compression questions.

[flotek]

Originally Posted by drag shee

i was thinkin of about 110 race fuel and maybe a 17cc dome. what kind of compression is that

like everyone says, so many factors ,but id guess 170psi with a dune port and 17cc domes .110 should work great

[370banshee]

theres alot of factors there.... 170 with a drag port might be bit much for even 110.. thats gonna be a very long ex. duration and a hot hot cylinder temp...... don;t forget your gonna need advanced timing to work correctly together.

[fiveOnick]

Originally Posted by Flattrack

It Boils down to Several factors Is it ported ? What kind of Port timming dose it have? Stuff like that will Make the differance....

This is the only applicable answer.

How tall is the Exhaust port?
How far advanced is the timing?
How much compression?

[flotek]

elevation also applys .....people throw around the word"drag port" to often IMO . if yo uhad a true ballz to the wall dra gport youd have like no bottom end and it would fee l like a xr50 till 6,ooo+ rpm then BAMM hang on and try to keep it in the powerband ,really only good for srtaigtht line racing yard and trail putting will just make it hot and load up and unfun.most guys seem to have a mild dune port and call it stage 17 drag porting

[onefast90lt250r]

me and my brother always run kam 2 110 octane race gas in are big bore 250r's my brothers 310 needs it but mine runs fine on 94 i run it more for the smell and we get a pretty good deal on it because my buddy runs big block modifieds and gets a crap load of it so he gets it alot cheaper. as to harming your engine the only way you will damage it if your runing to low of an octane

[370banshee]

if you run to high octane fuel your wasting your money.. so by you using 110 in your engien that runs great on 94.. you are effectively making your engien make LESS power and wasting your money.....

[fiveOnick]

I dont agree with that but we dont need to get into that long ass discussion.

[Dier-Wolf]

The higher the octane just means cleaner burning, in other words has more detergents in it (partly oil) its been tested before on many occations that lower Octane fuel in 2 strokes with proper oil mixture runs much better and with more power than with higher octanes.

[flotek]

it depends on what race fuel brands too, higher octane race fuels will burn slower than pump gas and aid in detonation resistance . but if it has additives like lead or oxygen ...etc it will also add power even if that specific engine doesnt have high compression .,pump gas isnt requlated like the race fuels and often it is subpar fro m time to time
my 2 pennys

[370banshee]

Originally Posted by Dier-Wolf

The higher the octane just means cleaner burning, in other words has more detergents in it (partly oil) its been tested before on many occations that lower Octane fuel in 2 strokes with proper oil mixture runs much better and with more power than with higher octanes.

sorry dude but higher octane doesnt; mean cleaner burning....