Rebore vs Sleeves
 

Have a block that had .070 oversize pistons. Should I rebore to the next suitable size or sleeve to standard? Suggestions?? Thanks

Re: Rebore vs Sleeves
 

go with rebore till you can't get pistons, then sleeve

Re: Rebore vs Sleeves
 

I agree bore over size as long as you can. I only use a sleeve when you have to.

Re: Rebore vs Sleeves
 

Your next oversized will be .080, measure carefully and see if it will clean up there.
You can have it honed being only .010 away.
Your next size is .125 it will have to be bored for that one.
I also agree sleeve only if you have to.

Re: Rebore vs Sleeves
 

Brattons lists .100 pistons.

Re: Rebore vs Sleeves
 

While the above comments are correct, the one comment that I will add is that sometimes the walls have been eroded away where it is not prudent to go 0.100" or 0.125" over because of wall thickness. I actually have a sonic tester that is much like an ultrasound for humans. Ask your engine rebuilder if he can check the wall thickness for you, and also get him to mic the bores to determine if it will indeed clean-up on 0.080.


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Re: Rebore vs Sleeves
 

Brent has a good point but I have never seen an A or B block that couldn't be bored to 4" (+.125") Racers used to bore them +.185".

Re: Rebore vs Sleeves
 

I'm not sure how sleeves seal in the Model A block which wasn't designed for sleeves. My experience (one engine) is that coolant leaked around the sleeves into the combustion area.

Re: Rebore vs Sleeves
 

In a nutshell, the cylinder is bored undersized (-typically .0025") of the cast iron sleeve that will be inserted into the bore. The sleeve is chilled with Nitrogen to shrink its diameter and the cylinder bore is heated to expand the diameter. The sleeve is inserted into the bore, and when the two metals equalize in temperatures, there is an interference fit. If there happens to be a pinhole into the cylinder wall, a correctly installed sleeve will dam the coolant. If incorrectly installed, it likely will wrap into the crankcase.