Cracked blocks
 

Getting desperate, have taken 4 8BA blocks to machine shop, all four had cracks too deep to fix. There is a block with .080 bore on ebay within reasonable driving distance. My question is .080 too much? https://www.ebay.com/itm/Ford-Flat-H...Faa3~B&vxp=mtr

Thank you all for your responses.

Re: Cracked blocks
 

The 8BA blocks can have core shifts like any of the other flatheads but any block with minimal corrosion and core shift can go out to 3 5/16" without any problems. I certainly wouldn't bore one that far until checking it with ultra-sonic testing for thickness just to be safe. That's 0.125" oversize. I personally would only bore it as far as it needed to go to clean it up but the possibility in there.

They may be able to even go farther than that but there is always more risk the farther they are bored. 3 3/8" is pushing them about as far as they can go.

Re: Cracked blocks
 

There are piston sets available with .083 oversize design so it might be that you can simply hone and use that block if all else is good.

Re: Cracked blocks
 

Based on the receipt, the block has a fresh bore that should finish at .080 over, with a bit of honing, right? If so, the block is almost ready for rebuild at that oversize. Since there is an option to make an offer, I wouldn’t hesitate to start at $1000 if ALL ELSE checks out.

Re: Cracked blocks
 

I noticed it did not say they pressure tested it. I would want that done. imho

John

Re: Cracked blocks
 

I would want a money back guarantee that it is usable on return of the undamaged block. If the seller hasn't been satisfied that it is usable then why should you be.

Re: Cracked blocks
 

Thank you one and all, definitely taking your advise into consideration.

Re: Cracked blocks
 

It appears to be a good block - as long as the seller will guarantee that it passes another mag and pressure test, then I'd go for it. It has about $500 of work into it - so it really isn't an unfair price in the end.