I have seen several time that a 272 has been bored to a 292. Can a 292 be bored to a 312?

 

Yes walston a 292 can be bored to a 312 sized piston, although a 239 cannot, they are physically the same thing outside the engine from the 239 to 312, but 239 has different sized cylinders, if that makes any sense, but yes you can ........Janet

 

pre 1960 292's will easily go to 312 plus .060 size. With the 60-64 blocks Id sonic test first. With the cost of 312 pistons being much higher than 292 and even their standard oversizes there isnt any real benefit to go that big. Plus every pass with the boring bar costs more money.

Many 272's and truck 256's will also go 312 but again sonic to be sure.

If you have a 312 crank then have it cut to 292 journals to run in a 292 block.

 

Mummert's website says a .060 292 with stock 3.30 stroke crankshaft will yield 301 cubic inches.
If you used a 3.44 stroke 312 crankshaft in that same .060 292 you would get 314 cubic inches.
Can you bore it out past .060 is what I'd like to know!

 

I guess that is my real question also, if the engine has been bored to +.060 and is worn, do I need another block?

 

Not necesarily, you can always sleeve your block.
But depending on what that costs, you may as well look for another block.
Now here's the tricky part, trying to find a good block that's not worn out like yours!
They're out there, I found my standard bore 312 engine sitting in a wrecked 57 station wagon & only had to go .030 on it.

 

If your block is a 60's block, I would look for another block. If your block is a 50's block, yes, I would bore it to .080 and use 312 +.030 pistons.

 

Thanks Guys, I am not sure how accurate my mikes are, I'm taking it to the machine shop tomorrow for them to measure them.

 

292 bore is 3.75. 312 bore is 3.80. Everyone I have seen agrees a 1950s 292 can be bored to 3.84 (.090 over original 292 size). Some of us have blocks bored further than that. Sonic testing required.

 

Machine Shop called, the worst wear in my block is .0038 over original, so we can bore to .0060 and the block will have new life. Good News!

Walston

 

Make that .038 and .060 respectively.