I acquired 35 gallons of 100 octane fuel today. Its aircraft fuel. Anyway, can I safely run this im my 2000 Scrambler and Trailblazer? Will the jetting be ok? They are both stock topends and I run Klotz through the injector system. Will this work? As it is, I currently run 92 octane with an octane boost. So, I have 35 gallons of some pretty bad stuff and want to use it. Any advice? Thanks and God Bless America.
PD

 

It should be fine to run in them as long as it is good gas an not old gas going bad. You might even get a proformnce gain from it to. I have use 100 avation fuel in my TB but with my mods I have found out that I need to run 110 in it an when I talk to Darel at HPD he told me that they have found out the same thing so I would go ahead an use it.

 

From my understanding aircraft fuel has a different make-up and shouldn't be used in ATV's. I am sure there has been a lot of discussions previously. if you do a search I am sure you will come up with some good information.

 

Ok, let me see if I can explain the difference in fuels:

Aviation gasoline (or "av gas&quot is blended specifically for use in small aircrafts. 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. Av gas 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 aircrafts 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 av gas 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 atv racing engines, there is definitely a compromise in power. This, despite the fact that many atv owners experience the desirable cooler operating temperatures that av gas offers. In addition, some blends of av gas will quickly separate from some oils used in premix situations. For the above reasons, I do not recommend the ongoing use of 100% av gas.

Despite all this bad news, running av gas (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 av gas. That provides "some" heavy molecule ends for the engine.

I hope this helps solve the problem.

Scott [img]i/expressions/face-icon-small-happy.gif[/img]

 

you probably want have any problems with the trailblazer but... the scrambler i can tell you it will mess your reeds up if they are still the stock reeds. trust me i done been there[img]i/expressions/face-icon-small-smile.gif[/img]

also if you do decide too run it i would recommend turning your oiler up a bit since AV fuel is a much drier burning fuel.

 

Thanks for the replies. The guy I got the stuff off of said the gas was awesome in 2 strokes. But now Im worried. Anyway, it was free so no big loss. If anything my lawnmower should do wheelies!
PD

 

I would not use aircraft fuel. It has way too much lead. 100LL aircraft fuel has about 5 times more lead than the old low lead fuel that used to be available for cars. The lead is how it achieves the octane rating. All modern engines have been designed to operate on no-lead gasoline. They have very tight clearances. Aircraft engines were designed 70 years ago and have very loose tolerances and two plugs per cylinder. Running a very high lead gasoline could foul plugs and leave other deposits that could foul the tighter rings in modern engines. It should be noted that 2-stroke Rotax engines used in Ultralight aircraft do occassionally burn 100LL when pilots need to fill up at an airport, but owners try to avoid this. Remember also that extra octane beyond what the manufacturer recommends doesn't produce any extra power. Many two stroke guru's recommend using the LOWEST recommended octane to achieve the best performance.

I'd dilute the AVgas with regular 87 Octane and burn it off in a tractor or give it to someone with an antique car where the lead would be benefical. Old engines need lead to lubricate the valves.

 

I am not a fuel expert, but I did stay at a Holiday Inn Express last night. :-)

I believe you are thinking backwards about octane. In a motor, if you run too low an octane gas, the motor will knock. The knock is the fuel/air igniting too early, ie before the spark plug fires. In other words, the fuel air mixture is too flammable. Increasing the octane of the fuel decreases the flammability and the speed it burns.

So the question you may be asking is why do perfomance motors need hi octane? In short, hi performance motors have hi compression ratios. The higher the compresion ratio the higher the octane needs to be. Therefor, many people accociate hi octane with hi performance.

Your motor will have its best performance with the lowest octane the motor doesn't detonate on.

Your milage may vary.

Charlie

 

That night at the Holiday Inn was worth it.

Also hi-perf machines use the higher oct fuel because it burns cooler. But, the statement "do not run any higher oct gas than what you need to prevent detonation" is correct.

 

boxofrokx is exactly right,
Anyone running stock 400's do not run high octane fuels unless you have high compression motors. The high octane fuels burn too slow for the motor to cool down and will actually cause failure that appears to be detination (actually it is the exact oposite). Too many people believe that higher octane fuels magically make machines run better. The lowest octane fuel you can run without causing detination is the best fuel to run. Why? Because it burns faster and is more explosive. That is why you have to run race fuel in NOS usage. It slows the NOS explosion in the combustion chamber to a safe level for the engine. When I'm not wheelin' I drag race cars for a hobby and have to laugh at these younger kids who put TurboBlue or C12 in their '94 Probes (stock) and think they just created a 1/4 mile monster, LOL. What they are really doing is slowly but surely taking the rings out of their cars and wondering why it smokes like a Top Fuel dragster cleaning and heating its tires. Yeah it sounds cool to run race fuel in your machine but it is not helping any unless you're running it for the right reasons.