Compression vs Octane
 

I'm currently running flatop pistons in my 350 chevy with a compression ratio of about 10.3:1. If I change to a .100 dome piston and bump the compression up to 11.3:1 can I get away with 93 octane gasoline?
Thanx

Re: Compression vs Octane
 

I think so. It is important to run some lead for cooling and lubricating purposes. I use Jack Podell's REAL lead octane booster that gives me around 100 good octane. I mix like 12 ounces to around 12 gallons of 93 octane. I am running 10.5 to one in my 1969 Z/28. NO problems with that stuff and I have my timing around 40 total degrees. Sam

Re: Compression vs Octane
 

i've talked with engine builders about the same thing before and some say its alright and some say you better run 100 octane or better. if i had a substancial amount of money in a motor i would run a higher octane than 93.

Re: Compression vs Octane
 

Your camshaft selection is critical. Your mechanical compression may be high, but depending on the cam, the actual squeeze may be more or less. What cam are you running?

Re: Compression vs Octane
 

I'm running a Comp Cams XE 274. I believe it's about 480 lift with 230 duration? By the way I can't endorse these cams enough

Re: Compression vs Octane
 

I agree totally that your cam selection is critical to how much static compression you can run. The larger the cam ( ie duration ) the more low rpm cylinder pressure will be bled off which will allow you to run higher static compression with lower octane gasoline.