GatorFan08

iTrader: (1)

Im buying a 454 with 13:1 compression, and was wondering If could drive it on 93?? Its going in my weekend warrior, anyways the only reason I asked is because my buddy's 383 has 12:1 and runs 93 with NO PROBLEMS.

ZONES89RS

iTrader: (25)

Wel, if it has aluminum heads and you run the timing WAY back, yep.

mrdragster1970

..

I wouldn't say no problems, but as mentioned.
If you choke it way down and don't hammer it, who knows??

..

cambirdracing

iTrader: (4)

I had a Pontiac that I tried to do that with. it got to where I could change the head gaskets in any parking lot in less than a hour.

pancherj

There is a good real lead fuel additive out there called Kemco. I plan on using it in my 489 with 12:1 compression and iron heads. The guys over on Chevelles.net rave about the stuff. I haven't checked into the price yet...

mrdragster1970

.

If you have a real fuel system on there, it might be cheaper to just use E-85 if available.

.

1 FMF

iTrader: (1)

it would depend on cylinder pressures, but those are variable and dependent on other variables.
you can use the dynamic compression ratio, which depends on camshaft profile, to get a better feel but it won't guarantee that a certain octane fuel would not detonate under various conditions.

http://www.kennedysdynotune.com/Dyna...ion%20Tech.htm
http://www.empirenet.com/pkelley2/DynamicCR.html
http://www.hotrod.com/pitstop/hrdp_0...ion/index.html

RedGut86

iTrader: (1)

Ouch.

Definitely check out what the dynamic CR is as linked above. Pat Kelley is a great resource with some good free tools. I have run slightly higher DCRs than his recommended numbers with a aluminum heads without problems, but YMMV.

tom falco

Its all in the DCR. If the valves stay open longer the mechanical compression ratio means nothing. Check the DCR and that will tell the story. I run 12.5 -1 with no problem in my Chivelle. Big block