hawks70

I'm rebuilding a Olds 350. There seems to be a difference in the thickness on the center bearing. The part of it where the sides wrap around the main web on the block? Those flanges seem thicker than they were on the originals and I think its causing some binding of the crank. Anyone else ever have similar issue? Any thoughts?

J-(Chicago)

Yes. You need to get a dial indicator and check the front to back thrust. (Crank shaft end play)

I have had issues with the chamfer on the crank journal riding up onto the thrust bearing. The bearings of course will have to be clearanced to make room for the crank if this happens to you. I have also run into thrust bearings where the overhanging lips are too thick. That would also result in no end play.
I stuck wet sandpaper onto a mirror for a flat surface, oiled it up, and clearanced it by hand to where I needed it to be.

.004"-007" is what you are shooting for. If it's within spec, BUT goes back to zero or 1 when you let go.....I'd guess chamfer issue. It should stay put and not spring back.

If you have not spec'd out all of your main bore diameters and crankshaft journal diameters with a dial bore gauge, you need to start there first.

ALSO...... you need to spec the inside of the thrust bearing lips, and mic the block flange, before you go mashing things together and distorting them.

hawks70

Ok. Thanks for your help.