im in the process of researching building a new engine...i am familiar with compression ratios somewhat and what affects them but there is a lack of specific information...i just want to see if i can clear this up...
what is the minimum campression for a performance engine (in your opinion)
what is the maximum compression a car can run on pump gas and without having any problems?
what are the benefits of higher compression?
what range of compression is optimal for a street performance engine (in your opinion)?
thanks guys

 

with everything perfect, cam, extra, a aluminum head motor can go up to around 11:1 CR on pump gas, but that takes tuning, the right cam, and 94 octane gas(quality) all the time, I would say to stay under 10.5:1 and above approx 9:1, I would go (and planing to) about 10:1 CR, that way, any premium gas will be ok, also, the higher the compression, the morepower you make, due to more fuel/air in the chamber(per volumn)

 

what kinda of things can u do to drop compression? besides changing the pistons and heads...porting the combustion chambers? or thicker head gaskets? how much could gaskets drop it? thanks

 

Here is a pretty good tool to calculate your compression ratio.
http://www.sdperformance.com/cr.php. You will be able to change various parmeters and you can see the differences in the compression ratio.