A question for aviators and progesssive thinkers- Av-Gas

Those of us with N numbers, would have trouble pulling up to the 100LL pump in a hot rod.
Local yes, but cross country no way.
I wouldn't set one of my cars up for 100LL, and I have a pump in front of my hanger.

In town there was an old crop duster that ran 100LL in his van.
I saw him almost every morning at the doughnut shop.
His van would be idling (a/c for dog) and you could smell that wonderful smell of AVgas.
He said he always ran it because thats what he had on his strip.
I don't know what he did to run it, but he was old as dirt and his van was about a '86.

 

Had my own inground 300gal tank out at the muni strip in Kodiak. My daily was a 74 CJ5 with an LT-1/M-21. Two tanks - I'd fill each halfway with high-test and then top them off with AvGas. Worked well, although AvGas is technically a little "dirtier".

dj

 

So the basic concensus is that you can run it no problem if you set your carbs up right. Never the less it is not legal to buy or sell it for automitive use, or for a rodder on a cross country run it is basically unobtainium.

Someone actually dropped me a note with a concern about the federal law concerning leaded gas on the highway and a blue gas leak. I guess the fine is pretty stiff like in the neighborhood of 25K.

I never could get the it will burn your engine up thing. I mean an internal combustion engine is an internal combustion engine, right?

On a side note when I was up at the property cleaning up storm damage last week I noticed that the only gas station in town only had one grade of gasoline, low grade. I am going to have to store good fuel for if or when someone comes to visit. Guess I'll get a drum and a pump.

 

Back in the mid '70's, we use to run a 50/50 mix of Av-gas and premium for the boost in octane. The motor was an 11:1 454, Airflow research heads, solid roller cam and a Dominator. The has had multiple nitrous units.

 

No place that sells av gas will despense the fuel into a car because of the tax/ lead restrictions. However, most places will despense fuel into (trailered) boats (restrictions don't apply) or proper fuel containers.

Bring one of those big, plastic race gas containers and tell them the fuel is for your boat. Most places won't have a problem with that. I work at a flight school and we buy fuel from the place right next door. I see boats and containers filled there regulary.

 

One of the items in the Federal Clean Air Act in 1996 includes the ban of Leaded Fuel used in any vehicle to be operated on Public Highways. 100LL AV Fuel is Low-Lead, NOT- NO Lead, so your Blue Fuel is out. In fact under the Clean Air Act, the EPA put in place standards to reduce toxic air from mobile sources too. This includes but not limited too - "gas containers" . Our good friend Benno asked specifically about operating his hot street car on this fuel, not just running the fuel. I'm not trying to start a firestorm, just dont want any members to have any legal issues here due to misinformation. TR

 

The times, they are a'changin..........there is a significant push going on from the enviro people to eliminate all lead from avgas. While some aircraft engines currently in service can use NON-ethanol laced auto fuel, a substantial number cannot and there currently is no solution in sight.

The term LL (low lead) is a relative term. It is "low lead" compared to the earlier 110 and 130 octane avgas that were phased out, but is higher in lead content than typical leaded auto fuel.

As for 100LL's tendency to foul plugs, I have owned a few Lycoming powered aircraft (0-320/0-360/IO-320) and they ALL would foul plugs while taxiing if I did not aggressively lean the mixture. I do use in my 'airport tug', a hydrostatic drive lawn tractor with an 2 cyl opposed Lausen (or Onan, I can never remember which). I have been doing that for several years with no ill effects. The thing I really like about the avgas, for both my plane and the tug, avgas doesn't deteriorate in the tank as far as I can tell and is always 'fresh' and ready to go.

Ray

 

Ran it in my 13/1 offshore outboard yrs ago and did it all day every day for a whole summer of boating fun. It will run but not outstanding. We were winging ours at 6500rpm but the fuel is designed to run in "Thin Air" or at Altitude....not sea level so it takes some tweaking of the carb. With todays technology why if you don't mind my asking do you need 12/1 on a streetmotor? I have 10/1 now and make a hair under 500HP and similar FT lbs of tq... Thats more than enough to blast 75 mph under 3K rpm on the highway safely and I'm not afraid of much pulling up next to me come to think of it....I'd think about making that baby run on the lowest octane pump piss you can get your hands on...Thats the ticket.

 

In general, it is too much trouble for everyone to acquire and run AV -gas. Build a relationship with a good racing fuel distributor and buy it by the drum.

 

I think I'm pretty progressive, I just put diesel engines in everything. Now I can burn all the JP-4 jet fuel I want. I can also run on sunflower oil also.
http://m.flickr.com/#/photos/36589379@N08/5871150341/

 

Wow sure glad I read this thread! I just got back from the lake with my 327 11:1 powered boat, which I run on 100LL, straight, boy does it like it. I also add a gallon to my coupe every time I fill up, it appreciates the lead. Wouldnt want to forget the Harley, you guessed it I also add a little 100LL everytime I fill it. And just to make it OK I also use a little in my Luscombe, although the A65 runs fine on unleaded. Screw the feds they can't find their own asses with both hands. The local FBO sells more Avgas to off field users then we do to aircraft, go figure. Current cost $5.25 a gallon, cheaper than Torco here. Forgot too mention I have been using since the 80's so I am not worried about it harming anything.

 

Birdman
I have an SBC that makes 406 and 444 at the wheels on pump gas. But that is not the point.

I also have a very hot Olds mill that is an old engine with history. I could lower the compression but I do not want to ruin the integrity of the engine because of its history. I figure that I am not the only one on here that is in the same situation.

I have come up with a solution for my particular situation I was just exploring another avenue for those who were interested. That and to dispell an old myth at least in my own mind.

I actually thought of an older just engine and run it on kerosene (low grade diesel).



I had a friend that aquired a jet engine from gawd knows where back in the '70s. He was into the whole experimental airplane thing. He always said that ti would fly on anything that would burn.

NMorris
I have been able to buy race fuel by the drum since I still lived in the washington valley, a very long time ago. the problem with buying fuel by the drum is that it would confine you to a trip that only took half a tank of gas.

I guess one could get a trailer to haule several drums with them, I can't imagine that I would want to haul a trailer from here to Portland on a trip to see the kid though.

 

the specific gravity of av gas is lower as stated we used to added 20% methanol then add acetone to bring up the weight until the specific gravity, that was within the legal limit.but that was before we could get race gas.

 

The last years that Calif. had leaded 92 at the Union 76 station, we had a family reunion in Corona. I had a Dodge Ramcharger 440 and an 800 CFM Thermoquad with the 30 gal tank. I had 10 gallons of the 92 and drove to the local airport and got some 100/130; $20 @ $1.85/gal. = 10.8 gallons. So we're lookin about 50/50. I left San Fernando for Corona. That damned truck was purring like a kitten before I hit Chino. I drove to Corona, took some cousins to the beach in OC, back to Corona, back to the San Fernando Valley and still had an 1/8th of a tank. I never did check the mileage with that mix, but I'm telling ya, it ran very quiet & the gas gauge stopped moving. The rings seated and the exhaust smelled immensely better. I always used 92 but after a few months it was back to running rough. Gas just aint what it was in the old days.

As for purchasing fuel on an airport for your car. It's not illegal and no one cared back then, the fueler would let you put your plane number on the ticket OR pay the road tax (I'm not telling which method I used, but I guess there's your answer lol). Today things are tighter in a post 9/11 world. Airport Management has to answer to a higher authority than the County. TSA pokes their heads into everything! It is illegal to put lead into a non lead post '75 car. My truck was a 1974, the year before cat's. They still use some lead in Av Fuel because as the attendant at my airpark says "They don't like airplanes falling from the sky".

Another thing about octane. They use a formula and it's not true octane anymore. You can see the formula at the bottom of the yellow pump sticker. It's like stereo 'watts'. A 30 watt booster used to blow you out of the car with your ears bleeding. Now its says something like 300 watts "RMS". Yeah whatever...

In 1980 I was coming back from Tusla through Seligman AZ and the man was there from Chevron testing the octane on the west end of town. The pump said 92 octane. His test gidget said it was 105. I didn't mind at all, neither did my '65 389 GTO. He said the 92 was a minimum. Now, it all just sucks. Cali is 91 tops and Utah thinks that 90.5 is "Premium" Go Figure. But obviously high octane doesn't damage engines. Grandpa said in the 50's "Ethel" used to be 100+.

In all of this remember that Octane is 'resistance to ping'. Flash point & burn temps are another thing. Those hydrogen generators the guys are putting on cars up the octane to 115+ and actually help cool the combustion temps, making the older cars pass smog. Cooler combustion chamber temps keep NOx down. I've heard alcohol has a high octane too, but I don't know where it burns... My point is that a little av fuel wont hurt, but you want to check out fuels that have a low burn temp as well as hi 'resistance to ping' for that hi compression ratio.

I believe the higher the octane, the cooler the burn temp anyway. When Chrystler came out with the Lean Burn system in 1977, it was to fire the plug twice because the flame front kept going out in the cylinder!. They had to reignite the fuel to finish the stroke! They had a problem with NOx too. The low compression and crappy gasoline ran the combustion temps off the chart.

The problem is most airports, even the small ones are fenced anymore. Try getting past the gate. You could go talk to the office and see if the fueler is aloud to fuel you, then he can let you in. Another thing is having a large filler hole. My Ramcharger had no problem. I've heard of some filler nozzles being to large for a standard car. Pilots that use av gas put it in 5 gallon army cans first to take it home. I like the towing a small trailer idea. I'm usually towing a trailer anyway. Being a trucker, I feel funny going down the road and not having a little tail swing going on lol!

my long winded rant is over, thank you for listening, sorry I didn't have popcorn

 

when i was circle trak racing we tried running it in my race engine on the dyno it had a hugh performance loss. spoke to the fuel company who had one of there engineers contact us they stated that the fuel had a higher level of voc's for hotter combustion but the fuel was not designed for high rpm performace and would fall short over 3500 rpms. Which is what the dyno showed on a 7500 rpm run.

 

Actually methanol burns cooler than gasoline. I don't know if there is a legal issue to running it on the street, but I doubt that anyone would notice if you were just spraying a gasoline engine. It is not the octane boost that you would get from spraying one so much as it is the fact that it would cool your combustion chamber. If you were running a pure alchy mill on methanol it would probably be an entirely different story. They are really hard on the lungs, the wife can't even go to the staging lanes when they are running alchy burners any more, he asthma has gotten too bad.

Once when I was flat tracking one of Hap's bikes we put an alchy carb on and ran it on methanol. It was a hoot until they kicked us off the track.

I think that now days what you are buying for gasoline has a cetane rating as opposed to an octane rating. I don't know what the difference is.

There used to be a Sunnoco Station just past Big Cabin on the way to Muscogee (sp?) and they still sold all the different grades just like in the '60s. That was in the '80s and I have no idea how they were in business back then. I loaded up an old Blazer I had with 110. It got a lot better fuel mileage with the hot stuff. Never the less the station was an oddity, you surely couldn't cruse cross country depending on it.