9.5:1 comp with swirl ports

[punched355]

Hi just wondering if anyone has built a 5.7l TBI with 9.5:1 compression and swirl port heads, curious whether or not im going to have detonation problems. Im building a torque monster that will never see over 4000RPM's and due to the fact the only fuel i can get here without ethanol is supreme figure i might as well use the octane.

 

[76zimmer]

I think static compression is ok, but try to figure your dynamic compression, which takes into account your cam timing. Are the heads Aluminum?

 

[punched355]

I used a dynamic compression calculator and figured 9:1 so i should be fine, and no im using cast heads

 

[63chevyll]

I have 10.3:1 with stock tbi heads on my wifes car.

I'm conservative with total timing and only run premium. I geared it to stay in low RPMs while cruising. About 4500 is all its worth, which is fine with me.