Is there a octane compression chart?

[vara4]

I'm looking for a chart that tells differant compression ratios and what octane you should be using for that compression.

~ Vegas ~

[techinspector1]

I looked for this several times and although I found some info, it was not definitive. According to what I found, the upper limit on using pump gas is 165 to 175 psi cranking compression. You can't just say that a so-and-so octane will support a so-and-so compression ratio because you have the ringer of cam timing thrown into the mix.

[Mike P]

Just to add a little bit to Richards answer, besides cam timing other factors that have an impact on required octane in a real world engine are head design and material, altitude and ignition timing.

[vara4]

Well go figure guys, I once told a guy that I ran about 110 oct. to run 11 to 1 and he thought I was crazy. But I was running a stock type ignition system, with a wild cam in a Dodge 440.
Thanks for the replys anyway.


~ Vegas ~

[Pat Monaco]

Will this help you?

http://www.diabolicalperformance.com/hotrodoctane.html