What type of fuel should I use with a 13:1 piston, stage 2 cam, port/polish, K&N filter...? I've been told diffferent things so I thought I would ask here. Right now I am using c12 and 92 octane half and half. Seems to run real good but haven't tried anything else.
Thanks

 

I wouldn't run any less than 100+ octane in that motor. 76 Unocal 100 unleaded is what I run 12:1 on.[img]i/expressions/face-icon-small-smile.gif[/img]

 

I think my mix is about 100. would higher be a waste or better

 

For a few extra bucks, why risk damage to your engine by mixing? Detonation can destroy a piston and rod without you ever hearing a single ping. I ran straight C12 in my 13:1 and will probably do the same for the new 12.5:1. You could try VP Red instead of C12 if you want to save a few bucks.

 

I was told that straight C12 was overkill. Is the mix I'm using no good? Anyone else have commentson the fuel for a 13:1? I want things as perfect as possible.
Thanks

 

do I risk detonation with the mix I'm using? Really would like some more input

 

Where did you guys get a 13:1 raptor piston from? Who makes them?

If you are at or close to sea level I would use higher than 100 octane. I would at least go with 104 or better. Also check your compression then ask the place you buy the race fuel from what octane you should run with their fuel with the amount of compression you have.

 

Alba advertises a 13/1, but only in a 101 and 100mm bore size, weather it is really a 13/1 who knows.
JEs 12/1 piston has a higher static com ratio than an actual 12/1, from what I have been told.

IMO 100 is too low, but maybe not. I guess it depends on where you ride. If it was LONG drags up BIG hills........I think 100 would scare the piston out of me.[img]i/expressions/face-icon-small-wink.gif[/img]


SandRappy, I hope you got my e-mail.

 

The JE 11:1 and 12:1 Raptor pistons were designed by a big-name builder to provide those compression ratios with a certain amount of material removed from the combustion chamber. If your builder (or you) don't remove as much material from the combustion chamber, the actual compression ratio is higher.

 

I under stand how the pistons domes are a standard size such as all 12:1 pistons have the same sized domes on the piston. And I know that because they say it is a 12:1 piston doesn't make that true. For example with a 105mm 12:1 piston you would think they correct the dome size so the compression ratio is still 12:1, but they don't. The actuall compression (static) ratio ends up being about 13.5:1.

I was just wondering what company actually advertises a 13:1 compressoin ratio piston, and I wonder if it is any different than the 12:1 or do they just call it 13:1 because that is what the static ratio is?