54 C / Use of Aviation Gas

[Ora Ashley]

Fuel experts,

I acquired my 54 Commander Coupe in 1998, which had been in storage since 1977. I began restoration soon after. I found the fuel tank in pristine condition, due to it having a half tank of aviation fuel. The orginal owner had a small airport and several planes. My understanding is he never burned anything else. I further understood, he would need a head job every few years. Once I prepared the engine for starting, I used the existing fuel in the tank and it ran fine. I left the aviation fuel in the tank and lines and continued on restoring everything else. I was amazed that the fuel was still good after all those years!

I am now close to project completion and have been starting the car, again with the same half tank of aviation fuel. The question I have is, anyone have an opinion on this good or bad? I know the aviation fuel is assessible and is leaded, but it also is higher octane. The benifits as I know them is good performance, leaded and has a built in stabilizer.

Thoughts or comments?

Oran



Oran Ashley

http://photobucket.com/54stude

[maxpower1954]

I use 100 octane Avgas in my R-1 Avanti and R-2 GT Hawk all the time and have for years. The only downside is the price, about 3.60 a gallon now. And I have FAA approval to run auto fuel in my Cessna but the ten percent alcohol in it is causing vapor lock and fuel seal problems, so we are dropping that idea for now.

Another plus to using 100 oct is the much higher vapor boiling point.
I took the GT to the Mountains with a load of 100 octane, everything was great until the tank was down and I refilled with 93 oct 10 % alcohol...never quit, but hill climbing became exciting, BTW before the 10% alcohol switch I had never experienced vapor lock in a Studebacker.

I'm not sure what you meant by rebuilding the head every few years. It wouldn't have been caused by running 100 octane. It does no harm whatsoever to run high-octane fuel in a low-compression engine, some people seem to think it will burn up something, which is wrong. The harm comes when you run lower-octane in a high compression engine because of detonation. The small amount of lead in Avgas is to boost the octane, not lube the valves. Avgas has mil-spec stabilzers, that I thought were good to 10 years but I'm not suprised your 30 something year old gas is fine. Use Avgas with confidence,the cars will run great on it and never worry about old bad gas again, and try to make arrangements to find more (HINT small, out of the way airports would be most open to the idea of selling to you for car use.)Here's a link to an airport in your area that seems to fit the bill. Show up in your Studebaker, that always helps!

http://www.airnav.com/airport/10C

Like that color blue on your 55, Oran! Russ Farris

[Warren Webb]

The difference is REALLY noticable!! I got 5 gallons of 100LL av gas some years ago & put it in my 72 Honda CB500 motorcycle. When I nailed the throttle going up 190th st from Pacific Coast Highway in Redondo, the engine was so much stronger the clutch started slipping from all the power! That never happened with pump gas. Nowadays av gas is a bargin compared to racing gas sold, only station I know of around here wants $8.00 per gallon for racing gas!

60 Lark convertible
61 Champ
62 Daytona convertible
63 G.T. R-2,4 speed
63 Avanti (2)
66 Daytona Sport Sedan

[Swifster]

100 octane is available at the pump (unleaded). I don't believe it has ethanol. AV gas and auto gas has a completely different blend of detergents for the specific use. I've heard over the long haul AV gas isn't that good for the car, but I'll admit without talking to someone who produces the stuff I'd consider it heresay.

I've used 100 unleaded in my Suzuki race car in the mid-'90's and the car ran a lot stronger than Sunoco 94 octane. It cut 1.5 seconds off my lap times on a 1.5 mile road course.

---------------------------------------------------------------------------------------------------
Tom - Mulberry, FL

1964 Studebaker Daytona - 289 4V, 4-Speed (Cost To Date: $2125.60)

1964 Studebaker Commander 170-1V, 3-speed w/OD (Cost to Date: $623.67)

[Laemmle]

$3.60/gallon?.........man that is cheap! Just filled the Avanti with Sunoco 110 leaded........set me back 200 big ones:-(

quote:Originally posted by maxpower1954

I use 100 octane Avgas in my R-1 Avanti and R-2 GT Hawk all the time and have for years. The only downside is the price, about 3.60 a gallon now. And I have FAA approval to run auto fuel in my Cessna but the ten percent alcohol in it is causing vapor lock and fuel seal problems, so we are dropping that idea for now.

Another plus to using 100 oct is the much higher vapor boiling point.
I took the GT to the Mountains with a load of 100 octane, everything was great until the tank was down and I refilled with 93 oct 10 % alcohol...never quit, but hill climbing became exciting, BTW before the 10% alcohol switch I had never experienced vapor lock in a Studebacker.

I'm not sure what you meant by rebuilding the head every few years. It wouldn't have been caused by running 100 octane. It does no harm whatsoever to run high-octane fuel in a low-compression engine, some people seem to think it will burn up something, which is wrong. The harm comes when you run lower-octane in a high compression engine because of detonation. The small amount of lead in Avgas is to boost the octane, not lube the valves. Avgas has mil-spec stabilzers, that I thought were good to 10 years but I'm not suprised your 30 something year old gas is fine. Use Avgas with confidence,the cars will run great on it and never worry about old bad gas again, and try to make arrangements to find more (HINT small, out of the way airports would be most open to the idea of selling to you for car use.)Here's a link to an airport in your area that seems to fit the bill. Show up in your Studebaker, that always helps!

http://www.airnav.com/airport/10C

Like that color blue on your 55, Oran! Russ Farris

[maxpower1954]

quote:Originally posted by Swifster

100 octane is available at the pump (unleaded). I don't believe it has ethanol. AV gas and auto gas has a completely different blend of detergents for the specific use. I've heard over the long haul AV gas isn't that good for the car, but I'll admit without talking to someone who produces the stuff I'd consider it heresay.

I've used 100 unleaded in my Suzuki race car in the mid-'90's and the car ran a lot stronger than Sunoco 94 octane. It cut 1.5 seconds off my lap times on a 1.5 mile road course.

Yeh, I'd say it just that Tom - heresay. I've been running avgas off and on for 20 years, with the only problem being the damage to my wallet.

Works the other way, too...back when I learned to fly, the common wisdom was if one were FOOLISH enough and had a death wish, running auto fuel in an aircraft engine would destroy it in a orgy of detonantion.

Well, in 1978 the Experimental Aircraft Association ran a test with a Cessna 150, which has a low-compression engine, hundreds of flight hours and had ZERO problems. The door was cracked open, and now virtually all light aircraft with gravity feed fuel systems and low-compression engines can be certified to run on regular grade auto-gas, with no modifications. Even some DC-3s with P & W engines are auto-gas approved. My 1952 Cessna 170B has a Continental O-300 engine with a 7.0 to 1.0 compression ratio; I've had lawn mowers with more than that! It has run happily for years on auto fuel. But 30 years later, there is still a fairly large group out there who think it's dangerous, bad for the engine, ect. without one shred of evidence ANY of that is true. Whoever told you avgas wasn't good for your car (we are talking old cars here) probably belongs in that elite group who like to invent imaginary problems. And I take what a manufacturer has to say about anything with a grain of salt, because they are scared to death of liability. Lycoming and Continental have always maintained auto-fuel was not recommended for use, just CYA for them. The FAA thinks otherwise, and the record proves it.

So...I run avgas in the Studebakers, and autogas in the Cessna...I must be saving money, somewhere! Russ Farris

---------------------------------------------------------------------------------------------------
Tom - Mulberry, FL

1964 Studebaker Daytona - 289 4V, 4-Speed (Cost To Date: $2125.60)

1964 Studebaker Commander 170-1V, 3-speed w/OD (Cost to Date: $623.67)

[Ora Ashley]

Russ,

Makes sense, sounds like no real harm using the AV gas at this point, other than I may need to drain the 30 year old stuff and replace with some fresh. In terms of access, I live very close to small airport and will be able to pick up more AV gas. In terms of fuel economy or cost, I do not intend to use my project car as a driver. In regards to vapor lock, I heard these older studes were prone to vapor lock. To address that problem, it is interesting the only modification the original owner made to my 54 C Commander, was to install an inline electric six volt fuel pump. My understanding was that the six volt pump was taken from an old helicopter. I currently have it disconnected, due to my engine restore and detail. I know, five years ago when I used to start the engine, the electric fuel pump would kick on. I plan to hook it back up.

Again thanks for the insights!

Oran

quote:Originally posted by maxpower1954

I use 100 octane Avgas in my R-1 Avanti and R-2 GT Hawk all the time and have for years. The only downside is the price, about 3.60 a gallon now. And I have FAA approval to run auto fuel in my Cessna but the ten percent alcohol in it is causing vapor lock and fuel seal problems, so we are dropping that idea for now.

Another plus to using 100 oct is the much higher vapor boiling point.
I took the GT to the Mountains with a load of 100 octane, everything was great until the tank was down and I refilled with 93 oct 10 % alcohol...never quit, but hill climbing became exciting, BTW before the 10% alcohol switch I had never experienced vapor lock in a Studebacker.

I'm not sure what you meant by rebuilding the head every few years. It wouldn't have been caused by running 100 octane. It does no harm whatsoever to run high-octane fuel in a low-compression engine, some people seem to think it will burn up something, which is wrong. The harm comes when you run lower-octane in a high compression engine because of detonation. The small amount of lead in Avgas is to boost the octane, not lube the valves. Avgas has mil-spec stabilzers, that I thought were good to 10 years but I'm not suprised your 30 something year old gas is fine. Use Avgas with confidence,the cars will run great on it and never worry about old bad gas again, and try to make arrangements to find more (HINT small, out of the way airports would be most open to the idea of selling to you for car use.)Here's a link to an airport in your area that seems to fit the bill. Show up in your Studebaker, that always helps!

http://www.airnav.com/airport/10C

Like that color blue on your 55, Oran! Russ Farris

Oran Ashley

http://photobucket.com/54stude

[Bud]

I use avgas in my Studes when I can get it. In tha Los Angeles area, 100LL is going for around 4.20 per gallon. I usually put 5 or 6 gallons in with pump gas which stops the detonation and hot hard starting problems in my Avanti and 62 Hawk with flat top pistons. Bud

[avantilover]

So, if I put 98 octane fuel in my 1962 lark regal 259 engine that is OK? Had thought it may help to clean the fuel system in a tank full or two.

John Clements
Avantilover, your South Australian Studebaker lover!!!
Lockleys South Australia

[53hardtop]

While higher octane (premium) fuels may help clean out your fuel system, it is not the octane that does the cleaning, it is because premium fuels typically contain detergents.

Adding higher octane fuel to a low compression engine will not result in a noticable gain in power. I get a kick out of the guys who buy octane boost to put in their stock engined car in the hopes that it will increase the performance. It won't. If you have high compression, then you need octane. Remember, higher octane means slower burning.

I like to think of it this way: For a given engine, you will get the best performance running the lowest octane fuel you can run that does not cause pre-ignition. If you get pre-ignition running a low octane fuel in a performane engine (i.e. high compression) then increasing the octane to a point that eliminates the pre-ignition will increase the performance. Additional octane level beyond what prevents pre-ignition will have little or no effect on performance.

Rob in ND

[41 Frank]

Now here we have a poster who knows of what he speaks. All you say is true,except I don't agree that premium has any more detergent than any other grade in a given brand. People who fill their tank once in a while with premium, thinking they are treating their engine to something special are only relieving their bank account of more money than necessary.

quote:Originally posted by 53hardtop

While higher octane (premium) fuels may help clean out your fuel system, it is not the octane that does the cleaning, it is because premium fuels typically contain detergents.

Adding higher octane fuel to a low compression engine will not result in a noticable gain in power. I get a kick out of the guys who buy octane boost to put in their stock engined car in the hopes that it will increase the performance. It won't. If you have high compression, then you need octane. Remember, higher octane means slower burning.

I like to think of it this way: For a given engine, you will get the best performance running the lowest octane fuel you can run that does not cause pre-ignition. If you get pre-ignition running a low octane fuel in a performane engine (i.e. high compression) then increasing the octane to a point that eliminates the pre-ignition will increase the performance. Additional octane level beyond what prevents pre-ignition will have little or no effect on performance.

Rob in ND

[Bud]

If your engine doesn't detonate on regular grade gasoline, I would recommend using it. Stock Studebaker engines don't have a compression rstio higher than 8.5 to 1 so regular gas should work fine if the engine doesn't have cooling system blockage or ignition problems such as over advanced spark or a worn out distributor. Just buy your gas from a reputable supplier and your car won't know the difference between regular and premium gasoline. Avgas has a longer shelf life than pump gas, but its use or the use of an octane booster is a waste of money for most Stude engines. Bud

[avantilover]

Thanks guys, I use 91 Octane and thought I'd try BP Ultimate Premium, but at 14 cents a litre extra it's obviously not worth it, although Jim Pepper states on page 20 of the June 2009 TW ""....the octane requirement slightly higher on a 259 than a comparable 289."

John Clements
Avantilover, your South Australian Studebaker lover!!!
Lockleys South Australia