i am not sure if this is the correct section to place this question but i have recently upgraded my 440ex with a new 440 kit with a wisco piston and magnum stage 2 cam i am running 12.5:1 compression and i have been told a couple differnt types of fuel to run i was wondering what any of you guys thought to run in it. i was thinking pure cam 2 but i herd running it pure is not so good. if you can tell me anything id appreciate it alot, thanks, house

 

with everything I did to my motor and i'm running the same compression ratio, I have to run a 91oct or higher
I run a mix of 91 with 105 and it runs great. the higher the compression the higher the octane you need to keep the motor cool
and to keep it from detonation knock. (pinging)

 

it probably depends on what the true compression ratio is along with what the quench area is. i would run over 100 octane to be safe though