What’s the highest compression you can run on the raptor with 91 octane? I’m looking for a cam and piston kit

thanks

 

I wouldnt go any higher than 11.1 compression if I was not willing to run racing fuel. I ran pump gas when my Raptor was 11.1 without any problems; Now that it has a higher compresssion it doesnt like pump gas. Slim

 

I have run pump gas with my 12:1 686 but only for a short time. I didnt hear any pinging or anything like that but for safety sake I try to run at least 50/50 mix. My carbs seem to leak less when I mix 110 with 93 than running straight 110 octane stuff.

 

slim660, when you were running 11:1 what motor mods did you have?

thanks

 

I run 91 on my 11:1 craycraft 686.

 

It seems there used to be alot of 10.75 compression ratio in the past, what changed that most have 11.1 compression now. I'm not an expert in this feild and fairly new to quading.

 

I hear a lot of the Raptor pistons listed as 11-1 are actually 10.75-1.

 

aren't most lower than rated? i would stay in the 11-1 range.

 

12:1 and all I run is race fuel B-42!!! No problems

 

I have the 12:1 JE which, I've heard, is a little closer to 13:1 than it is 12:1. I run straight C12 and don't have any problems since I replaced the factory carbs.