Thread: airplane fuel

Tweet

Hey guys i have a question regarding airplane fuel. i can go to the local airport and buy 100 LL for $3.00 a gallon. thats a steal compared to premium at around $2.95. i have heard some people say that airplane fuel is bad for runnign in cars. is this true and if so what will it damage. i do have hardened valve seats for un-leaded gas.

Octane that you don't need is money wasted. Avgas in itself is no harder on a car than any other gas. There is a legal point, though---avgas has no road tax added, so it's illegal to use on the highway. It's also less volatile, to prevent it boiling off at high altitude. This may affect how it works in your engine, making it run lean.

I heard aviation fuel will melt the reed valves in a 2 stroke dirtbike, something to do with it being made for high altitude. I'm not sure about putting it in a streetrod, might screw up the carburator or something. Reed valves are made out of fiberglass or some carbon fiber, so who knows what it will do to rubber seals. That's just what I heard though, from someone who ran it and had that problem. I haven't really researched it. Maybe someone else knows more about it on the forum.

Okay, I've been staring at the monitor for a half an hour. Trying to decide whether to start a fire storm or answer this . Let me ask you guys a simple question first. Because you are above average in these fields, What is 110LL av gas? Denny, Dave, Tech, Pat, and those who we trust, need to jump in and answer these questions. I am a bit gun shy right now, I need to help out and not start a troublesome post. 100LL is the same thing that comes out of the farm tank that everybody gets their fuel from at the pump. No magic, just different add-packs from the supplier and the distibutor. The biggest change compared to your fuel is an additive (non sodium based) that allows air cooled engines to not suffer a heat related octane drop from altitude change relationship as the aircraft goes through it's adjustment period in flight. Scared?......don't run it. Want numbers of several super comp and pro comp cars that win with no problems? And never see a problem but good performance? hhhmmmmmm.........by the way, with the numbers at your local race track going sky high ask anybody (dirt track and asphalt ovals) in the pits if they're using it or diluting thier fuel with it. It might surprise you. Gunks up or destroys the carb and other items?.....wow......It's still the same based petroleum grade fuel you get. Just not add-packed as you want. How did this person acquire this fuel with out an "N" number? Interesting situation there. Sorry, I'll go off under my rock and pop a cold one now.

100 LL is rated at 100 octane. Octane is a rating, not a tangible item. Just like inches, feet, farenheight, celius, centigrade etc. are a rating, and/or measurements. The LL just means Low Lead. And before someone gets all bent, yes, you can buy stuff refered to as an "Octane Booster". But you can get the same stuff just about any where, it's called kerosene. Yep, good ole kerosene, that will help dummy down that pesky pump gas, that detonates under pressure and causes pinging and damaged pistons. 80 Octane rated aviation fuel, which is red in color, is for the low compression engines. (Red is getting hard to find now, contains lead and is being phased out.) 100 is for the next step up in compression, (and is now only available in low lead) 105 is blue. Purple is 110 and clear is 115. If you can find them. And another side note, mix any two colors, and they will go clear. A safety precaution, if you should only be using the blue stuff, and somebody put in something less, you'll know to start asking questions before you take off. Ok, back to the original question. If you have a problem with detonation and preignition it will help. It won't hurt your pump, 'O' rings, gaskets, carb etc. (Can't put auto fuel through a planes system though, the additives will swell the "O" rings and seals, more so if there's alcohol in it.) The short answer, use it if you want, and if you need it. Guy's have been racing with it for years. It in itself, won't give you some big giant increase in power. The high compression engine that needs this stuff run on is where you see a power increase. And that's because of the engine and components, not just because of the fuel.

i have runned it for many years in all my cars .all big blocks up to 14.8 cr .i never had it do any bad thing,s. to my engines????????????? if you do not need 100LL hi octane then you should not run it . it is called LL low lead not NL no lead???? so how could it be hard on seats or valves ?????it must have some lead in it ? BUT there is no over the road tax so you can not pull up to the pump and get it . they will not sell to you if you run it on the road .one last thing is fuel is for air planes it has to pass what it is 100LL you would have a better chance of that .then what you would get at the gas pump for over the road use

i thought i wouldnt be able to get it so easy but i just go to my local airport pull up to the pump swipe my card and buy it. my arguement for the person(s) who told me that it wouldnt run right was the same as yours Nitro, that it is the same gas from the same tanks and the same trucks just with diffrent additives the reason i run it is bc my motor being an 11.5:1 motor seems to like it more than premium and at only $3.00 it is a better deal also it may just be me but out of the few times i have filled up with it the car has gotten better mileage

Put some of that avgas in your tank if you want, I did so some years back cause I ran out at my local field. Was driving an old '64 Corvair (air cooled engine). Thing rattled an' pinged so bad I didn't think it would make it to the station for some of that highway stuff.

the thing is if you do not have a hi CR engine 100LL it would be the last thing you would put in the tank

My buddy ran it all the time in his new Toyota pick up. He swears by it and it ran like a swiss watch.

good post denny ...the av gas will make them start hard in the cold ?i have been told of its lazy front molecules??? hard for me to say? i do not drive any thing in the cold and my cars have no chokes .i did use this stuff for over many years but stop using it .i could not pull up to pump it in the cars i run it in .but i can pull up to the 110 race fuel and pump it in .the thing is i could never see any dif in it from 110 race fuel to 100LL but run what you like but LL100 has work for me

Used to brew up a concoction of AvGas, unleaded and 104 octane booster for a bracket car, even snuck in a little bit of upper lube cuz of the old fear that Av Gas is too dry and will kill the valve guides. Anyway, with the right mixture it would come out to 103 octane. That was a bunch of years ago, gave up on it and went to race gas (used to be a dealer and sell it at retail). Usually sold enough to customers to cover my usage in the drag car. Got involved with the E-85 and E-90 ethanol about 5 years ago. Yeah, I know it's not as efficient blah blah blah blah, but our little group has two big blocks pulling over 500 horse on it and a Windsor that is running 440 horse, all RWHP numbers by the way, right off the chassis dyno. Maybe we're just on a lucky streak but after 4 years with it in cars have not yet lost a piston or valve or seen any wear other then the normal wear in these engines...... Don't think I'll be going back to gas anytime soon. Even running E-85 right out of the pump in two daily drivers now..... BTW, 104 octane for $2.20 a gallon ain't bad in my book....

Anyway, as for the Av Gas, I'd play with some blending between it and pump gas, maybe a shot of 104 Octane Booster when it's time to play serious. Get a fuel hydrometer and learn to use it. Don't take anybody's word for what comes out of a barrell or pump when you're "good engine" is at risk...

thanks for all the info form all the replys i have gotten i think im gonna keep running it the car usually ends up getting a mixture of 93 and the Av gas bc i cant always get to the airport to fill it up but so far it has been fine in my car and i love the way it smells when its burning haha

Originally Posted by tyler

thanks for all the info form all the replys i have gotten i think im gonna keep running it the car usually ends up getting a mixture of 93 and the Av gas bc i cant always get to the airport to fill it up but so far it has been fine in my car and i love the way it smells when its burning haha

yes that would be AROMA THERAPY it smells so good better is C16

If you have to go the airport to get gas, how about going to your speed shop to get some 104-107 leaded race gas. I used to mix that 50/50 with unleaded premium to make my '68 427 Vette run. Measured 11.38:1 CR.

Kitz