Generation IV Internal Engine - compression Ratios

Im looking to find out what the difference between a 10.5:1 CR compared to an 11:1 would be... Im gonna be running L92 heads and want the most out of my 402 on 93 octane ... someone help a dude out lol

Anyone??

The more compression the better if your gonna be running N/A. And at 11:1 you'll still be safe on 91 pump gas. As far as how much power your gonna pick up, that's debatable but I would guess a good 10 rwhp. Worth it IMO...

Just go with 11:1 you will be fine.

The real question is that i've read that l92 heads have come anywhere from 68-70cc chambers, if this is correct it would make this my situation. if my heads r 68cc and i run 11.41:1 compression can i run 93 from ANY GAS STATION?? the car is a daily driver, if the .5 CR isent going to make a big hp difference i wouldnt want to second guess myself everytime i fill up

68cc
-3 cc piston 11.41:1
-8 cc piston 10.79:1

70cc

-3 cc piston 11.15:1
-8 cc piston 10.57:1

How big a cam are you planning on running?

Its going to be a cutom grind from eps and the max lift is 660 so pretty big but still streetible

Its going to be a cutom grind from eps and the max lift is 660 so pretty big but still streetible

static compression ratio has little to do with what gas you can run. That being said, after speaking with Geoff at EPS, he advised me that his cams for the LS3/L92 heads do not have a lot of overlap to fight reverberation in the intake port. He advised me to stay at, or below 11:1 to run pump gas.

stock l92/ls3 heads are a 70cc chamber. 69.x if you wanna get really tight