If I can only get the too-tight endplay finally set...
Cast cranks are notorious for having such a large radius on the #1 main bearing journal that the thrust surface never reaches the bearing itself.
I have had to machine a larger chamfer on the inside on the # 1 bearing to get the proper endplay. Not to be ragging on your choice, but it was the one and only time I've used a cast crank.
Gary: I can picture exactly what you're describing. Shame, shame on me for waiting to set endplay until after I'd sealed up the shortblock... When I recently had the flywheel's snout machined .005" (0.13mm) to increase the space for the shims between the #1 bearing and the flywheel, my test-fit gave me a reading of 0.10mm, which was right in the middle of allowable tolerances. Test-fit was done with flywheel torqued to approx. 225 ft-lb. After installing the flywheel and tightening to same amount, the endplay went down to 0.04mm which is 0.03mm less than minimum.
An old-time VW mechanic friend of mine (trained at VW dealer; then worked at VW of America's HQ Service Shop for years) thought it was OK to leave out one of the three shims, as his reason was "Porsche 356 used only 1 shim for endplay". Sure enough, after reading the late Harry Pellow's "Secrets of the Inner Circle", 356's did indeed only use 1 shim! Wonder what they knew better than VW's engineers?
So either I can leave out 1 shim (and second-guess VW's engineers ) or take the flywheel again to have it machined some more and use one thicker shim...
The problem with doing that is if the radius is the problem, your bearing will edgeride the radius and be destroyed in short order.
Maybe you can see in a cylinder hole to tell if there is any clearance between the crank and thrust surface of the bearing with the flywheel on. Might be able to sneak a feeler gauge in there. If it isn't against the thrust surface, I'd tear it back down.
Don't ask me how I know.
I think what Turboblue means is, take off the #3 cylinder / Piston..... shove the thrust up tight towards the front of the car / front Thrust main brg.
Try to slip a feeler guage between the end of the crank / thrust brg.
If you can... it has to come apart...
You shouldn't have the Pistons / Cylinders installed anyway... Untiil the thrust is set.
Joe and Gary- again, I can picture what you describe. Well, I did install the P/C and heads after getting the 0.10mm endplay; then after the installation I double-checked the play again which is when I found the tightness. I'd like to get this engine "right" so I guess I'll tear off the left head and #3 to view that thrust surface as you described. If the crank radius is bad, I'll need to tear the engine down. Thanks for the tips.
BTW- the case, P/C and heads are from a left-over engine. I am clear that with the cam and "small" valve heads it'll be a torquer; which is what I want.
Early this morning before work I removed the left head and #3 cylinder. By cranking the engine a certain amount, I was able to view into the case hole past the piston and see the front cheek of the #3 crank throw and the back (thrust surface) of the #1 bearing. I removed the flywheel, which gave me about 1/32" end-play which I was able to view thru the case hole. Next I took out my thinnest feeler gauge (0.04mm = 1.6 thou inches), pulled the crank rearward to maximize endplay, carefully inserted the feeler gauge between the bearing edge and the crank cheek, then pushed the crank forwards to reduce the endplay. The feeler gauge had a drag to pull out, meaning that the crank was coming forwrd enough. What I'll do when I'm back is to rig up the dial indicator and see how much more I can push the crank forwards after I remove the feeler gauge; will be a value less than 0.04mm...
) or take the flywheel again to have it machined some more and use one thicker shim...