AV100LL Gas

I put 5 gallons of AV100LL gas in the 410SA today and it ran beautifully. There was approx 3 gallons of 91 unleaded in there already, so I guess the car likes the fuel combo. I had none of the idle engine shut down issues that plagued the car on 91 and the car came up to temperature quite quickly allowing the choke to be put all the way back in after less than 2 miles.


BTW, I had forgotten how much torque those old Lampredi engines have. The car pulls strongly all the way through the rev range and it is sneaky quick for such a grand old car.

 

Your car doesn't like reformulated gasoline. The problem with avgas is if you use too much, it has less density/specific gravity. This means it will burn lean if you are tuned for street gasoline. Irrespective of octane, if you use 100% avgas and are tuned for street gasoline, you can fry your engine. Running up to 40% should'nt be a problem though. The real question is, why are you guys with these special cars, not buying racing gasoline for your fair-weather cars? Racing gasoline at least has the proper distillation curve.

 

410SA,

Glad to see the AVgas blend worked!


JCR,

I've been running a 50/50 blend for years. My engine likes it and it's fun to fill up on the tarmac.


Regards,

Art S.

 

you guys are freaking nuts. AV gas IS NOT MADE FOR CAR ENGINES.

given the very high cost of rebuilds, i would not be too casual running that stuff in your freaking vintage ferraris.

i am an aircraft mech, and i have seen too many recip engines blown up by av gas for " fun " in lesser vehicles.

AV gas is also NOT COMPATIBLE with the seals and fuel lines or the carbs in a regular gasoline vehicle.


by a case in volume of octane booster.....

thecarreaper

 

Michael,

AVgas may not work well on 3X8s but the older motors respond well to it.

100LL may be a slightly different volatility but, it is relatively similar to fuels available for cars in the '50s and '60s. The differences are addressed by running a blend with standard road fuel. Besides, the lead is good for many of the parts of these old cars.


Regards,

Art S.

 

I totally agree. Many older motors that ran with the leaded fuels need something like AVgas to run properly especially when the valves used the lead to seat properly. If you run just unleaded it could burn a valve stem

I ran Av gas in my 69 Vette and it ran better than using an additive with pump gas but ultimately it runs the best on Cam2 110 octane or better.

The other option is having hardened valves installed and backing off on the timing to control ping.

 

Why? What material are the fuel lines and seals made of in aircraft? Do vintage aircraft use AV fuel? I wanna know really I do.

 

AV100LL has no seal compatability issues with automobiles. Art S has the right approach by cutting the avgas with street gasoline. This helps negate some of the problems with avgas in automobile engines. For avgas these are: the distallation curve for avgas is for low RPM constant speed engines, low RVP compared to street gasoline, and also avgas's lower specific gravity (it's less dense than street gasoline)

 

410 SA: I just add the real deal, tetra ethel lead, not those other additives in the auto shops, to my street gas, I buy the TEL from a factory in Indiana, add the proper amount with each fill, it costs little and my two Ferrari 12s love it

 

Michael,

The advantage of AVgas is there are no additives. A blend will have reduced additives. Adding lead has benefits but all of the junk is still in the fuel.

Regards,

Art S.

 

consult your aircraft maintenance manual. recip engines have seals and gaskets with different material specs as dictated by the manufacturer to be used specifcally with the av gas they will be in contact with. av100ll, jet a, all have different specs . hell even the lock-tite and rvt liquid gasket specs differ from serial number range to serial number range and from maker to maker.

sorry i opened my mouth, i would hate to see a lovely vintage v12 ferrari engine with damaged valves and pistons. as far as 308s go, they are way too low in compression ratio to care about av fuel mixes. i only run 93 as its cleaner and more stable in the fuel system.


next time we blow up a go cart engine with av gas i will take pics.

 

Art: I do agree that there is too much junk in auto fuel (thank you EPA) but here in DC its a bit tough to get a car inside the wire of an airport, let alone close to one of their fuel dispensers! M

 

Please do not look at my reply as an attack. I seek to understand and know the facts. I too occasionally use AV gas in several of my cars, and in my motorcycles when I had them. I liked the noticable improvement in performance, but recently had a problem with a fuel level sending unit (the float melted) and suspect that it was the AV gas. I tried it in my Alfa, but I felt it was running lean. It did run smoother though.
I tend to believe that AV gas is made for planes and should not be used in cars, but I couldn't resist trying it. I certainly would not put gear oil in my car's crankcase. And ATF will destroy some engine seals, so I see your point about different materials and potential incompatibility.
Does anyone have specific info on AV fuel composition vs. Gasoline? Its not that hot of a topic for me, but I see knowing what damage it can do, I can spot it when I see it for my customers' sake. And I will have facts to present to argue its use/disuse.

Thanks.
Erik

 

This book has a chapter on aviation fuels.

http://www.amazon.com/exec/obidos/ASIN/0760300542

 

Thanks.