Velocette Crankshaft endplay testing, maybe?

After a few months of procrastinating on the old MSS engine, it was time to get the next step going on it.As simple as this job seems to be, it has taken me months to figure out the approach.  This is even after watching the Velocette Owners Club engine overhaul video by Dave Allcock.  Even then I could be doing this all wrong but here it goes.

The simple process; place the crankshaft back into the case halves.  Space the two case halves apart with 0.004 shim stock and measure out the end play. Any end play found is the needed shim at the main bearing race.  The crankshaft should have 0.004 nip up or preload.  Sounded simple enough... But what if there is no end play when you measure it?

So the hold up have been the jigging up for measuring end play.  All the while, something in the video didn't quite make sense. The concept was right but the measuring seemed strange.  If you use the 0.004" shims and your looking to make 0.004" nip up wouldn't that measure out to 0.0?  Now, obviously if you are starting without any shims under the main bearings all is fine. But what if your testing an engine that has already been shimmed?

Well, I don't have any convenient 0.004" shim stock. I do however have 0.006". And maybe this is where things could be going wrong. The thought was that 0.006" shim stock would mean that if the cases are nipped up and your looking for 0.004" , with a 0.006" you'd have 0.002" play as you lifted the cases while the drive side of the crankshaft was locked into a vise.  The dial gauge would be affixed to the case in some fashion.

This was the mucking about that has taken months to get down to. Gathering bolts, cutting and filing the shims. Then making a simple bracket to allow the magnetic base of the dial attach to. In the club video it looks at if Dave attaches the dial indicator to the vise then takes the measurement from the case. The current vise in my workshop doesn't seem to be long enough to do as such. So will attaching the dial indicator to the case and measure the crank work? Dave also uses 0.004" shim stock to take the place of the nip up.

Set at rest

heavy lifting on case

 So where are we? Dunno, but this all makes me think that the shimming is too tight. On to removing the shim and try again. While were at it, the reason for this journey is due to the fact that when I got this engine it had been sitting for many years in a basement. When it was pulled apart, the cylinder was all worn  out and there was no piston. In between the cases was a cork gasket and from what the books show is that there is no cork gasket sealing the two case halves. Which begs the question, was it shimmed properly or was it shimmed for cork gaskets...  nothings ever easy.

The last step was to heat up the case half, remove the bearing race, check the shim. Then reinstall the race sans shim and do it all over again. If we get 0.002" play at the dial indicator ~ happy day, if not, back to the drawing board.

After about an hour a thought occurred to me, that if .006" shim stock gives no to little play why not try thicker shim stock as re-check for play? ok, back at it