Airplane fuel

[Kingjoel]

A friend of mine has a 103 Harley dyna. I'm sure my 78 GS 1000 will smoke it. I thought a couple quarts of airplane fuel added in my fuel tank would give me a boost. Has anyone done this, and is there anyway it would hurt my bike?

[RichDesmond]

A friend of mine has a 103 Harley dyna. I'm sure my 78 GS 1000 will smoke it. I thought a couple quarts of airplane fuel added in my fuel tank would give me a boost. Has anyone done this, and is there anyway it would hurt my bike?

Won't hurt, won't help. AVGAS has no more energy per gallon than regular gas. Save your money.

[grcamna2]

I'm not sure AVgas will make your bike run better;depending on the CR that your bike has.High compression engines love high octane fuel as they don't ping/preignition like they do on low octane regular.I'm hoping to locate a place where I can purchase non-ethanol/Ethanol Free gasoline.I think 89 octane ethanol-free gas would be just right for my use.

[Kingjoel]

Thanks for your reply. Would 110 octane racing fuel be any different?

[timebombprod]

That thing will smoke it either way he will just get a quick jump in front for a bit

[RichDesmond]

Thanks for your reply. Would 110 octane racing fuel be any different?

No. The only fuels that will make more power are special oxygenated ones, and you need to rejet to see any gains.
The advantage higher octane fuels have is that they allow you to run a higher compression ratio and/or more ignition advance. Just dumping high octane fuel into an existing engine with no mods does nothing for power.

[chuck hahn]

Octane means diddly squat for power added or power lost.

What is octane rating? Octane rating is the measure of a fuel's ability to resist "knocking" or "pinging" during combustion, caused by the air/fuel mixture detonating prematurely in the engine

[Grimly]

I ran an old Mini van on avgas for a couple of years, simply because it was free.
It did nothing for performance, nor did I expect it to, but it definitely ran smoother.

[Cipher]

i ran an old mini van on avgas for a couple of years, simply because it was free.
It did nothing for performance, nor did i expect it to, but it definitely ran smoother.

free avgas??

[slayer61]

The often unmentioned advantage to real race gas, is it's ability to store well over time. Normal "gas" rots in a short time. Real race gas remains stable and usable for long periods of time without the need for fuel treatments of any kind.

[Brendan W]

Avgas has lower vapour pressure. Doesn't flash off as fast as Mogas.
Vintage aircraft, around here, running Mogas are restricted to 5000ft altitude to prevent vapour locking.

[Who Dat?]

The advantage higher octane fuels have is that they allow you to run a higher compression ratio and/or more ignition advance.

The part that actually provides the power is the higher compression. However, higher compression means more heat, and that tends to light the mixture before the spark. Higher-octane fuel resists that heat, which allows you to use the higher compression. Part Two: higher-octane fuel is harder to ignite and it burns slower. You need to advance the ignition timing to compensate for that.

Just dumping high octane fuel into an existing engine with no mods does nothing for power.

If anything, it will REDUCE power. Higher-octane fuel (I refuse to call it "Premium") actually contains fewer BTUs per gallon than lower-octane fuels. Then, referencing the points above, note that along with the lower energy content, add in the slower burning, which won't be done in time to support peak pressure, you will get less power from your engine.

[bonanzadave]

free avgas??

I had drained 10gal to change a Bonanza fuel cell. Owner didn't want it back so I ran it in my various lawn ICEs. Everything use to start on the first pull with 87. Not the case with the 100LL.

[hank2]

I'm not an aviation guy, but I believe there are a number of grades of leaded aviation piston engine fuel. The common one was always 100LL , "low lead", which actually has a good bit of lead at about .5 gm/liter. I have heard of a no lead Mogas, which is more like 90 PON zero ethanol pipeline gasoline. I recall some folks using the 100LL in built high compression cars and bikes at least 50 years ago. I believe most quit it due to the Reid evap formulation being optimized for altitude in Aviation fuel. Maybe not so good for cooler temps on the ground?

The highest octane auto fuel in the US. these days is 90 PON, was 91 until a couple of years ago. ( Research + Motor rating numbers, divided by 2). Anything higher is ethanol dosed after the pipeline or a race gas specialty. I'm fortunate to have about 5 stations that sell zero Ethanol pipeline reformulated not too far away. Some are 89 PON, others 90 PON. My GS seems to run fine on them. No trace of pinging.

edit: I didn't see Brendan's previous post about the vapour pressure of Av gas.

[wymple]

We had a gas back in the 90's around here called "Turbo Blue", and it was listed at 104 octane. A bit pricey. My GS1100 EZ would ping a bit in hot weather so I would put a gallon of it in & top off with regular. It stopped the pinging cold. Stations carried the stuff for the stock car racers who push the compression pretty high.