Re the thread by Mr. Quinn
What is the max overbore for a 312 block? And also a 292?
If one has a good 312 block, what is the max cubic inch possible?
Thanks
Jim

Maximum overbore will vary from one block to another.  If you're going to extremes, have the cylinder walls sonic checked so you know.

There have been a couple Y's in the area of 400ci but they require custom parts and expertise, so maximum displacement has maximum cost, too.


Lawrenceville, GA

Good question. I’ve always sonic checked the block, and I’ve done 2 blower motors where I didn’t use the “maximum standard overbore” due to wal thickness. In one case we shifted the bore centerline slightly to move away from the thin spot. Better smaller than wetter.

. Edit: Beat me Charlie. On my 340cid stoker 312, we had to clearance the rods from the cam.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

.A note from Ford, they only made pistons for  312 s up to 40 thou over. (aprox. 319") However, many have bored them 60 over & usually it's o.k., but a sonic check is a good idea. That results in 322 cu. in. Beyond that is sketchy & if you have a problem with say a broken ring, then what?. And as Charley points out, with a custom order crank & much smaller rod journals & so on, it's possible to go quite big, but it requires special expertice & big $$$$ !!  

P.S.- Jim; If you want to get info on a stroker kit, John Mummert Machine has kits that will get you into the 330+" areas. Link from this site to his site, it's very informative..


Paul

Thanks so much
Jim

I'm .80 over with Egge cast pistons and trouble free. MIKE

Mike, still lovin his 57 t'bird after 53 years!

As mentioned from a bunch of guys: sonic check the block. That’s about $90. Probably money well spent. Then go from there. I just picked up another 292 block with stock bore for $100. So, determine what is logical/feasible. Unless boring to the max and stoking the motor out is your thing. Of course, that gets expensive.
Good luck
Kev

Mike: Was your block sonic checked before the 80 thou overbore?  And were you starting with a 292 or 312? 


Paul