392 Hemi Old Style

392 Hemi Old Style - 09/15/11 12:43 AM

I am building a motor for a freind and am wondering if anyone knows how much these motors can be over bored. it is at .030 over now.

Posted By: quickd100

Re: 392 Hemi Old Style - 09/15/11 02:01 AM

I believe they were pretty stout cylinders but give 'Triwaters' on Moparts a shout, he's an expert on the whale motor. Dave

Posted By: Cab_Burge

Re: 392 Hemi Old Style - 09/15/11 03:20 AM

Quote:

I am building a motor for a freind and am wondering if anyone knows how much these motors can be over bored. it is at .030 over now.

I have seen 392 blocks crack cylinders when bored .090 over

Don't bore it any more than you absolutely have to, the orignal blocks where designed to be small bores(3.750 was stock on the 331 if I'm remembering correctly) once Mopar changed the bore size to 4.00 they had to make and design another motor( B&RB) for production use

I have ran a lot of the early Chrysler Hemi motors

I like them a lot but they do have thier limits

If your friend is looking to go all out on a early style 392 motor have him look at the Donovan blocks and Hot Heads aluminum cylinder heads

BTW, back in the day .060 was consider the max you wanted to bore a 392 block, regardless of which block, standard, RR or A-1 block

Posted By: 392charger

Re: 392 Hemi Old Style - 09/15/11 06:58 PM

My 1957 A-1 block is .080 over. Never been a problem but to be fair it a rather mild 13 second street motor with a cam/headers/intake. And I agree with Cab. I wouldn't want to lean on mine real hard at .080 over.

Posted By: RodStRace

Re: 392 Hemi Old Style - 09/15/11 08:19 PM

If it's going to have any cojones, have the thing sonic checked (the best answer) and check piston availability first!