Question on crank

Cheeze

Registered User
Hey guys I have a question for the powers that be. I am in the middle of rebuilding my motor in my 94SC. The motor in this car was previously a reman motor. I pulled a crank out and check the bearings and they are marked as being 30 thousandths of an inch turn already. I know that the crank is not supposed to be turned off more than 10. There is nothing wrong with my crank other than the aforementioned bearings. My question to you is can I just go ahead and buy new bearings for this crank and still use it?
 
Last edited:
As long as you can actually find the bearings you need, go ahead and re-use it. I'm not sure about actually locating .030" under bearings though.
 
Thank you Mr. Dalke!

That was not the answer I was expecting however, it was the answer I was hoping for! Now to find myself some bearings.
 
Well, I probably should qualify what I said. First of all I would not be turning an SC crank .030" under. I just meant that if you have a running combination that is .030" under then I wouldn't just throw it away. The .030" under, is that on the rods, mains, or both? The most important consideration on a crank that is turned under size by any amount, is how the radius has or has not been maintained on they rod journals. I've seen cranks that were cut .010" under that were seriously weakened by an improperly executed radius.

Most crankshaft failures are due to wheel hop or a failed harmonic balancer rather than an actual journal strength issue. If you want to add some insurance to it you can have it nitrided for surface hardness which is basically all that was removed by the grinding process.
 
I have a buddy who works at a machine shop and has the crank right now checking it over. When I pulled it out of the block the main bearings were stamped 0.75mm on the mains and 0.50mm on the rod journals. The crank doesn't look bad at all to me. I only pulled this apart due to me having the heads ported and found that my block was cracked at one of the head bolt holes.
 
Back
Top