16-03-2018, 08:22 AM
(15-03-2018, 11:47 PM)Bob Culver Wrote: I presume the timing gear is removed. Even if the front of crank had been bent, would likely cause flywheel runout but unlikely to affect the smooth turning of rear main. The droop of the unsupported crank depends a lot on the type, tolerance and wear of the front bearings. New or shimmed ac front races can allow almost no droop. Whether or not this is a desirable condition is questionable.
At this delicate stage the top priority is not to break the front lip!
Thanks for the comments.
Its a standard set up, roller rear/ac fronts, ten thou off the crank and plus 30 pistons, so hasn't done a lot of work.
The front bearing housing is the shorter version, and the assembled bearings projected a little from it.
I suppose I have never tried this particular action before, maybe they all do it.
Crank was just supported by the front ac bearings, which on removal appear to have little or no preload.
Camshaft removed.
How much pre-load should there be on the front angular contact bearings? In the green book, Jack French says "from .002" to .008", with the higher figure "beneficial".
What is the current thinking?
Jack thought that .0013 clearance in the rear main "is quite acceptable". This rear main is as good as, or better, than that.
Cannot find any cracks in the crank.
Front bearings are a push fit in the 'case, so it is going back together with Loctite and a bit of shim for pre-load and see how it goes.
Cheers
Simon