Compression ratios

[Honda Jay]

I wanted to build a Sparks National Kit, and i was wondering what is the highest compression piston i can run with pump gas?

Than if i wanted to get a high compression piston and have to run race gas how much more power will it give me and how will the reliability hold up?

How much does race gas and at what octane is gas considered race gas?

[Honda Jay]

Sorry guys, i wanted a Sparks 416 National

[Chanman420q]

i think the highest you can go without using race is 11:1 and race gas on average is about 5 bucks a gallon. Usually 110 octane. If you get something like a 11.5:1 or 12:1, most people mix 50/50 to get a octane around 98-100.

[crashinmatt]

the highest compreesion ratio u want to go is around 11:1 for pump gas, of course, it all depends on other factors as well. but as for relaiblitiy of higher compression ratios, the higher u go the more stress on the crank and rod. if u went crzy high compression, anything over 12:1, u may want to get an aftermarket rod installed, that will increase rod reliability.as for price of race gas, it varies to location. around here at some stations, its around 3.50 a gallon. but gases like VP and such, ur lookin at around 5.00 a gallon on up.

Than if i wanted to get a high compression piston and have to run race gas how much more power will it give me and how will the reliability hold up?

Higher comp will make you look like this :D

Reliability depends on many things including how many hours on the engine and what comp and mods etc.

[YZROOSTINYA]

i run 11:1 on pump

get some air scoops and you will be ok