Main bearing shims

[JM 35 Sedan]

I agree with GM. The numbers you gave are too large to be actual bearing clearances. If .038" was .0038" and .058" was actually .0058", those numbers would be more realistic.

Note: this post was made before I read post #20 which explained why the earlier numbers given did not seem realistic.

[Tinker]

Sorry about that jm.

[JM 35 Sedan]

Just wondering if putting that cap on correctly and torquing to 20 '#'s allows the crank to turn freely? If not, I would wonder if that crank is bent from mishandling by previous owner? He may have also realized that crank locked up when mains were fully torqued. Just a delayed thought.

[Tinker]

I turns well, not smooth. Then again it is a used engine. The guy I got it from has FH for sale every so often. I was able to pick this one up fairly cheap. Just an engine to mess with, learn about FHs, and maybe be a static runner. It came with the heads and an aluminum intake. I have a fresh rebuilt in my truck, so this isn't an engine that I have to have running now.

Could have been a lot of things that has happened to this motor. No real history on it. Everything is fixable with a bucket of money, but purpose was to not do that.

[Ed Pitts]

You can check for high spots by using prussian blue on the bearings and then torque the caps and rotate the crankshaft twice. Remove and check the transfer. I have used lipstick as a sub for prussian blue. This will give you a better feel for the bearings.

[Tinker]

Thanks Ed that is a good tip.

I feel the center main is too far gone to make this a cheap and reliable runner. To bad as the front and rear look good. (I'll try and get some pictures of the caps for the heck of it). It will need a babbitt job or have inserts installed. Plan to shelf it for now. Learned a lot with this one and thanks everyone for their input.