What is the highest compression I can go on regular pump gas?

Thanks!

 

13:1 with good tuning. 12.5:1 if you want to be a little safer

 

I thought 12:1 with Hondata tuning. And 93 octane

 

All depends on the piston design, but off the shelf components I' say 12.5:1 with good tuning.

 

i'm running 13:1 on Arias dome top pistons. no problems so far. u just need a good tune.

 

Your static compression ratio had nothing to do with what octane fuel you need to use. With a properly cammed engine you could run 18:1 if you wanted. Formula 1 engines make 850 HP out of a 2.4 liter engine and run 85 octane fuel.

 

Proper cams alone won't allow a honda motor to run 18.1 compression- don't try it. Professional racing engines are rebuilt often and aren't designed for idling. Even if you had a formula 1 motor in your car, you wouldn't want to run 18.1 comp unless you planned on rebuilding it fairly regularly. Higher compression adds more stress to the motor than any other method of power addition. The more compression, the shorter the life span of your motor. Sealing in the increased pressure and managing the extra heat are the two biggest concerns when calculating maximum possible compression.

 

I wasn't insinuating that he should run 18:1, I was just saying it was possible with the proper cam. I disagree that increasing your compression ratio adds more stress than any other power adder. A properly built engine with 9:1 compression isn't going to last longer that a properly built engine with 13:1. They would be 2 different engines. The 9:1 would be a low rpm engine and the 13:1 would be a higher rpm engine. The effective compression ratio, which is the compression ratio measured fromt he point the intake valve closes, should be about 8 - 8.5:1 on most aluminum head 4 valve engines running pump gas. Note: The effective compression ratio is not the same thing as the static compression ratio.