I know this gets brought up from time to time and I did a quick search but found nothing to directly answer my question. I picked up a 59A-B a few weeks ago. The motor is complete from carb to pan but has been in the weather. This weekend I pulled the heads to find #4 and #8 pretty badly pitted. The rest of the holes are OK. It was rebuilt some time ago by a commercial shop and has a rebuild tag in the bell housing. It has exhaust valves on the intakes and the exhaust side. The engine is already bored 60 over. I'm trying to make this thing live again. Is it generally considered safe to go up to .125 on most blocks or should these blocks be sonic tested after a certain point? I may look into sleaving just two holes and keeping the overbore to a minimum. Opinions?
on 59a blocks .125 is pretty safe. you can go 3 3/8 or even 3 7/16 if you sonic check the block. I know of a 3 7/16x 4 1/4 inch motor being put into a 30 roadster. 314 cubes!!!!!
Check the availability of pistons. If you can find them, .080 over slugs might be the answer, and you still have enough meat on the walls to rebuild again later. I don't think I would sleeve it, but that is just my opinion.
In the 50s the round d round boys would bore big then sleeve the block then bore the sleeve to what you want.
Not sure, I think 3 7/16 is the max off the shelf piston. Isnt 3 5/16 = 120 over? If your at 0 you got a long way to go.
Not sure, I think 3 7/16 is the max off the shelf piston. Isnt 3 5/16 = 120 over? If your at 60, you got a long ways to go.
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