d_och23

whats thehighest compression you can go and still run pump gas?

Mustangkiler

Depending on timing 10.5 to 1, ive seen ittried with11 and upbut usually you have to retard so much timing it cancels out the extra compression power or even worse you blow a hole in the piston.

d_och23

ok thats what i wasthinking. and when i run nitrous i would haveto retard the timing as well, right?

Mustangkiler

yup

67mustang302

It's gonna depend on camshaft timing as well. A cam with an intake valve that closes later can run more compression than an engine with a cam that closes the intake valve sooner. But yeah, generally around 10.5:1 is a safe maximum in most cases if the tune is correct

Matt Paul

Ive ran 94 sunco with 11.5:1 and cast iron heads and timing at 12 degrees.

67mustang302

That's thebad thing about California, the best we have is 91, and with a crapload of additives no less [:'(]

WhiteWindsor

I have 11.1, 33* degree's total timing and run 93 octane. My cam is 625/661 lift, dur @ .050 is 246/259 with 112 ls., it is a nitrous grind.The cam and motor also loves race gas, but is steetable with detonation with the 93 and it is not a daily driver but i do cruise with it.