91 octain fuel

[jaf]

Anyone know what compression or compresion ratio that premium or 91 octane fuel becomes benificial to a 2stroke sled engine,such as 130 lbs compression or 12to-one compresion ratio I have heard from some sledders that on stock engines 91 or higher is not necesary beyond 4500 feet altitude

 

[new24stroke]

My 03 800 HO has 14:1 comp head I can only run 91 about 4000.Any thing lower I run half avgas with premium

 

[Rucky]

My 03 800 HO has 14:1 comp head I can only run 91 about 4000.Any thing lower I run half avgas with premium

what octane is avgas?

 

[new24stroke]

100 LL which is 100 octane low lead.It's not much more than premium

 

[Summitric]

You Can Get Av Gas In 90 To 125+ Octane Ratings(MOST COMMON BEING THE 100 TO 105 OCTANE)..... Different Grades, Just Like Automotive Fuels.......

 

[.08rider]

I am just building a climber with rk tech big bore,should i run straight race gas or is a mix with premium enough?I can get vp 110 for a good buck,but it will go farther if I cut it.

 

[jaf]

I think it might be a good idea to speak with the engine builder as they will have a good idea of compressions and other things affecting detonation that will dictate what fuel you may use ,you can keep some cost down by using avgas,mix also racefuel mix