Aviation Gas

Has anyone used av gas? It seems that 100LL, is the rough equivalent of 106 octane race fuel, but with more lead. It works out quite cheap, but are there down sides? It's to run in a flathead with 10:1 comp, so if you can run it, are there any additives that would need to be added and if so what?
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its not a great idea. I tried it a couple of years back when I was runnin my harley in a dyno comp. I lost 14 hp when I switched from hi-test to av-gas.....something about the stuff they do to it it run up high

 

about 20 years ago , a ran av gas in a `66 chevy impala with a 283 because it was free. i didn't think it ran worth a crap and quit using it

tried car gas in an airplane ,seamed to work fine...but it kinda scared me and didn't do it again

 

Had some tard asked if I had to run aviation fuel in the beater.....Told him I was on my way to the airport right now. Some people's kids.

 

Back in 1966 we mixed 115/145 (Av-gas) with Mo gas (regular) when I was in the sevice (USAF) worked well in my flathead! Be carefull with your exhaust valves!!

 

I ran 5 gallons per tank in a SBC. Needed the octane and lead for small chamber marine heads without hardened valve seats. It kept it from detonating and didn't hurt the valve seats, but it never ran as good as it should have.

 

100LL is 100 octane.

 

The 100LL stands for low lead >>>>.

 

Ran a 50/50 mix in a bbc back when the octane rating started falling. It was an 11-1 motor with ported heads, roller cam on nitrous.

 

From what I've been told about avgas it seems it burns slower that "regular" gas. If you need to give your flattie a boost why not try mixing some VP C12 race gas. I've been using it for years in a motrcycle engine at 14:1 comp. with absolutely no ill effects.

 

Aviation fuel has more aeromatics (sp) and that is why it has slower throttle response than automotive fuel.

it seems that the aeromatics (additives) cause this..some of the additives are to keep it from vapor locking and somewhat change the specific gravity of the fuel.

smells great though

 

Avgas has different evaporation and burn characteristics than automotive gas. Its meant for high-altitude use at near-constant rpm. I've used 50/50 with an older high-compression motor with no ill effects.

http://74.125.45.104/search?q=cache...apor+pressure+100ll&hl=en&ct=clnk&cd=10&gl=us

Haven't found a MSDS for regular car gas yet.

Found one:

http://74.125.45.104/search?q=cache...oline+conocophillips&hl=en&ct=clnk&cd=3&gl=us

 

Higher octane fuels burn slower, that is why it is used to prevent detonation. Engines that do not require the high octane will LOSE power running it unless the timing is changed to compensate for the slow burn. The lead will help those who do not have hardened valve seats, but will not show any benefit elsewhere. I had a 600 hp. BBC that I watched get broke in and dynoed after being put together. I was broken in on race gas to be sure it did not detonate during break in. Max hp on 110 race gas was 583. Slowly mixing in 91 octane pump gas until we were sure it would not detonate and it made 603. Of course we may have gotten to 600 with race gas by adjusting the timing, but this was for a street car, and was to be run of pump gas so that is where the timing was optimized. Long story short, if you need 100 octane fuel (there also is 110LL), go ahead and run it. The lead won't hurt anything except mother nature. If you can use 91, you're wasting money and HP.

 

found this for ya
I am going to attempt to address the controversy of aviation gasoline verses racing gasoline for use in race cars. Some racers use aviation gasoline which is fine for some applications but does have shortcomings. There are several grades of aviation gasoline (avgas) that we must identify before going any farther.
1. Avgas 80/87: this product is used in low compression ratio aircraft engines, contains little or no lead, is red in color, and should not be used in any automotive engine due to a low motor octane number of about 80.

2. Avgas 100/130: this product that can be used in some automotive engines. It has both research and motor octane numbers slightly over 100. Avgas 100/130 is green in color, contains four grams of lead per gallon, and is becoming harder to find.
3. Avgas 100 LL: the LL stands for "low-lead" which means two grams per gallon, low compared to the avgas 100/130 that it was designed to replace. It has research and motor octane numbers very similar to the 100/130 product previously discussed. The color is blue. This product sometimes has a high level of aromatics which can contribute to lazy throttle response and dissatisfaction of the consumer.
4. Avgas 115/145: this product was developed for high performance piston aircraft engines used in world war II and in the Korean war. It is very hard to find anymore due to lack of demand although it is of very high octane quality. The color is purple.

The remainder of this discussion will assume that our basis for comparison with racing gasoline is avgas 100/130 and/or 100 LL since they are both available and have acceptable octane quality for limited applications. When the word "avgas" is used, it will refer to avgas 100/130 or 100 LL.

Avgas is less dense than most racing gasolines. Instead of weighing about 6.1 to 6.3 pounds per gallon like racing gasoline, it weighs 5.8 to 5.9 pounds per gallon. The racer must compensate for this by changing to richer (larger) jets in the carburetor when changing from racing gasoline to avgas.
The other major difference is octane quality. Avgas is short on octane compared to most racing gasolines. Many racing engines with "quick" spark advance curves or with no centrifugal advance have more spark advance at low rpm than avgas and some racing gasolines can handle. The result is detonation, especially during caution periods in circle track racing because all of the spark advance is "in", rpm is low, and part throttle air fuel ratios are too lean for the operating conditions. If the driver does not "work" the throttle back and forth, pistons can be "burned" which melts away part of the aluminum piston material. Inadequate octane quality is one of the quickest ways to destroy an engine. Pistons can be severely damaged during one acceleration where detonation is present and the racer may not know what is happening until it is too late.
For maximum performance and power from a racing engine, racing gasoline will normally provide better performance than avgas. Avgas can be a good gasoline for some applications, but since most racers do not know the octane requirement of their engines, they would be better off with a "real" racing gasoline that will give them the overall resistance to detonation that they need to protect their investment. If someone has spent from $15,000 to $50,000 or more on their racing engine, it is foolish to cut corners on gasoline be sure you have a gasoline with adequate octane quality

 

We used 100LL for 3-4 years in the race cars because racing fues was $6-7 a gallon at the track. But one day I took the truck and trailer down to the airport to fill up 4- 55 gallon drums and they would not sell it to me. They said that they were not allowed to fuel jugs anymore because of the road tax not paid on it.. Are you guys able to fuel cars at the local airport??

 

That's great, thanks Von Rigg Fink. Are there specific implications when using it with a lower rpm flatty?

 

I've run it in circle track cars for years with no problems. It will run good up to about 12:1 compression ratio.

 

I used to work at an FBO at the Georgetown Municipal Airport (TX) in highschool. One of my duties was to sump the fuel trucks every morning to get out any condensation that would form over night. The fuel was always fine so I used to put it in my 300 inline six powered F100. An old timer at the airport told me to mix it 25-30% with regular fuel, and to crank the timing up a bit... adjust the mixture and go. I did it and felt a really noticeable difference. Not only that, but free fuel was always a plus. I did run it pure once... I was broke and late for a date... you all know how that is. The truck ran fine and I felt it pick up a little more running it pure. I don't have dyno numbers to back up my story, just seat of the pants. I DID feel a difference, but i'm not going to put a number on it.

Some smaller airports will still sell it to the public, but for FAA records they usually require an aircraft tail number. Thanks to the 9/11 idiots. Another reason I quit flying Cessnas after that... too much red tape.

 

Is Gaylord really your name?

 

Aren't those Av Gas octane ratings at 10k feet, though?

Things are a little different here on the ground.

~Jason

 

the purple stuff..i remember that! it didn't do much for my Honda 90

 

I was running 100LL in my 4 cylinder G/GR at Bonneville. Stuck at 139mph on a 140mph record. Went to ERC110 for record attempt and ran 141mph 142 out the back door with no other change. Put new plugs in it and went 142 on return. Decided ERC 110 was better than 100LL.

 

A common poor man's racing gas was to mix the following in a 55gal drum:

25 gal AMOCO 93
25 gal 100LL
5 gal Tolulene

Love the smell of avgas though...

 

For a real kick, sub 1 gal og Amoco 93 and 1 gal of 100LL for two gallons of kerosene!

Whoo hoo!

~Jason

 

Found here: http://bbs.clubplanet.com/cars-bikes/141798-how-make-relatively-cheap-octane-boost-race-fuel.html

Be careful with this shit - you'll put yer eye out, kid.

Or probably melt a hole in your piston, anyway.

~Jason

Homebrew Gasoline Octane Boosters

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Editor's note: I would NOT suggest that a person use the following fuel mixtures without considering the detrimental effects on your engine, vital engine components (O2 sensor, etc), and other potential damage. That said, the information is interesting.
Original published in:

GS-Xtra
1213 Gornto Road
Valdosta, GA 31602
(912) 244-0577

Editor: Richard Lasetter, president Gran Sport Club of America (GSCA)

Formula #1 - Toluene
R+M/2.........114
Cost...........$2.50/gal
Mixtures with 92 Octane Premium
10&#37;...........94.2 Octane
20%...........96.4 Octane
30%...........98.6 Octane
Notes: Common ingredient in Octane Boosters in a can. 12-16 ounces will only raise octane 2-3 *points*, i.e. from 92 to 92.3. Often costs $3-5 for 12-16 ounces, when it can be purchased for less than $3/gal at chemical supply houses or paint stores.

Formula #2 - Xylene
R+M/2.........117
Cost...........$2.75/gal
Mixtures with 92 Octane Premium
10%...........94.5 Octane
20%...........97.0 Octane
30%...........99.5 Octane
Notes: Similar to Toluene. 12-16 ounces will only raise octane 2-3 *points*, i.e. from 92 to 92.3. Usually mixed with Toluene and advertised as *race formula*.

Formula #3 - Methyl-tertiary-butyl-ether (MTBE)
R+M/2.........118
Cost...........$3.50/gal
Mixtures with 92 Octane Premium
10%...........94.6 Octane
20%...........97.2 Octane
30%...........99.8 Octane
Notes: Oxygenate. Very common in octane booster products. Has lower BTU content than toluene or xylene, but oxygenate effect makes the gasoline burn better and produce more energy.

Formula #4 - Methanol or Ethanol
R+M/2.........101
Cost...........$0.60 - $1.75/gal
Mixtures with 92 Octane Premium
10%...........94.3 Octane (Methanol)
10%...........94.7 Octane (Ethanol)
20%...........Not Recommended
Notes: Methanol is wood alcohol. Ethanol is grain alcohol and found in Gasohol in 10% ratios. Both alcohols are mildly corrosive and will eat gas tank linings, rubber and aluminum if used in excessive ratios. Main ingredient in "Gas Dryers", combine with water.

Formula #5 - Isopropyl Alcohol and Tertiary Butyl Alcohol
R+M/2.........101
Cost...........$0.60-$1.50/gal
Mixtures with 92 Octane Premium
10%...........94.5 Octane
20%...........Not Recommended
30%...........Not Recommended

Notes: Similar to Methanol/Ethanol. Isopropyl Alcohol is simply rubbing alcohol.

Sample Mixture
To make your own octane booster, it is easiest to make up a large batch, and then bottle it up in "dosage-size" uses.
Below is the basic formula of one of the popular octane booster products. To make eight 16 ounce bottles (128 oz = 1 gal):

100 oz of toluene for octane boost
25 oz of mineral spirits (cleaning agent)
3 oz of transmission fluid (lubricating agent)
This product is advertised as "octane booster with cleaning agent *and* lubricating agent!". Diesel fuel or kerosene can be substituted for mineral spirits and light turbine oil can be substituted for transmission fluid. Color can be added with petroleum dyes.

 

Little history on 100LL .... not that it matters. In the mid 40's through the mid 60's planes were being built to run on 80 octane... by the late 60's and 70's most planes being produced converted over to 100 octane. In the mid 80's gas companies started to phase out 80, and started only selling 100... but the octane boost had poor results in the older aircraft and decreased the lives of the engines people were pissed. But the gas companies didn't want to produce two types of gas so they came up with 100ll so it would run alright in both 80 and 100 octane specific engines. You can't get 100 octane avg in the states anymore but you can in Mexico!

 

Back in the day ..... 1962-63 had a 57 Ford 312 with "stuff" and when we went to Atco Dragway we used straight 115/145 in it. Ran like a scalded dog but adjustin' the valves with the motor runnin' was a bitch ... fumes stung the hell out of yer eyes ... Never had any adverse effects on it though ..

 

Me and my ol man use av gas in our drag sleds. We dragrace snowmobiles, and in our 700cc mod sled we run leaded Av gas mixed with a bit of 110 added. Its good enough to hit 112mph in 500 feet runnin 192 psi heads and 8400 rpm.

 

**** Wasn't that the cats name on meet the parents Gaylord Focker??? >>>>.

 

I must say after working at a FBO for 3 years and getting my A&P My personal experience with running AVgas. Has been great I run it in my 70 mustang and 64 impala with out a hitch. Both cars idle smoother I have done no changes in carb or timing, temperature runs 15 to 20 degrees cooler when runnning on avgas I usualley run it half avgas half mogas, have ran it straight only thing I noticed when running straight is harder to start. In cold weather, in my mustang I was able to advance the timing wich of course responded with more power. My experience may not have been the same as others But have beeen running this stuff for 3 years flawlessley and would recomend it to anyone however I would not try to cut corners and run it in a $15000 race engine if you could afford a engine like that and a car worthey of running it why put cheep fuel in. (You get out what you put in )

Thanks 64imppy