Just wondering, can you run av gas in our quads. This is the 100 octane, low lead. I have heard some people say its just fine, others have said it isn't good on the motor and seals. Does anyone know?

 

Aviation gasoline or "av gas", is blended specifically for use in small aircraft. It's also commonly used by many high performance engine owners because of it's high stated octane rating (usually 100-110) and the relatively low price compared to racing fuel. Unfortunately this fuel is not all it appears to be. Avgas octane is rated on a different scale than gasoline's intended for ground level use. What is 100 octane "av", is not necessarily 100 octane "ground level". Besides this, there is also a big chemical difference. Normal ground level race fuels are made up of gas molecules that have a "light end" and a "heavy end". The light end of the molecule ignites easily and burns quickly with a low temperature flame (as a piece of thin newspaper would burn). The heavy end of the molecule is not so easily ignited, but it burns with a much more intense heat (as an oak log would). This heavy end of the gasoline molecule is responsible for the hotter, more powerful part of the combustion process.

Small aircraft are constructed as very weight conscious vehicles. That's because their somewhat weak engines often have difficulty taking off with any extra weight. To help reduce this weight problem, aviation gasoline's are blended with no heavy molecule end. This makes a gallon of avgas weigh substantially less than a gallon of ground level fuel. Since small plane engines turn very low rpms and produce so little power, the omission of the heavy end is not a horsepower issue. However, for high output racing engines, there is defiantly a compromise in power. Despite the fact, many high powered engine owners experience the desirable cooler operating temperatures that avgas offers. In addition, some blends of avgas will quickly separate from some oils used in premix situations.

Despite all this bad news, running avgas (accepting the slight power loss) is usually a better choice than burning down a high output engine on regular pump gas. In this situation, the best choice is usually a 50/50 mix of pump and avgas. That provides "some" heavy molecule ends for the engine.

 

Lots of threads on this topic, search.

 

On stock engine, hell no, 13:1 , yes.

 

I did the word search and wow, thats alot of info. I'll use that again. Here is the answer I have sorted out of all the replies. If you have to run it, it is recommended to blend it 50-50 with regular pump gas. There are alot of stories about it being bad for your motor, but very little evidence of this. The conclusion...there are better fuels out there that have a molecular design for the types of motors we have........Did I get the answer close to correct? Thanks for all the input, jk

 

SHAV0 KNOWS WUT HE'S TLKIN BOUT ON THIS ONE.... I CAN TELL BECUZ I COULD BARELY COMPRIHEND WUT HE WROTE

 

I run 110 in my banshee w/ amisoil or klotz w/ 93 , the 110 is maily used when you have cool heads

 

I have ran the Av Gas for years with no probs.
It is more consistent than pump fuel and resists detonation very well.
235lbs of compression in the 250R, and absolutely no detonation. Also ran it in my high compression 330R for about three years.

May have to re-jet for it, and it can cause sluggish throttle response, but a timing advancer takes care of that.

A lot cheaper than race fuel too.

 

my friends races dirt bikes and hes throw about 4 G's into the motor he racesall over the place he had everything possible done to this thing its sweet he has a track in his backyard and everything he dads buys the aircraft gas he said its lik $40 a gallon or sumthing

 

I just love this topic. Anyone who runs a higher octane fuel/gas than is needed for their engine is just pissing away his/her money. The thought that running "race" gas in a stock compression engine is going to give out more power is foolish. All the octane rating of any fuel amounts to is its resistance to burning. If the engine doesn't have sufficient enough compression, (not meaning your engine needs a rebuild either) just that for example an engine with 8.5:1-10:1 compression will see no benifit at all from "race" gas. Good ol' 90-94 octane pump gas is plenty good enough. The only exception to this rule is a stock compression engine that has had its timing advanced to the point where "race" gas would be needed.