I just picked up a 28 Ford with a 56 331 Hemi which originally was in a grain truck. It's running ball&ball carbs and the truck intake.
Just curious what octane fuel is required for this motor?
56' 331 Hemi - octane gas?
Moderators: scottm, TrWaters, 392heminut
Re: 56' 331 Hemi - octane gas?
According to this site it is officially 7.5 C/R, and some hemis, when measured, have measured up to close to a full point lower than posted C/R, so it could be anywhere from 6.6 to 7.5. Should run on 87 w/o any problems. If you're where Sunoco sells 85 it would probably be good on that.
Re: 56' 331 Hemi - octane gas?
It would run on 79 I bet. lol
Re: 56' 331 Hemi - octane gas?
Probably. hemis can run a point higher C/R on the same octane as a wedge, so what octane would be needed on a 5.6-6.5 wedge engine?Rob wrote:It would run on 79 I bet. lol