Bearing Questions

[SUFFRN6]

I picked up a noise in my engine in the fall and just get my engine torn down tonite and my main bearings are a mess. The bottom end was last done 7-8 years ago. The upper bearings are 10 over and the bottom bearings are 20 over. I was wondering how much farther my crank can be turned, and if I can get larger bearings then 20 over. My crank is still shiny and smooth so I'm not sure if it will need to be turned, but if it does do I have anything to be worried about? I know that the cranks for these cars are pretty scarce so I have been worried about it all winter. Any help that you guys give me will be greatly appreciated. Thanks in advance.
Chris

 

[Intercooler]

How can you have one half of the bearing set .020" and the other .030"? It isn't possible! You can go .030" because my old motor was .030" but if the crank can just be polished do that!

 

[SUFFRN6]

Thats what I thought when I first looked. The top bearing has Clevite 777 010, and the bottom has Clevite 777 020 on it. Kinda of confusing.

 

[6PacktoGo]

Originally posted by SUFFRN6
Thats what I thought when I first looked. The top bearing has Clevite 777 010, and the bottom has Clevite 777 020 on it. Kinda of confusing.

Are you sure you read that right? With an 0.010 on top and a 0.020 on the bottom, you'd have to have a crank that was gound 0.015. First, no one in their right mind would grind a crank that way, and second, even if they did, that mix of bearings would never work right. Are you SURE don't have 0.001 on the top and 0.002 on the bottom? That would be done in order to get proper clearance for a crank that was 0.0015 under size.

In any case, have the crank measured by a skilled and competent machinist, and see what you get.