aviation gas
 

has anyone used aviation gas in a flathead ,some of my street rod friends use it especially when storing the car over the winter, im told it contains no ethanol.

Re: aviation gas
 

We use it in our small tools in the fire department just for the reason that it doesn’t deteriorate as fast as auto gas. The octane is 100 and others may comment on any effect that might have on timing needs, if any. We’ve also used it in the department's antique 1945 Mack pumper with good results. No, it’s not a front line piece.....;-)

Re: aviation gas
 

Octane rating is way more than a normal street flathead. A high CR OHV engine might benefit. Non-ethoanol fuel should be available most everywhere. Marine usage, farm usage, etc.

Re: aviation gas
 

Use it all the time, very good for vehicles stored any length of time.

Re: aviation gas
 

You can get at your local airport, we have 94 & 100 octane. I use the 94 in all my small equipment, and run it in the Hot Rod around the time to stow if for the winter. No ethanol, superior preservation additives. Think about, a small airplane probably see a lot less use than our cars, so do you want it crapping out from junk gas while you are taking off or in flight. You can also buy the higher octane no ethanol gas in gallon, and 5 gallons cans for small fortune if you have the money, and airport. The current price in my area for 94 AVG is about $7.00 a gallon.

Re: aviation gas
 

I used it for many years in the race car when we ran street class. The good old purple 115/145 was available then.
For street you won't have to tune any different unless you want. It will stand more spark advance so you might gain some mileage there. It has about 4 cc's per gallon of tetraethyl lead so you may have to open the plug gaps slightly to forestall leading.
On air cooled engines such as mowers and trimmer's etc. with 4 cycle engines, you may encounter sticking valves over time, due to the lead. In the old days, they set the stem clearance wider.

100LL is around $5 a gallon here now.

Re: aviation gas
 

A friend who is an airplane mechanic said that if you evaporate a gallon of it in a stainless steel bowl, there is a very faint white residue if anything left over. His side passion is vintage motorcycles, so it matters.

Re: aviation gas
 

I am fortunate to be in a small town 2 miles from the local airport. They let me pull onto the runway and fill up. I prefer running 100LL AvGas in my cars. I have the timing advanced 2 degrees to compensate for the higher octane. AvGas seems to have a MUCH longer life for storage, and is MUCH less prone to vapor lock

Re: aviation gas
 

That would be true, has to work at altitude.

Re: aviation gas
 

Too pricey for me. 93 oct & Sta-bil has worked just fine for winter storage. I run 89 oct during "the season" and have no problems with good performance.

Re: aviation gas
 

airport 1 mile away from me current price for 100LL is 4.75 i will give it a try except for price looks like it has its advantages

Re: aviation gas
 

100LL, has 4 times the amount of TEL in it than standard leaded gas. And i wouldn't run it in anything. In my friends 182 we had an STC for auto fuel and ran 87 pump gas. This was before they started putting alcohol in. We're lucky her in VT as 91 Oct doesn't have Alcohol it it.
Gramps

Re: aviation gas
 

The Suplemental Type Certificate is still valid but a person has to purchase alcohol free auto gas to use it. The web site has the link to the stations around the country that are known to be alcohol free. Obviously, vapor pressure is very important for aircraft use. A person doesn't need vapor lock at altitude. The old engines that used 80/87 work just fine with the STC mogas as long as they follow the directions.

One of the helicpters I maintain has the HIO-360-D1A engine that has 10:1 compression. It was originally designated to use 100/130 green avgas but that stuff is almost non existant now days. The 100LL has a blend with a lower amount of Tetraethyl Lead (1.2 to 2 grams per gallon) but it still has a lot of TEL in there as was mentioned. It is actually blended in at a guaranteed level not to go below the lower amount specified for 100LL but is can have more and does vary in content within the range. My customers have gotten batches that caused lead fowling of the spark plugs so I know it is sometimes more than just minimum in there and may exceed 2 grams per gallon. Mogas never had as much TEL as 100LL for street use. Now days leaded auto gas is generally only used for racing or other off road use since no road taxes are added.

There are fuel police down here in Texas that keep an eye out for farm diesel being used on the street. They mostly just check diesel vehicles on a spot check basis but there is a possibility that they could catch a person using avgas too. It's not legal to use avgas on the street. You can carry it legally on the street in a properly marked tanks or containers but that's about it.

Re: aviation gas
 

You might not know it but the octane method for avgas is different so octane comparison is apples and oranges. However avgas is almost 100% iso-octane with butane added for vapor pressure.

Re: aviation gas
 

When I was involved with the museum and had airport access I would use 100LL in my roadster for winter storage with no issues. I've run and flown in aircraft with 3 or 4 year old avgas in the tanks many times and have some 5 year old avgas/oil mixed for my chain saw. Used it the other day and it started on the 3rd or 4th pull after sitting for 6 months...

Re: aviation gas
 

I would mix 20% with regular gas for long trips in my '42 Staff Car ('G' series Six cylinder) and boy it seemed to run better and sound better too. :)

Re: aviation gas
 

Curious, what is mogas?

Re: aviation gas
 

When you eat beans, you get mogas.......lol

Re: aviation gas
 

Haha. Good one, Pete.

Re: aviation gas
 

'Mogas' is generally recognized as "automotive-grade" gasoline. DD