Aviation gas in Model A

[Ca. Kid]

Yesterday when I was at the county airport a club member called me and said he was out of gas in his Model A near the airport. I explained to him we didn't have auto gas, only avgas 100LL, which is 100 octane with no alcohol and a small percentage of lead. I have burned 100LL in everything from an antique Curtis 0X-5 to chainsaws with no problem. He agreed that it should be ok as he only had 5 miles to get home. We put in 2 gallons and off he went.
Later that evening he called and told me what happened. After about 3 miles the engine stared heating up and missing, by the time he got home it was running on 2 cylinders with a blown head gasket. He was pulling the head last night so I hope that was the only damage.
My question is do any of you petro chemical engineers have any ideas as to why 100LL would cause this or was it just a coincidence?

[Jason in TX]

Well, with that high of octane, he should be able to run extreme advance. As far as the heat, he may have been running the engine too retarded.

Also, the lead can foul the plugs. He may just want to pull the plugs and see if they are really dirty.

I would think you could run a model A on moonshine though without harming it.

[CarlG]

Model As ran on leaded gas for years before the advent of "unleaded"

When I worked for an aricraft repair facility, we used avgas (100LL) in all our off road equipment -- forklifts, tugs, weed eaters, lawnmowers, etc. This was usually gas we had drained out of aircraft tanks and could no longer be used. It was easier to use it that way than find a way to dispose of it.

[Purdy Swoft]

I ran 100 octane leaded gas as long as I could get it in all of my cars, lawn mower and chain saw with no problems. I wish I still had a soarce. Leaded fuel will cause carbon deposits but thatr was never really a problem for me. I would MUCH!!! MUCH!!! rather have 100 octane leaded gas than unleaded ethanol adultrated gas any day. If something isn't done about the ethanol adultrated fuel,It will be the death of the old car hobby.

[Pete]

I would say your friend's problem was not related to the av gas.

[real550A]

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Purdy, I agree....years ago, we had "Clark Super 100" stations all over Minnesota. All they sold was 100 octane leaded gasoline. I could tell the difference right away when I put it in a Cushman Eagle, or mini-bike. It also made the old 4 cyl. Porsche bathtubs go fast! Looking forward to the end of the ethanol nonsense.

[Purdy Swoft]

I wish I had kept the Cushman eagle . I agree, The leaded 100 octane gas made a huge difference in power and reduction of timing knock.

[H. L. Chauvin]

If one visits coastal areas, one finds complaints that ethanol gas dissolves marine rubber gas lines & certain synthetic marine gas tanks -- many 4 cycle engine boat owners have already switched to aviation gas with absolutely no problems.

[Louis]

Back in the late 70's when we defuel'd acft. for maint. a lot of the purple 115/145 ended in the gas tank of my old chevy. along with some of the other maint. guys vech. no one had any problems from using it, I coulden't tell any real diff. in it except for the price of course .
I don't think high oct. has to do with power as much it does with anti. knock in hi comp. eng's run at hi power, The 4360's of the day would pull 62.5 in of manifold press at max power. I never ran my old chevy. that hard to really tell the diff. in power then the reg. auto. gas.
I doubt if the avgas had anything to do with "A" model eng's problem's.
Sounds like an operator problem to me .....JMHO.

[John Butts in CT]

At the risk of igniting a firestorm of criticism, here goes:

Leaded gas was NOT universally available '28-'31.

STOCK "A's" didn't need it then, nor do they need it now.

With that off my chest, here's my personal fuel formula from a very old post (and you can now add another year to the dates in the post, and all's still well with E-10.... still good.)... (as for octane.... mix and match until your car's happy... c'mon guys/gals... it's only a few cents difference per tank):

Here's a repeat of a post of mine from an old "Do A's tolerate Ethanol..." thread. I still swear by it. MMO and Star Tron are two of my six steps to coping with ethanol:

"In prior threads here and on the old Barn I shared my experiences with creeping neoprene goo after E-5 appeared in New England. I'm not going to cover old ground; we've all heard about how the fuel separates, evaporates, turns to corn syrup, dissolves neoprene, etc., etc.

Cutting to the chase, the following formula has given me four (SIX as of 2011!)consecutive years of driving without a single fuel-related problem... E-5, E-10, 87, 89, 91 Octane, whatever:

1) HARD Neoprene gauge float, NOT CORK.
2) CORK gauge gaskets, NOT NEOPRENE.
3) MMO added to gas, per manufacturer's instructions.
4) Star Brite "Star Tron" (the blue stuff) added to gas, also per
manufacturer's instructions.
5) Run carb dry at the end of each day.
6) The on-board computer (driver) needs to adjust the spark and
GAV "to taste." (The car's taste, that is.)

There, I said it; take it or leave it, it works for me.

Whether it's a day, a week, or a month between starts, the "A" starts first time, every time. (As do my lawn mowers and snow blower, on the same fuel diet, no matter how long the fuel sits.)"

[MrTube]

I find it interesting so many complain about modern day gasoline. I don't know about when the "A" came out, but the mid 1920s WhirlWind airplane engine I mentioned in another thread called for 50 octane fuel. I'm willing to bet the same was available in the model A years.

Yea, we have crap fuel these days, whatever you say.

[700rpm]

"3) MMO added to gas, per manufacturer's instructions.
4) Star Brite "Star Tron" (the blue stuff) added to gas, also per
manufacturer's instructions."

Do you find these better, worse, or no different from adding Sta-bil to the tank when putting the car away for a few months?

[John Butts in CT]

Originally Posted by 700rpm

"3) MMO added to gas, per manufacturer's instructions.
4) Star Brite "Star Tron" (the blue stuff) added to gas, also per
manufacturer's instructions."

Do you find these better, worse, or no different from adding Sta-bil to the tank when putting the car away for a few months?

Hey, Ray:

Call me "old fashioned," but I add them BOTH.

No worries.

JWB

[John Butts in CT]

IMHO, custom-mixed fuel for a Model "A" is like home cooking... better than the "fast food" stuff.

My formula may not be the BEST for everyone, but it works for me. Give it a try.

All the best.

JWB

[Patrick L.]

The only gasoline available at airports in this area is 100LL [ well, a few carry mo-gas]..It hasn't hurt any of the airport equipment we've been running it in over the years.. I use it in a lot of my stuff that sits around a lot as it doesn't break down and varnish..
I believe it should not hurt a Model A at all..
Back in the day when Continentals called for 80 octane no lead and it became unavailable the only thing left was 100 octane low lead.. All the local 'experts' said it would ruin the Continentals and cause guide problems,, I didn't by it.. Now, 15 years later, I can't think of a single problem it caused..

[Bruce Adams]

Originally Posted by 700rpm

"3) MMO added to gas, per manufacturer's instructions.
4) Star Brite "Star Tron" (the blue stuff) added to gas, also per
manufacturer's instructions."

Do you find these better, worse, or no different from adding Sta-bil to the tank when putting the car away for a few months?

Sta Bil now makes a "Marine Formula" for the E-10 which is equivalant to Star Brite's "Star-Tron" which came out a couple of years before Sta-Bil's product.

MMO is totally different and is an upper cylinder lube. I use MMO faithfully in the Model A, and my seasonal engines get either the Star Brite of Sta Bil product in ADDITION to running them dry at end of season. This has helped in all cases save for deteriorated vinyl fuel connections.

[V4F]

without reading all the replies , back when i was racing dirt cars we tried it . the problem we found was 1) to much lead 2) altitude additives & so on . turned out not to be our answer ...............

[MALAK]

Originally Posted by Ca. Kid

Yesterday when I was at the county airport a club member called me and said he was out of gas in his Model A near the airport. I explained to him we didn't have auto gas, only avgas 100LL, which is 100 octane with no alcohol and a small percentage of lead. I have burned 100LL in everything from an antique Curtis 0X-5 to chainsaws with no problem. He agreed that it should be ok as he only had 5 miles to get home. We put in 2 gallons and off he went.
Later that evening he called and told me what happened. After about 3 miles the engine stared heating up and missing, by the time he got home it was running on 2 cylinders with a blown head gasket. He was pulling the head last night so I hope that was the only damage.
My question is do any of you petro chemical engineers have any ideas as to why 100LL would cause this or was it just a coincidence?

It is a common misconception that high octane gasoline burns hotter and will provide a performance increase over lower octane fuels. This is bunk. Sure if any given engine is running too low an octane and as a result has preignition/detonation then running a higher octane will provide a performance increase by minimizing/eliminating those conditions. However the additives required to raise the octane rating also lower the BTU/unit. http://www.appropedia.org/Energy_content_of_fuels
The BTU difference between Avgas and 87 Octane is only 3.8%.

Jason in TX Re: Aviation gas in Model A
Well, with that high of octane, he should be able to run extreme advance. As far as the heat, he may have been running the engine to retarded.

Also, the lead can foul the plugs. He may just want to pull the plugs and see if they are really dirty.

I would think you could run a model A on moonshine though without harming it.

So I'm with Jason on this one. He may have been running it a little on the retarded side but unless he drove it up a 10% grade for 20 miles I doubt it made any significant difference. Sounds more coincidental to me.

[Aerocraft]

I would agree with those that believe the problem is not related to av-gas. I burn 100LL in the Model A engines in our Pietenpol Aircamper. Years ago, I used 80 octane av-gas until it was no longer available and then switched to 100LL for our first Pietenpol. I would much rather use av-gas than ethanol laced auto gas. Gar Williams

[Paul from Maine]

About 20 years ago, I drained about ten or fifteen gallons of 100LL out of a Cessna 182 straight into the '73 Galaxie I was driving at the time. No performance difference. Been runnin' 100LL in my low compression O-200 Continental for over twenty years. Besides fouling the plugs once in a while, no performance difference from the old 80 octane or car gas we used to use (had an STC for AutoGas). Can't believe that 100LL ruined an A engine. The O-360 in the Cherokee loves 100LL. Hasn't blown that up yet, either!

[Ca. Kid]

Thanks for all the input. However I am going to rule out operator error, this guy is very experienced in Model A's as well as T's. I am sure it was just a coincidence. The head gasket was probably going to let go anyhow.

[Clem Clement]

I have 2500 hours carried by 4360's. Love those huge round engines. My rememberer thinks the max MAP was 62.5. Sweet powerful engines. I have 2250 hours in WB-50s and 350 in KB-50s. I remember we cautioned the guys not to put 115/145 in thier scooters. Flying Convairs with R2800s and 100/115 I thought there was no problem.

[Louis]

Clem,
You are right, it was 62.5 in. water and alch, and 63 in. dry full rich.
I was a flight eng. on Shakey's for 9 year's. [corn cobb eng,s].
Max Powe .

9800 hundred hr's....Just a bad mem.

[Clem Clement]

Louis,
Without you FE's mastering them big engines nothing would have happened. You guys were miracle workers. Like playing an organ on take off. I have the greatest respect for your profession.

One time at Eilson, we took of at -56 deg F. Our FE briefed us not to be frightened by the throttle positions. It seemed like 1/2 throttle when we reached max power.

[Louis]

Wow!..-56 deg's , Yes, It was easy to over torque on a cold day.
I liked it better at Wake, at 90 degress in the morn. after a long night at Drifter's Reef with a bad hangover, thinking about Mag drop charlie.

Sorry guy's I just had to thro. that in their. for ole guys like Capt. Clem and me, Please overlook .

[Charlie Stephens]

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Running av gas in a Model A is like running high octane gas in a modern car designed for regular gas, no damage to the car only your pocket book. With ethanol out there I wish I could find a source of av gas for my Model A since it doesn't contain ethanol. I doubt the gas was responsible for your friends engine problems.

Charlie Stephens

[Clem Clement]

Our KB's went thru Wake, But I joined the 421st after those missions were finished. The tanks were haulin the Thuds to west pac(Itazuke). I have forgotten the stories about old Mag check.

I do remember coming to the WB at Goose one chilly morning and gas is running out of everywhere. The ground crew put Herman -Nelson heaters on all the Whitaker sliding gate vales in the flap wells and the gas running stopped. They signed the aircraft off... I was not happy but the WB did not blow up.

Again at Eilson we were told to crank a parked WB that was outside with a foot of snow on it. I was a junior guy so the AC and FE took me with them. The AC told the rest of the crew to stay in the warm hanger. This was one of those dumb things we sometimes were told to do. If you remember the Starter CB's were huge and buried some where in the wing root. About 10 seconds on each starter and pow! The ground crew had hours of work in the icey aircraft to change all 4 of the CB's.

Cold weather ops was surely different. In the good side, we had a mx guy who got a terrible rash in Hawaii. The FS could do nothing with it. The fellow was missing trips and not getting good reports. Finally he begged to go and the sent him with us to Alaska. The cold cleared him up in a week!! And he got promoted the next cycle. Those were the good old days when mx was part of the Squadron.

[John Butts in CT]

Originally Posted by Bruce Adams

Sta Bil now makes a "Marine Formula" for the E-10 which is equivalant to Star Brite's "Star-Tron" which came out a couple of years before Sta-Bil's product.

MMO is totally different and is an upper cylinder lube. I use MMO faithfully in the Model A, and my seasonal engines get either the Star Brite of Sta Bil product in ADDITION to running them dry at end of season. This has helped in all cases save for deteriorated vinyl fuel connections.

Hey, Bruce:

As I said in a private message to another Fordbarner:

"Sta-bil (the pink stuff) is useless with ethanol.

We really need to use the BLUE stuff.

Star Brite's "Star Tron" was the pioneer in this field... and was universally adopted by the marine industry... so that's what I use.

Sta-Bil now has a blue formula.... but I have no desire to switch brands.

I add MMO for other reasons, and my formula works for me."

JWB

[Chris Haynes]

Back in the '60's while I was doing my time for Uncle Sam we had multi fuel trucks. You could put any combustible liquid in the tank and it would run. The most recommend fuel was diesel. but kerosene, gasoline, motor oil, transmission fluid, and even JP4 (jet fuel) were recommended fuels. But in large letters it stated DO NOT USE AVIATION GRADE GASOLINE. There must be a reason for that.

[John Duden]

Originally Posted by Ca. Kid

Yesterday when I was at the county airport a club member called me and said he was out of gas in his Model A near the airport. I explained to him we didn't have auto gas, only avgas 100LL, which is 100 octane with no alcohol and a small percentage of lead. I have burned 100LL in everything from an antique Curtis 0X-5 to chainsaws with no problem. He agreed that it should be ok as he only had 5 miles to get home. We put in 2 gallons and off he went.
Later that evening he called and told me what happened. After about 3 miles the engine stared heating up and missing, by the time he got home it was running on 2 cylinders with a blown head gasket. He was pulling the head last night so I hope that was the only damage.
My question is do any of you petro chemical engineers have any ideas as to why 100LL would cause this or was it just a coincidence?

Have you ever seen "The beverly Hillbillies"? They always used alchole!
John

[Dodge]

How about it ran out of gas, sucked some crap off the bottom of the tank, plugged
a jet in the carb and leaned it out?????
That could explain running hot and blowing a head gasket.
Running a higher octane fuel will richen it up not lean it out.

My 2 cents....

Dodge

[Geo. H]

Guess what the "66" in Phillips 66 originally stood for.

[40 Deluxe]

Maybe the driver for some reason thought he should retard the spark with av gas (oops!). Combine the slow burning high octane fuel with late ignition timing and the exhaust valves will be roasted in no time! Does the exhaust manifold show signs of recently being a bright red color?

[BILL WILLIAMSON]

Neighbors said don't buy Bad Buds gas, it's got ethanol crap in it! That's all I ever run as they had cute girls workin' there. My '30 with a Weber always ran good, never water when draining the cast iron sediment bowl. I always used 7 to 8 gallons a week. Only once it was parked for 4 months when I was in the hospital, started & ran like a champ! Maybe "crap gas" sometimes gets blamed for other malfunctions?????? Most any gas can get crappy with age. Bill W.

[James Rogers]

Originally Posted by Ca. Kid

Thanks for all the input. However I am going to rule out operator error, this guy is very experienced in Model A's as well as T's. I am sure it was just a coincidence. The head gasket was probably going to let go anyhow.

Probably like Dodge said, when it ran out of gas it leaned out and the marginal head gasket got a hot spot and began to fail. With the high octane gas in and running, the head gasket began to burn and allow the engine to overheat. This began a progressive problem that blew the head gasket. Not the problem created directly by the AV fuel but by the operator's failure to fill the tank but would have had a failure soon anyway.

[Keith True]

The small airports here won't sell av gas anymore unless it is being pumped into a plane.Somebody finally caught on,and jumped on them for selling untaxed fuel for vehicles.There is no road tax on aircraft fuel.There were a couple of places selling booze free gas in the lakes region,but they also got caught pumping the gas in cars.I'm not even sure if they are still selling it at all this year.

[visionary]

Aviation gas is an oxygenated fuel and can be used, but the tuneup will have to be adjusted acordingly. (fuel mixture fatened up a little) the av fuel is oxygenated to cope with high altitude.
My 2002 motorhome user manual states in bold letters not to use high octane fuel as it will ruin the motor. i guess high octane fuel in a low compression motor is to hard to ignight.

[40 Deluxe]

Interesting! Do you know what is used to oxygenate avgas? Ethanol? MTBE? Or something else? And how would this affect vapor pressure of the fuel? Avgas has to be formulated to resist vaporizing at high altitudes so it won't "vapor lock". Thus the need for the pilot to know how and when to apply "carb heat". Some years ago a friend from Minnesota landed in Albuquerque, NM in January for fuel and automatically applied full carb heat for take-off as he did in MN. He could only climb to barely above rooftop level until he remembered to shut off the carb heat! Ever notice how hard an aircraft piston engine is to start on a cold day at or near sea level? The fuel doesn't want to vaporize and burn!
On the motorhome I imagiine one danger is washing down the cylinder walls from that unburned "high test" gas which then dilutes the oil.

[40 Deluxe]

In my last post I forgot to mention that my friend also had set the mixture full rich, forgetting he was taking off from a 5,000 ft.+ airport. Leaning also brought the power back.

[40 Deluxe]

Curiosity led me to research the comment about avgas being oxygenated. Info I found says it is not. Such additives are specifically forbidden! I'll see if I can post the link:

http://royalpacificpetro.com/html/te...as_content.htm

[JEC]

When I lived in Missouri and would take my cattle to the sale barn more often than not the tax people would be there testing the diesel trucks for off road diesel. If it came out red the fine was hugemungous.
Hopefully we won't start getting a rash of testing at our model A meets.
The get around on airplane only buying of 100ll is to pick out an n number on one of the airplanes on the ramp and use it. It isn't illegal to buy fuel in a can if you say it is to be used in an airplane. Since you are planning on breaking the law by using it in your car breaking another one won't be that hard.
The Auto gas STC which allows for the use of auto fuel in some airplanes is pretty much useless anymore since the STC doesn't allow any alcohol in the fuel.
John in Tucson

[Jack '29 Sport Coupe]

I ran a tank of av gas in my first A with no problems with a slight adjust on the
advance lever, as Jason suggested. I only did it the one time---put about 30 miles
on the A.

Jack

[Keith True]

I've been down that road of having the red fuel tested.I carried a copy of the law with me in the last few years I drove the truck.Years ago a lot of us would dump a quart of ATF in each tank when fueling.The law read red fuel shall not be the determining factor of a violation,but probable cause for testing.A lot of the additives were red in color so it was really hard to decide who was breaking the law by running untaxed fuel.I always passed my tests.I used to pick up av gas at a local airport for a farmer with a J3,then I had to start filling out forms for every can I filled.Then they wanted the actual owner of the plane to sign them,they really didn't care but somebody was on them about it.Turns out the lineboy knew the farmers plane had been in a ground crash 3 or 4 years ago,never repaired,and couldn't possibly have been using the gas I was buying.Also,I found out my Harley doesn't run one iota different on av gas as it does on 87 octane pump junk.