AV-GAS vs RACEGAS

**theeechozen1** · 03-05-2003, 05:06 PM

just wondering what everyone thinks, whats the difference? witch is better? is it avalible in your area?
They recently installed a self serve station at Falcon Field airport by my house---you can pump it yourself and its only 2.10 a gallon!!!! :evil: 91 octane in my area is anywhere from 1.93-1.99 gallon (I have to run it in my car cause its supercharged)..............I think I might have to switch to AV!

**FullBore** · 03-05-2003, 05:45 PM

I think I've had a play with AVGas before, I found it gives 2-Strokes a good kick up the butt, I can't remember much else.

Nat

**Billy Golightly** · 03-05-2003, 06:59 PM

Oh boy...I'll have to watch this thread pretty close to prevent what happened last time this thread was started (Nearly 9 pages of debating that almost split the board up) Not your fault though, so don't worry about it. I just encourange everyone to make their opinons in a nice and orderly way.

**theeechozen1** · 03-05-2003, 07:11 PM

:oops: my bad! My friend told me that there is additives in AV-GAS that is not good for bikes or cars but is good for aircraft, Another friend told me that it's just a more pure form of gasoline with higher octane that burns cleaner....................I have no idea, they both seem to know there stuff :|

**Billy Golightly** · 03-05-2003, 07:16 PM

Its ok, you didn't know. Most of the people where arguing over how av gas was designed for high altitude uses, that the lead in the fuel isn't good for the engine, ect ect. And then there were those arguing it was fine. I don't mind if people reply to the post, just as long as it stays civil.

**DixiePlowboy** · 03-05-2003, 09:50 PM

I've ran 100LL Aviation in two high compression 200X's and an '86 Tri-Z with no problems. It's 6 miles to the airport, but 20+ miles to the nearest race gas pump, or else I would use the race gas exclusively.

**wizzard** · 03-05-2003, 10:41 PM

I've been running av-gas in my tecate for a while. the bike has never had any problems and it burns very clean, but i read somewhere that this fuel is designed to make power at low rpm's and high altitude, (makes sence, doen't it) so i think i will try a combination of C14 (114 octane race fuel) and pump gas on my next tank. i will mix it so it comes out to about 100 octane and see if this makes any difference. if it does it will probably be in the higher rpm range. i'll let everyone know.

**Kilborg** · 03-06-2003, 01:45 AM

i was in the same boat dixieplowboy...i ran av gas in a high compression 200x sometimes.

**Dan Tenn** · 03-06-2003, 10:12 AM

Im not sure about race gas, but AV gas has Lead added to it, since alot of aircraft are vintage, and still run the non hardened vavles. The LL in 100LL Av gas stands for Low Lead. The lead helps keep the valves cool, and gives them a little additional lube. I would see no problem running this in a trike, I used to run it in my sled. However, I would not use it in a newer vehicle with a catalytic converter. I am not positive, but I have heard that the lead will plug the converter, and cause all sorts of other problems (computer doesnt get proper readings) It may mess with the O2 sensor also. Sometimes higher octane doesnt necessarily mean more power. We built a 540ci BBC, and took it to the dyno. They always use race gas the first few pulls to make sure that there is no detonation from too high of compression, then slowly mix in premium 91 octane until its all 91. This motor made an extra 15 HP on 91 rather than on race gas (590-605 HP). I thought it was goofy, but the tech said that it is pretty common depending on the setup. He said if you dont need it to control detonation, its just a waste of $$$$. sorry for the long post, just wanted to get the fire burning.

**balelorf** · 03-06-2003, 12:37 PM

Race gas will usually run cooler for most high compression setups, because of the detonation issues as well as others that I once had explained to me but forget now. Also if you know how much compression you actually have, here is some information I plagarized from a shop that sells after market heads for Banshee's as far as compression vs. octane:

210lbs - 115
200lbs - 112
190lbs - 110
180lbs - 105
170lbs - 98
160lbs - 91
150lbs - 91

Here's a chart for the TRX:
http://www.macdizzy.com/compress.htm

**Curtis-Tecate3** · 03-06-2003, 03:29 PM

Oh No, Not this one again.....
Just kidding. Mike in Ft.Lauderdale will chime in on this one as well I am sure since he builds Hi-Po Aircraft engines.

I have run 100LL Av-Gas in everything from my Tecate to my 200X to my Racing Go-Kart with zero problems. I also run it in my Airboat with an aircraft engine. I also do some work with a friend that builds SCCA Formula Race cars that run 4cyl. Ford engines and we run 100LL in them when rules permit. We have dyno tested 6-7 different fuels on these cars (Cam2, VP, Sunoco) and 100LL beat all of the purpose built race fuel blends. Mind you these fords are fairly mild compression motors though. DO NOT run this fuel in your street car if it has a catalytic converter. The lead will kill the Cat in no time.

100LL is 100 Octane Low Lead Aviation Fuel and is normally Blue in color. The "Low Lead" is a little misleading though as it is actually a high lead content when compared to old leaded auto fuel.

If you have access to it I say go ahead and run it. But dont waste your money unless your bike pings (Detonates) on 93 octane....

Curtis.

**theeechozen1** · 03-06-2003, 03:36 PM

But for my stock 250r I figure that 10-20 cents more a gallon is not bad for a little extra kick, but I don't know how much of a kick it actually gives it. I'll get a race jug full this weekend and run it to see if I notice a difference.

**Tri-Z 490** · 03-08-2003, 02:10 PM

Yeah I have heard the same thing that the lead has a chemical reaction or something with whats in the cat and will clog it up. Thats what happend to my friend that works at an airport he thought he was getting off easy by putting that in his tank but he has to buy a new cat after awhile.

**ATC crazy** · 03-08-2003, 03:31 PM

I know this is a little off the subject, but will AV gas, or racegas run in my stock Foreman 450S? (100LL or whatever?) What if it had a high comp. piston? (10:1? 11:1?) I was just wondering because I plan to modfiy it some (or leave it stock) and do some XC or Hare scrambles and I have no experience w/ anything but pump gas.

**HemiChallenger71** · 03-08-2003, 03:59 PM

I liked the compression vs. octane chart. I'm not so sure about it though. My piece of trailprotrailprotrailprotrailpro dodge shadow pulled 160 PSI of compression in 4 cylinders and 180 in two others. I run 87 octane gas, and get no spark knock, and no cylinder damage (I just did the head gaskets). Mind you the engine has 120,000 miles on it also, and didn't have carbon built up in the cylinders (I made sure of that in the few days before). What do you guys think of that? Maybe the liquid cooling keeps the knock away,but i run a 190 thermostat also.

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