Ok... i know lower compression is better for blown or turbo engine.. so... is higher better for non blown/turbo.. what about NOS... higher as well? i think so.. but please correct me if i'm wrong..


now.. here's the real thing... ok, looking at this site.. reading these specs..

HYPEREUTECTIC FLAT-TOP PISTONS: 58cc=12.6-1, 64cc= 11.7-1, 72cc= 10.8-1, 76cc= 10.3-1


ok.. now.. they ran the 72cc=10.8-1 compression. what's the CC part.. the size of the piston head? or.. how big/tall it is? or.. what..

Also.. does that cubic cenitimeters make much of a diff there? like.. which would you get more power from, on a non blown/turbo/nitrous car.. the 12.6-1 w/ the 58cc, or the 10.3-1, 76cc? what really is the difference in other words... do these #'s have to match up w/ the heads.. i was told they do... what about w/ the cam, no.. correct?

thanks. :-)

 

yes, basically higher is better for NA and lower for power adders. the cc is the volumn of the chamber in the head. as for what makes the most power you need to look at the entire combination and not just the compression ratio.

 

I'd get a book and start reading up on engines. The higher the compression the more power potential. But if you make too much compression on a N/A engine, you'll have to start running race fuel just to get combustion right. I am almost sure you can run more compression with aluminum heads over cast irons (help me out guys if I'm wrong) but that's just what I have read.

 

that's what i thought.

so.... about what compression would you have to start running race fuel? which... would suck, rofl. you can run 12-1 compression on top notch octane can't you?

 

your timing is also critical as well as the the material your heads are made of, an cooling system. Also higher compression is fine with nitrous, but not with forced induction. 12:1 CAN be run on the highest rating pump gas with base timing at 0 degrees and very little advance throughout the powerband and aluminum heads but you are playing with fire. everything has to be dead on otherwise you've just toasted your motor unless you know where you can get leaded gas lol. I'd say 11.5:1 with aluminum heads and 11:1 with iron heads is the most you'd want to run if you are going to rely on pump gas.

 

why higher compression with aluminum? aren't aluminum less durable?

 

heat disapation is better with alumnum than iron

 

The cam profile has alot more effect on what compression you can run than anything else.