, you must have a broken spoke laying that you can make a new one from.    Trevor Southwell  02/01/01

Half-time Pinion/ ESA springs: The system Irving chose which allows for fine lash adjustment between big idler and the cam gears and half time pinion is   another cost-be-damned example of his design ethics. By placing the big idler spindle in a movable base allowing it's center to be moved upwards and in an arc, it's lash with the two cam pinions can be set to fine limits. The altered lash between the bottom driving pinion can then be catered to by providing a range of these pinions having a difference in their manufacture of  9
choices, both in larger and smaller increments, by one thousands large or smaller gears. Thats 9 up and 9 down . This is an
expensive undertaking for the Maker to accept as his responsibility but of  massive assistance to the owner wanting high performance and a quieter timing chest. Happily  stateside Coventry Spares both stocks most of the alternate sizes and
assists the owner as best he can select the best pinion for his motor. Were you aware that the Honda 4  cy.  K bike of  '69 through '77 offered only the single std. size crankshaft bearing shells ?  Scratch or score a crank journal and you were out of luck. Order a new crankshaft !  Lots of  displeased owners !

If our ESA assemblies are fitted and done-up carefully, even the B/C units function well and beautifully for many, many thousands of miles.  Only recently have we spotted the reason for broken springs in some examples, actually 2 reasons.  # 1:  Many times the depth of each spring hole in PD3 /2 varies enough to cause a coil-bound condition in a number of those pocketing holes. All must be checked  for drilled depth and the shorter ones drilled deeper. Also, it is wise to inspect the mating together for least free to and fro unchecked movement between the two cam elements, the PD 3/2  and the lobes on the drive sprocket .  Each of the alternative mating positions is tried - pressed together firmly - and the outer element turned in both directions seeking that choice where there is little or no outward thrust - uncontrolled by the spring pressure.  Free movement or coasting will cause rapid cam wear and noise, roughness at town speeds and also broken springs. The springs are to be  each greased and  popped into its mating depression in PD 5 during assembly.  Removable or Blue loctite allows later service  w/o severely damaging the hex on PD 7 and a good air driven impact wrench -1/2 in. drive and a solid socket is the way to insure both fully home assembly and later removal with ease.

Assembled to these standards will insure no spring breakage and long, smooth, and slick functioning. The Series D pattern is
somewhat better with more springs, thicker outer plate and a locking eared washer, all of which is great yet the earlier faults       need be attended to for greatest advantage.

A word of warning: The  big impact wrench driven by 90 to100 PSI air in your tank delivers serious twist and can easily cause problems -as well as work miracles !  The ESA is carried on the drive side main shaft which is held tightly within the flywheel by  its interferance fit as well as a Mills pin,  Irving's term for a rather soft grooved sheer-pin as long used to secure the propeller blade to its driving shaft on an outboard motor. Strike a rock and the pin is cut across and through-saving the Prop but often having one paddle home. My warning -- when using the tools described be very wary when turning on the nut PD 7.

Reduce the air flow approx. 50 percent,  then lean into the wrench while listening /observing and being sharply aware that the nut spins up smoothly till it comes to a gradual stop - ceases to rotate - indicating all  pieces are bottomed out against each other.  Don't bang away at it any more !  Dead home solid is achieved, and no more torque is to be applied lest you spin the shaft in its wheel - sheering that pin !   If a couple of drops of med. loctite has been spread round the threads which were first made clean of oil, then All is Secure. Assembly  is greatly eased by sliding out towards you the splined sleeve PD4 allowing all components to go home, especially disc PD5 must accept those splnes on PD4 .  Sid  Biberman  01/17/01

If you have a mill it is relatively easy to check the bearing alignment of a set of cases.  Using the timing chest face as your datum, clamp the timing side half down onto the mill table.  Then having mounted a dial indicator in the mill spindle you need to clock both timing side bearing housing faces to centralise the spindle and ensure that the two bearing housings are concentric and in line.  You may have to pack up the timing case face to attain this situation if there is any damage to the timing chest face.  You then clamp the mill table and place the drive side crankcase half onto the lower case using the dowels to locate it.  You then clock both bearing housings in the top case half and ideally they should both be in line and concentic to the spindle.  It is also just as important to traverse the dial indicator up and down the muff clamping faces to ensure that your barrels are going to be square to the crank shaft.  If everything is not true to within about .0005" it would pay to consider having the bearing housings rebored and bushed with aluminium bronze.  Derek Peters  12/18/00
If you are not proposing to use your Vincent for speed events, then changing to
crank-pins without nuts is a waste of time and money.  Certainly people like John Renwick and Roy Robertson use this type of pin, but they use their own constructed flywheels which are much wider than standard ones.  This is possible because of the missing nut.  However, very large interference fits have to be used and special equipment is necessary to line them up.  They also use cranks which are cut away for about two thirds of the diameter.  Fitting this type of pin to standard flywheels would result in a weaker set- up than the standard one with nuts.  It is however possible to use a larger crank-pin with nuts,  which produces satisfactory results and was certainly widely used in racing before the advent of the newer designs.  If you only intend to use your Vincent for road work you would be better off with a properly balanced and lined up standard assembly.  Derek Peters  12/18/00
Replacing parts:  Like the surgeon's inciscion, there is a liability with each change. A main bearing outer race, when removed always leaves a looser fit for the next bearing. A crankpin, once removed will soon require an OS pin and another machining operation to bring it (hopefully) within tolerance.Valve seats removed for new seats seem to be more likely to drop their seats in the future. Do it cause you really gotta do it. Sometimes its well enough left alone.  Somer Hooker  12/05/00

Valve Guides: We  make our own lower guides from a very hard and dense wrought bronze in modern usage called    Ampco  45 .   Thus we can clean up the bore in a heavily worn head and produce an oversize OD guide giving the exact fit  desired. While at it we cut the groove for the Viton O ring for oil control down the stem , this positioned just below the     flange for greater strength during insertion. We prefer this location rather than set into the bottom side of the lock-ring  .

Alignment run-out often sees the threaded ring off to one side so that the fragile O ring is then off center to the stem. Many valves seen here both used and new when checked are bent quite a bit, and even show poor quality manufacture in that
there is visable runout of valve head to its stem, thus affecting the concentricity between seating area and it's stem, none of which is good for consistant sealing and performance.  Poor service to valve and seat rings will result in blurred and rounded seat/valve faces,  which reduces efficient breathing and power.  We do a 3 angle treatment actually cutting with 3 seperate  cutters set at 3 different angles. The sharply defined edges between each giving a precisely defined seat and width.  The sharp edges contribute to much greater flow across the sealing surface when the mating face of the valve is treated in a similar fashion. The greater the flow, the greater the volumetric efficiency.

None of the above is possible without proper piloting on double diameter pilots riding in both top and bottom guides to assure
positioning of the cutters. We go even one step further by adding a third support.  This a precision steel cap modeled on a  inspection cap but carrying another central boss in excess of one quarter inch thick bored to align with the other two guides  below. Each top guide is selectively positioned for free stem movement and then punch-marked to allow it to be assembled later where earlier it was best located. All of this done to ensure consistant sealing at each valve as well as contrubuting to high power and long life.       Sid Biberman  12/05/00

Rocker Arm Facing: Place a pad of abrasive on the collar, use double sided tape. Assemble the rocker and fit locating screw. Rotate valve easing it up and down at the same time, until you have ground down the ears on the rocker to an even
shape on both. You will find that the resultant curve on the faces is almost flat. So why the big curve on the face from new I do not know.  They tend to dig into the collar and indent.   Trevor  12/05/00

Con-Rods: The most efficient and least damaging method of  removing chrome plating is to have a competent Plater reverse the process. Afterwards you should heat soak the rods in an oven for 4 hours at 350 to 375 degrees F. Re-polish along the flanks and around  both eyes, especially where they blend in to the flanks . I would suggest they be Magnifluxed, and finally shot-peened at a local  Hot-Rod engine builder, the eyes blanked off with steel discs to eliminate exposure to their ID's .   We  often see tiny
cracks rediating outwards around the edges of the bigend eyes -- usually where a caged  roller bearing has been used . These  tiny beginning cracks dont seem to grow longer in further use, nor cause failure.  Recently we have used several pairs of  Terry Prince's lovely con-rods and they appear superbly designed and manufactured,  and the most identical of all yet examined.
Sid Biberman  11/26/00

To get rid of Hydrogen embrittlement, soak the plated item in an oil bath which is maintained at 177 degs. John 11/26/00

Distorted Con Rods: Turn your motor over with the heads off . This will show if the piston "walks"  to one side (left or right), easy to see by eye . Arthur Farrow  11/26/00

The weight of a freshly completedVincent engine is 199  lbs - Including the magneto and Miller generator as well as pair of carbs and inlet manifolds. Simply weigh those items and subtract from the stated total . Sid Biberman  11/22/00

Wear on big-ends: These results seem to be based on experience in more modern times when caged roller bearings have been used  and after much work has been carried out over the years since our machines were made. Undoubtedly the treatment meted out to Vincents over the years have resulted in very false impressions being gained in the aftermath of very poor maintenance.  Back in 1951 Tony Rose carried out  the 100000 mile test of a standard Black Shadow and the wear on the big-ends, when finally stripped, was extremely small.  In fact the big-end outer rings wear was a maximum of .0004 inch and the crankpin roller tracks maximum wear was.0003 inch while the rollers were so little worn that no comment was passed on them.  As far as the Works were concerned the big-end was just nicely run in.  The things to be noted about this are that the engine was standard and the oil (Filtrate with Colloidal Graphite) was changed every 1000 miles.  Due to owners wanting to rev their machines the caged big end has now become the main one in use.  This does undoubtedly not  have the life of the crowded roller big end used at low revs, but is much safer if you drive your machine fast.  However, even with this type of big end the advice of Phil Vincent given to Tony at the start of his test stands good.  He was quite happy  the engine would do the 100000 miles without needing major replacement as long as the revs were kept down to 5000 and the oil was changed every 1000 miles.  There are not many owners who can say they have any experience of this kind of mileage, but one thing I would certainly not do is strip down a big-end at 30000 miles to fit new rollers to worn components.  Only if you are prepared to hone out the big-end outer bush and grind the crank pin before fitting oversized rollers is this recommended engineering practice.  And if a big-end is sufficiently worn for this to be necessary then it is time to fit a new bearing. 
Can Aircraft Gas be used in Vincents:  Some years ago John Bradshaw? wrote an article in MPH re. Burnt Ex valves in his vintage aircraft - A Sea Fury powered by a Bristol Centaurus, I believe. His information was that leaded fuel does infact burn more slowly and was still burning when the Ex valve started to open, so burnt valves. The advice he was given was to run this engine on 87 octain aviation fuel. This he did and no more problems. This is confirmed by the fact that at a French Rally held at La Fait Alais all the vintage aircraft bore the legend " 87 Octain only" on their engine cowlings. Wm. Clive Richards  11/22/00

I wondered a while back how in the world Mr. Higgins' fix for head warpage, which involved shims under the nuts (as read) on the heads would help.  Easy enough, it occurred to me the other day, and was confirmed by the man himself today.  The shims are between the head and muff, taking up the space normally left when doing the narrow face/broad face lapping in of the surfaces.  Shims of a thou or a thou and a half, held by both the head and the liner flange nipping down on them.
Glenn Bewley  11/22/00

At about 40,000 miles the rollers in your big end, if you`ve looked after it and warmed it up before thrashing, will be half a thou under. The pin and eye should still be OK. But then it starts to go downhill faster.  Sure you can make it go on longer, but the final wreckage is a lot greater, with having to replace everything. So tear down after 40,000 and re-roller, and this gives you a good chance to make sure all is OK elsewhere.  Trevor Southwell 11/21/00

Valve Guide Installation:
1  Put head on fixture at the correct angle for the valve, using the four counterbored locating holes, as was originally used.
2 Clock in upper guide register.
3 Bore out for valve guide. And maybe reclaim the lockring thread if its buggered.
4 Heat up and fit new guide, and seats if you are doing these as well.
5 Replace on fixture, CHECK that the upper guide register in is the same place. And I will tell you now, that it will NOT be.
6  Bore out the guide to its required size.
7 Machine the upper guide recess to ensure that the face is square to the guide. If necessary you might have to oversize the upper guide if the the recess is out of round.
8 Refit lockring, heat up and tighten.

Some comments.
Every time you heat up a head , and recheck it on the fixture . It never comes back the same. It`s walking ALL the time. I consider that this is also happening in use, especially the front cylinder being the frame. What with the honeycomb muffs and all that.  I think that this is one of the reasons for the front push rods always (nearly) wanting adjustment. A big problem nowadays with heads is that over the years they have been got at , by the go faster, I must make the holes larger, rider. This person believes he can make the plot more efficient, when in fact he is destroying the original design. Valve guides no longer have the supporting material around the part where the guide sticks out into the port, so that when you place a guide in place, on cooling it will tilt away from where it should be. SO NEVER try to use a guide that is a finished size. NO CHANCE.

 I have found out that the face of the upper guide is not always true with guide, especially front exhausts.  Doing it this way could lead to the seats having to be miles out to keep in line. So I now ignore that face and machine it last, this way I now know where it is.  My methods have evolved over the years, some 300 or more heads down the road.

PS. I have never found two heads the same.  Exhaust ports as much as a quarter on an inch out of position, varying in depth by 3/16 " . However did you expect exhaust pipes to fit? Valve guides anywhere but in the correct position , at least to the factory
drawing.  The least said about rocker tunnels, the better.

Trevor Southwell  11/13/00

Tightening the rocker feed bolts. If you do this with all the valve gear in place you can finger tighten the rocker feed bolts, and then roll over the engine so that the bush is under load, that is pushing it against the underside of the rocker tunnel. then
when you tighten the feed bolt you are assured everything is where it should be.  Robert Watson 11/13/00

Erratic Compression: have come across these symptoms when an ET35 collar is moving up and down on the valve stem and occasionall jamming in the up position.  To find out the only way would be to lift the head.  However I think it is far more likely that you have a valve sticking  in it's guide and this is much easier to solve.  Get some upper cylinder lubricant  (e.g. Redex or Marvel Mystery Oil) in a pressure can and if you can start the engine squirt the mixture straight in to the carb mouth while it's running.  If you can't start it then squirt the lubricant through the plug hole and carb whilst kicking the engine over manually.  Once you break up the gum which is jamming the valve all should be O.K.  If this solves your problem make a habit of including a small amount of upper cylinder lubricant in your petrol to prevent a reoccurrence.  Derek Peters    11/09/00
Erratic Compression:  With pipes and carb. removed  -- and with a length of rubber hose - each in turn listen with one end  held at each exposed port . With sparkplug in place slowly listen - while the motor is slowly turned over. You WILL hear the   air rushing past the leaking valve at one or the other, ie. at inlet manifold and then the exhaust port .  My guess?  One of two things,--  #1 A chunk of  soft carbon has been caught  betwix one or the other valve  and seat , or --#2  One valve has suffered stem  to guide scouring / picking -up{too  tight  clearance }.  Probably  the  exhaust , and at its lower portion .  My  suspicion is #  1 . When the hiss is pinned down try  to soften the clump of carbon by spraying through noisy port a hefty squirt of  WD-40, several  long bursts through the port aiming at the seat area and  trying to cover the entire seat- ring .  Let  it sit and  soak one hour .  Now with that length of hose on your air pressure line and holding the hose into first the plug hole --blow short - repeated blasts  while the motor is kicked over.  Next  blow  through inlet manifold - hose shoved in right against the valve back-side .  While blasting air spin over the motor then do the same deeply up the exhaust  port - while spinning over the motor .  If  I'm correct - there is a good chance  the crud will  be blown  away . Replace plug  and  kick over. With luck  - and if I'm  correct - compression will be  restored .  S.M. Biberman   11/09/00
I had a bad time
sealing the rear intake push rod seal on the rapide (Mr Woolly Mammoth) despite good braething and no crankcase pressure.  I made alloy rings with internal o-ring grooves and .000 fit and locktite.  That did it. You must make each to fit as pushrod tube diameters are all over the country for OD. And when you dismantle keep track of each, as you should do with the pushrods and adjusters, as they have all "worn" in together.    Robert  11/09/00

Just a Quick fix for lower pushrod seal carefully dig out the old seal, degrease well and fill with a bead of black RTV, ie Dow Corning 732 number 110311 Black, if you do it carefuly it looks just like the real seal and it works.   Roger Lord 11/09/00

Timing your Vincent using Rod Bearing Inserts: When you are running a highly modified motor (e.g. with nitro) , you don't exactly have an owners manual to time in the motor. It will change throughout the day anyway. If your motor is too advanced, then the top part of the (rod) insert will begin to show more wear as it is fighting the detonation or "spark knock". I actually learned this from Dave Matson, who uses the same technique but only at the end of the year. Later when I saw them pulling the inserts out of motors ,I realized what they were doing. If the bearings are the same on both sides,your timing is spot on. If the bearing is wearing on the bottom, its too far retarded.    Somer Hooker  11/05/00
Timing: As a nitro burner needs ignition advance ranging from 54 to 60 degrees before TDC to acheve best results,  a gas burner street motor needs 38 to 39 degrees and a  Methanol  motor  less at  34 to 36  degrees to function at optimum . Thus retarded timing on the (Dave Matson) Bonneviile  bike is retarded at  48 to 52 degrees.  Sid Biberman   11/05/00

Engine Gaskets:While attending the Arkansas National meet a few summers back, I spied a lovely restored Black Shadow that had a very fine copper line separating the primary cover from its attachment, and another on the timing chest. I met the restorer, a meticilous man named Dick Busby who also said, "Hell, I quit using gaskets a long time ago. I use "Permatex Ultra Cooper."

Further research among my racing engine builder friends found some utilizing Hylomar, but the best seemed to like the very small tubed, and expensive anerobic Loctite...very, very sticky.     Consequently I bought the Loctite and among all the leaks I have had on my Shadow, none have come from utilizing the silicone based materials....and I have purchased no gaskets since.
Locktite 518 is very sticky, tends to stay where applied, and merits consideration.  Carl Hungness  11/03/00

After years of trying we finally sealed a friends DBD34 to oil-tightness by using Gaskacinch, which is WONDERFUL gasket cement.  And worth the price of admission just for their really cute "mascot" or whatever, which is an illustration of a young lady which looks as if it should come right off of the nose of a B24.  Of course, I am a huge fan of Hylomar as well, when there is no gasket, and copperkote on copper gaskets.
   Glenn Bewley  10/4/00

Location of Oil Holes on Cam Spindles: Oil holes in any situation should always be on the non-load side (opposite the thrust forces). So point them at your main bearings.  If they were on the load side, the pressure would keep the hole shut. So some to avoid this, make the hole into a slot.  This in turn is a tool to wear away the bush.   Trevor  9/29/00

Cam Spindle Oil Holes: I think the fact that the Vincent uses a low pressure oiling system makes the location unimportant.  This is backed up by "Vincent-H.R.D. motorcycles" published in the "Motor Cycling" Maintenance Series with help given by Vincent Engineers (Stevenage) Ltd.  I quote "Camshafts are mounted similarly to the followers except that the two spindles are hollow and have oil holes, the disposition of which is unimportant".

There is no thrust against the oil hole in the cam spindle for it feeds the oil between the two bushes at each end of the cam shaft.  So I maintain that it doesn't matter one jot where the oil holes are located around the circumference.

Correction:  I completely forgot the second oil hole under the inboard bush.  Still with a good supply of oil into the centre of the shaft, I don't think it would cause great problems wherever the holes were located.  However I'm inclined to agree with Sid that it would be better to keep them away from the top position.  DJ Peters  9/29/00

Lubrication:  ...  the shearing action of a gearbox  is not good for multiple "weight" synthetics, which achieve their viscosity range by use of polymers (extended molecular strings).  BTW in this regard, for any engine, it is best to use a multi-grade synthetic with
the narrowest possible range--that is, a 20W-40 is likely to be longer lasting than a 5W-40.  There is also an extensive body of opinion about whether synthetics are the ticket for low pressure roller bearing engines (did someone say British bikes--
do I hear Vincent?).  I offer no opinion on that.  I'm interested that Honda sells asynthetic for its car trannies (MTF) -- and that it is very low viscosity as well.

BTW I think the 90W designation for gear lube isn't to signify that level of viscosity, but to keep you from using it in your engine.  Its viscosity is probably more like 50W. In both cars asnd shaftdrive bikes the differential fluid recommended is 90W mineral oil, and obviously its primary function there is to deal with shearing and high load bearing forces without regular, or at least frequent, changes.

As to the recommended viscosity for vintage Brit gearboxes--I think all that matters is the quality of the gearbox seals.  If you've got felt seals in a trannie that's meant for a mix of grease and oil (if not grease alone), it would seem that a lubricant with low viscosity like that recommended for Honda cars (my previous message) will find its way out to decorate other parts of the machine--or to the clutch or primary chaincase.

I still believe as a general theory that it's more important to change oil frequently than it is to use any particular viscosity or "brand" of oil, or oil from a particular source, be it beans, minerals or the laboratory.  I have a prejudice only against high sulphur content oils, because of corrosive damage I've observed as a necessary effect of cooldown cycles.

john caraway  8/00

Gearbox-graded oils EP80/90etc, have better gear meshing breakdown resistance, so the molecules stay in grade longer, providing the correct lubrication for the gears.  20/50 is thinner, and thus has more "fling", so lubricates more of the gears - but goes out of grade quicker due to the meshing of gears... I'd suspect it's best to leave each in the environment it was designed

Vincents:- Well, I use EP grades for the gearbox, varying dependant season, and straight GP50 for the engine -  Tigger Aldus  8/00

I believe the thread size for a (bottoming) die that will re-cut the threads  in my Vincent Series "C" Twin Head  is 1  7/8" x 20 TPI, ...Whitworth..I think it has a 55 thread degree angle..and I believe the American counterpart has a 60 degree angle, but I have also been told that the American die will work.
I was once in discussion with Big Phil on this business of the
stripping of exhaust threads and he made an interesting comment.  He said that it was strange that the exhaust nuts seemed to get a taper on them after some time and they were not tapered when new, he said "why not heat the nuts and push them over a taper mandrel and restore them back to
the proper un - tapered shape".

I have never had to resort to doing this but it does make a bit of sense when you consider the heat the nuts are working in and the compression they are under and the relative thin wall of the nuts.

I have an exhaust thread bottoming Tap, I bought the tap from a tool company in Hackensack NJ phone 1-800-342-8665 called 'Tool Importers' should you find their email address would you forward it to me - thanks

Andrew Rackstraw

The main experiment  under test was  the running of a crank-shaft balance factor of  35 degrees rather than the 46  degrees commonly employed since Paul  Richerdson's  book apparently led us up a fools path some 50 years ago !    I met  Paul in  53  at the Works and dearly liked  him --  but he simply got his figures wrong !   Phil Irving clearly stated the correct balance figure in two of his books as being  35, not   46.  Marty Dickerson  long ago got the real skinny on  this from the Master himself .  In a real fury of anger Phil revealed that Paul had blundered  and got it wrong.   At speeds up to 60 the bars  feel as if they are not bolted to the bike at all - but rather lying on your kitchen  table!   From  60  up to 90 there are NO vibration  periods, only a mild feeling of being part of the motorcycle, this gently increasing as speed mounts. We were careful to blue-print / equalize  all recriprocating  component weights and the flywheel run-out was held  to about 1/2  thou. total, and pinned to  prevent shifting .
Sid Biberman  8/06/00

I have had some experience with the kickstarter problems myself, as well as having researched the malady as I too nearly fractured a knee shortly after buying my bike.  Yes, the G48 spring should be doubled, another spring simply wound into the first one..You will gain a more positive engagement with two springs, and they have been known to slip, thereby causing the kickstarter to slam the rider's leg into the ground.

The sticking is yet another problem, and happens at the top of the kickstarter's travel.. The quadrant starts to engage with the ratchet gear and actually winds up "on end of a tooth" and will not go past the end of the tooth to allow the quadrant to engage the ratchet gear fully. It has been said to "file or eliminate the first gear on the quadrant" to allow it to move freely into the ratchet gear, but my experience has shown me that this is really not a great fix.I did not successfully file and remove the proper amounht of material to insure me of no sticking at all times.

Rather, I simply do not allow the kickstarter to go fully back to the top position. I "set" the kickstarter at about one tooth below the top of the is a pretty simple operation actually. If you happen to allow the kickstarter to go back to the top, rather than approximately one tooth down, simply pull in the clutch lever, move the kickstarter down just a touch, and you will make sure you are engaged into the quadrant. In other words, don't kick the bike with the kickstarter absolutely at the top of the kickstarter's travel.

I have had the kickstarter and ratchet gears working so sweetly that it was possible to allow the kickstarter to go all the way to the top, however, when it might stick that once in 50 times is enough to frustrate you, so I just "go one tooth down" and I never have sticking problems.

As noted when discussing this problem previously, having the kickstarter slip can very easily mean a fractured knee. This is a real serious mechanical consideration on your Vincent, so if you have not renewed the  G 48 spring in mention in many years, it is (in my estimation) a MUST to do so, and please add that second spring.          Carl Hungness  7/19/00

One way to extend the life of the exhaust lifter mechanism is to obtain a kill button type magneto points cover, and a Miller grounding type horn button.  Use of a kill button to stop one's motor will greatly extend the life of the exhaust lifter mechanism.  Also, according to Sid it is important to dial in enough slack and he recommends that the lever only begin to engage after you have pulled it in half way.  Matthew Biberman  7/18/00

Valve Lifter Mechanism:  I do not subscribe to the notion that kicking the bike without the compression release will strip the splines to your noted, I have kicked my bike for about nine years now with no spline wear noticeable. (While speaking of spline wear, it is a GREAT idea to drill the kickstart spline and tap so you can run a bolt and washer up to the kickstarter itself..I used to have trouble with the kickstarter working its way off the spline until I performed this simple modification).

    If I were your neighbor I'd take off the timing cover first thing...actually just removing the cover won't do much good. You also have to remove the steady plate and all of the attendant gears that go along with it.     If you have not performed this operation previously (and lined up all the timing marks) be cautioned the Vincent has a "hunting tooth" and you may well turn the engine over several dozen times before everything lines up. If you need further instruction on how to perform the operation, I'm sure there are many who will assist you (myself included).

    Adjusting the mechanism is no easy task either. I believe you are supposed to have about 0.015 clearance between the roller and the lifter, but getting in to measure it is a task for the journeyman. I managed to adjust mine with approximately 3/8" slack before the mechanism started to move, and I had plenty of cable left, and I was able to see the mechanism working perfectly, so I put it back together and she now works a treat.

    As far as having the mechanism leak, you will find numerous cures in the "40 Years On" book and I just completed one that utilizes a valve seal out of a Triumph. I had to make a new outer tube, but the effort was REALLY worth the if you do tear the thing apart, NOW is the time to cure the leak..and it will leak..and you will have an oily rear wheel.
    John Healy from Coventry led me through the valve seal fix as did Rip Tragle as well..I had it explained to me twice to make sure I knew what I was doing. You are playing with one of the real Vincent bugaboos here, in my estimation, and it is one to be considered very seriously for I know what the knee damage can be.

    At the same time I would almost Demand that your friend replace the G48 spring with TWO G48 springs, interwound within one another. If he is on an old bike, the G 48 is probably worn badly and the result will be a slipped kickstarter which can (easily) result in a fractured knee..fractured as in bloody. I thought I had discovered a real fix by putting in two G 48's until I discoverd that some of the journeyman mechanics such as Dick Busby have been doing so for years. It will take only minutes to replace the springs. If he has never experienced a slipped kickstarter he is in for the most rude awakening of his life.

My best, Carl Hungness  7/18/00

Valve Lifter Mechanism:What Carl means is that the roller on the lifter has worn into the face of the follower, what has happened here is that the set up was incorrectly carried out , such that the roller was in permanent contact with the face or the follower. This is deduced by Carls statement that it wore in a few miles. The roller should never be in contact with the follower with the engine running !!
It is preferable to replace the roller with a hard face , e.g. Stellite  it. nothing to drop off then. When setting up the lifters use a bush on the camshaft the same diameter as the base circle of the cam, so that you have an uninterrupted view of what
you are doing. Take the pushrods out , and make sure the follower is sitting on the bush. Then sit and adjust. When you think you have it right , put the pushrods in place adjust the tappets and try again.
Trevor  7/18/00

Engine Balance Factor:I was talking to a rider recently who had discovered during a rebuild that his Shadow is balanced to a factor of 35%.  My understanding is that during production the line was generally balanced at a considerably higher factor, about 46%.  I must say that riding his Shadow proved the lower number to be quite smooth.  I investigated by doing some homework with "Motorcycle Engineering" by the late, great Phil Irving.  In it, discussing balance and torque reactions, he states that 35% is a very good factor for "medium" V twins, those falling between 45 and 90 degrees.  By the way, this 35% is based on TOTAL reciprocating weight, i.e. (as I interpret it, please correct me if I'm wrong), both piston assemblies and the weight of both small ends.   My question is what the general consensus has been amongst those of you who have investigated your machine's balance.  What numbers have you found as "stock" and what numbers have you run with what results.
Glenn Bewley  6/29/00

Glenn, I asked PEI about the 35% balance factor and HE said it may have a typo. Marty Dickerson built numerous Vinnys @ 35% and, like you said, they were smooth. Another one of those things that makes you say: Hmmm.   Cheers, John Ulver

Cylinder Liners: .L.A. Sleeves offer well proven and well made liners in oversize dimensions we have used with full success for many years .  Coventry Spares generally carry fine quality liners in + .040"  and  +.060"  at reasonable prices.

After removal and deep cleaning, the pair of  finned cylinders are closely examined and measured / compared.  The  purpose
being to Blue-print them to identical thickness top to bottom as well as being bored perfectly central and perpendicular to parallel top and bottom surfaces.  Their  inner bores are taken out enough to fully clean-up and provide a  smooth dead straight and round surface. Unwise to bore any larger than necessary as it loses cylinder strength / rigidty .

The new liner is mounted on expanding mandrels and its outside diameter is reduced dead true to its center and fully larger by  .004"  than the i.d. of that muff selected to mate with it .   At  the exact distance from its top where this liner shall emerge from the bottom of that muff, this sleeve is taken down  to suit one or the other main case register mouth bores - to a fine finish and  a snug slide-in fit into the bolted together cases and marked to identify this mating  for correct assembly .  The remaining  liner and muff are likewise prepared and mated .

The cool liners are fully entered into the heated alloy muffs and held hard-in until cooled off .  The top recess and head spigot
already having been reformed to original dimensions . Later, after final double grit lapping, we like to see an air gap of .003" between the two broad faces, this representing the differance in grain size .  This will close up and come solid upon application of the correct torque loading figure, ie. 30  to 32  ft.lbs. maximum .   No more is needed and actually harmful .

Before final bore and hone procedure, the thrust face oil delivery holes are sited carefully.  These break through below the  oil-ring grooves - at BDC - not into them.   Finally, we prefer to fit a lower liner mouth girdle clamp to prevent  any bell -mouthing while boring and honing .    Good luck .    Sid  Biberman    5/22/00

Camshafts: When Bob Guptil was playing go fast I bought Him a set of Emmericks' cams as He was tight for $.  So in 1977 the two of us head to Bonneville. Now, Ron Kemp had built this VERY sweet engine for Bob, but neither Parti or the rest
of us couldn't make Bob stay out of it, and little by little it would go slower and slower. Anyhow, in '77 it ran 137mph with Mk.2's and on the next run with the Emmerick/Andrews' cams it ran 136mph. Virtually the same, Bob pulls the cams out, hands them to me and says something like "You paid for them, they're no better than stock, they're Yours"! No, I didn't hurt him. I needed the ride back home.

I took the cams and tried them out, took them out ploted them on a spare engine wrote it down somewhere, and they are still on the shelf. They ran OK, but the bike sounded like a Maytag washing machine to me. A couple of years later Harvey Crane invited me into his Motor home at the SaltFlats to sell me some of his cams. "These got dips in them" says I. "Yeah, 'that's  so the valve will slam shut" says H.C.. I walked over to Dave Matson retold him the story and it turns out Dave had given Crane some cams to regrind correctly because they had dips in them and Dave wanted to Get them fixed!

A few years later in Wendover one night, we're sitting around telling each other how smart we are when on of us who owned a well known cam shop let it out that he and the guy he'd bought the business from had ground cams for years with the Masters set up backwards!  Moral, stick with Gary Robinson, or Phil Irving.                                  Cheers, John

Vincent Rods in order of Total weight----Big end weight-----small
end weight.

Vincent 1  607 grams-- 314---160

Vincent 2  594-------------333----208

Vincent 3  617--------------316----196

Early Carrillo    (A)    462-----240-----146

Late  Carrillo  (B)    569-----314----182.

Weight of big end bush    93 gram       small end bush   30 gram.

The Vincent rods were weighed complete with both bushes.
The Carrillo  without big end bush and small end bush  (A)
The Carrillo  without big end bush but with bronzed in small end (B)

So you can see that the Carrillo`s are not heavier than a standard Vincent, in either variety...and that Vincent rods have nothing in common.  Another little thing in my book suggesting that there is no such thing as a standard Vincent.....

Trevor Southwell  4/04/00

Regarding the extra oil pump for the timing case , I use a similar Honda 50ss pump but which is not driven by an added gear and the intallation is more compact than the Herve Hamon system as described in Forty years on.
I fit the pump centralised on the large idler (for twin engine)---on the little idler rear for Comet. In place of the std idler shaft holder I made a ??special ET66  with two ball bearings side to side.  A slotted spindle is tight fitted into the timing large gear which can drive the little oil pump placed on an enlarged steady  plate. Of course another ball bearing is needed
at the other end of the'drive shaft' at the back of the steady plate to have a correct alignment of this idler gear+shaft assembly.
The oil is pumped at the bottom of the crankase into the recess with a copper tube and an anti return ball valve at the bottom end. The pump push the oil under pressure into the timing cover through a n added rubber seal inserted in front of the higher steady plate stud after machined (an sometimes add some material)a slot and a three mm hole in the timing cover...+special
drilled stud ,banjos,etc...

WHY THAT???Who has never heard of worn out cams+followers+bushes+spindles after too short mileage?? Cams+folls are lubricated by the return oil from the heads.....OK Cam spindle+bush via the 170 jet to convert the large oil flow from the
original pump to ......Pressure able? to lubricate the camshaft plain bearings. This converted pressure is:00004 bar!..something like that! With this added pump the cam bushes and shaft+cam followers and cam friction are lubricated as they should be..under pressure. Several Twins and Comet  in France are such assembled and all is all right on this side now. After some checks at differents mileages no signs of wear compared with the std  at the same mileage.......Another report in 50 000more

 Francois Grosset

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