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E: Engine Comet Timing Side Alignment


New Website User
VOC Member
I'm currently rebuilding my Dad's Comet. Plenty of experience building road and race engines but not Vin engines. Crankcases have new rollers and ball bearings fitted and flywheels are shimmed to be central pulling up against the ball bearing etc. Putting case halves together with the flywheels there is space between the shoulder that the oil pump worm (OP31) butts up to and the large bearing when sitting against the flywheel about .045" (timing side) . Also the half time pinion hits the outer race (outer ET94) before butting up to the outer bearing.
The obvious solution is to shim the inner bearing out from the flywheel to take up the space and push the oil worm and half time pinion out - This will be in the region of .050" . This will also mean that the pinion, worm, bearing inner are butted up to each other and the timing side flywheel when the outer bolt is done up (I realise this has nothing to do with the position of the flywheel in the case and that is taken care of by the drive side). There is nothing about this in KTB or Paul Richardsons book, am I going about this the right way?

I will be fitting a primary side seal. The gap between the oil scroll and the main bearing spacer (ET19) is very small and I doubt that much oil will get past it and the scroll (ET77) if working will extract oil. Seeing as in std form the bearing was open to the primary side and probably had some positive air pressure pushing some oil through this will now not be the case especially as I will be running a PCV valve. Ball bearing is now in so there is not the option of getting one with shields running in its own oil.Is there a way to push some oil in this direction? - Perhaps turn the scroll ET77 and put some holes in the spacer ET19? Or even mill away the inner portion of the spacer ET19 (I can cover the bearing from swarf).
There are several posts about this but nothing definitive.


Well Known and Active Website User
VOC Member
If I am following you correctly, I would shim between the scroll and the bearing inner to center the inner in the outer race. I assume this will position the inner to prevent the half-time pinion from encroaching on the outer race. That roller bearing can be shimmed further out as long as the rollers stay within the race.

The original design of the Vincent drive side did not contemplate using a sealed bearing. There was sufficient oil movement to lubricate an unsealed bearing. I would put it together and install the primary seal carrier. I believe that the one from Maughan allows you to install it with the circlip in place, so I would use their seal carrier.

Best of luck,



New Website User
VOC Member
Thanks David, you've confirmed what I was thinking. Its difficult to measure the position of the rollers, I'll try marking up the out race and revolving the flywheel a number of times. Should show a witness to where the bearing is running.
I have the Maughan's seal carrier, just concerned about the ball not getting any lubrication.

Thanks, Mark.

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