Av gas

[Mark Husar]

I am considering using av gas 110 for the cobra this summer, instead of the regular racing gas I purchase.
Any pro's or con's from drivers who have done the same?
Thanks

[RACER X #99]

http://cx500.gobinet.se/wwwboard/tur...ages/2301.html

[Mr.Fixit]

stick with race gas until you do most of your driving at 35,000 ft elevation

[Jim Downard]

As a private pilot, I can tell you that this is not such a great idea. I had friends who wanted to use it in their motorcycles as they simply saw the number 110 octane and assumed that is would equally corrospond to auto gas. It does not. They are not rated the same. In addition, a 180 hp Lycoming opposing 4 cylinder engine makes that hp at full throttle. Max rpm is 2700, and the plane us usually flown at at least 5000 ft. Aviation engines also have a manual means of continuously adjusting your mixture and using your exhaust gas temp gauge to control the mixture setting. My advise. Use gasoline refined for use in automobiles, not engines that turn low rpm at high altitude. By the way, most naturally aspirated airplanes lose hp and can't attain an altitude much over 14000 ft.

Jim Downard

[DAVID GAGNARD]

All good advise so far.....

About 10 years ago when I was with some buddies on a dirt track car we had a local Shell station sponsor our fuel... He would give us 10 gallons of fuel per night of racing,any kind he had.... Well, he had AV gas and we used it for about half a season,car ran good,no real problems,halfway thru the season we switched engines (we had 2 identical engines) and "freshened" up the first one,when we tore it down there was a nice black carbon looking coating thru out the engine... BTW,we changed the oil and filter after every other race....

Talked to a Shell enginner later and told him what we found,he said AV gas was probably the worst thing to put in an automotive engine for fuel.... He said the AV gas has a number of additives for high altitude-air cooled engines-to prevent condensation and a few other things I can not remember....We began running racing gas again bought at the track and after a half season when we tore down an engine it looked almost as clean inside as when we built it....

Racing gas may be more,but it is made for race engines at mean sea level....

David

[Mark Husar]

Thanks guys!!!

I am sure that you saved me one heck of a lot of work later on.
I really appreciate the response.

Mark

[Rwillia4]

New Guy Here-

A lot of AV gas also has traces of lead (yes like leaded gas). Usually the pump/truck will even have "LL" after the octane #, this means Low Lead. It tends to leave "stuff" behind as David said...

Willi

[justa6]

I'm an airline pilot with a fair amount of General Aviation flying.

Av Gas is a bad idea for all of the reasons already mentioned. However, there are other ways around the "octane" problem. None of them involve off the shelf products like "Octane boosters". These booster talk about raising your octane by several "points". The points they are talking about are "tenths" of ONE octane.

There are some fairly easy alternatives. You can raise 93 octane fuel to 96/98 by adding either Toulene or Xylene. This is what they add at the refinery (along with other things) to raise octane.

I've found that I can get away with 11.5 to 1 compression with a gallon of either Toulene or Xylene mixed with 93 octane. BUT YOU MUST MIX THE STUFF WITH GASOLINE IN A CAN FIRST. DO NOT GET EITHER on your paint full strength. DO NOT GET EITHER ON YOUR HANDS.

These products can be purchased at most paint stores and contain no lead.

Also, someone mentioned that LEAD was somehow bad for you motor. That isn't entirely true. Lead is bad stuff but you engines valves "like it". The car company's had a lot of problems with valves when lead was first removed from street gas. Modern valves can do fine without Lead. But it certainly won't hurt your motor UNLESS you have a Catalytic converter. Don't use leaded gas with a CAT or an O2 sensor. It will destroy both.

I bought a 50 gallon drum of 117 octane race gas and put a couple of gallons in my cars tank when I fill it with 93. Works great and SMELLS terrific. And yes it has lead in it.

[DAVID GAGNARD]

Bob;

I also use toulene in my gas to raise the octane for racing purposes,for street driving I just use 93 octane with no problems...

What mix ratio do you use???? You say you use one gallon of toulene,but to how many gallons of 93 octane gas to get 96 octane????

Went to Wal Mart and Auto Zone last week to get a gallon of laquer thinner (toulene) for that purpose,they went up in price from 4 bucks a gallon to 8 bucks a gallon in the last couple of months since I last bought some.... Talked to a local body shop that I do business with and he told me he buys it in 5 gallon cans for cleaning the paint guns,he uses a generic inexpensive brand and he did not remember the price but thought it to be around 3 bucks a gallon and will get me five gallons at his cost.....Sometimes it pays to have low friends in high places I guess....

David

[ToyCollector]

The other thing to note for any of you who would ever entertain this idea, like I have, is that no AVGAS is completely without lead. If you run it in a car with an O2 sensor, it may not take more than a tankful to ruin it. Don't ask me how I know .