whats up guys, i tore into my 355 i just picked up to do a re-gasket and new cam+lifters. i decided to drop the oil pan to check everything out before it goes in my car and i found that the crank has wayyy to much play, so bad the the crank has deep scratches, looks like a snails shell. i think the max play is like .007 but im not sure, my play is .072. is there anyway to find out which thrust bearings i need? '

thanks, justin

 

There are no discrete "thrust bearings" in this type of engine. It's part of the rear main bearing.

The "scratches" are what's causing the "play", not the other way around. Basically the crank is ruined. Might be repairable, I couldn't comment on that without measuring it, your machinist will be able to tell you.

You need another crank and a set of bearings; and of course to tear the motor down and remove the cam bearings and all the plugs at the ends of all the oil passages, and take it to the quarter car wash and run rifle brushes through them to get rid of all the metal chips in there, so the first thing that happens when you fire up your new build, isn't a bunch of debris getting flushed into your new bearings and ruining your new build the same way.

 

so once you get crank walk you need a new crank? I cant upload a picture but the grooves are in the counterweight

 

Once you have a damaged crank, you need a new crank.

 

You also might want to check your rear main bearing cap and make sure all the crank walking hasn't done significant wear or damage to the thrust surface on the cap.

 

Don't bother with a pic, we've all seen destroyed cranks before, there's nothing new in what you've got there.

Yup.

Or, have that part of the old crank welded up and turned down.

Which costs about as much to have done as buying a NEW crank these days.

No sense in spending NEW CRANK MONEY and still only having an old beat-up repaired stock one.

A classic example of how, just because a thing "can be" done, doesn't automatically make it "A Good Idea" to do it.

And as Pat mentioned, if the block is damaged, then it's trash too. Or, if the rear main cap is hurt.

 

alright, I appreciate all the help guys. luckily I have a spare crank, hopefully nothing else is damaged too