Why can't we use gasoline in our turbine engines?? It would be cheaper and easier to get.

I think that gasoline increases the EGT too much compared to Jet A1.
You will melt your turbine wheel slowly...

SJ.

I think it's mostly because jet-A has more energy per unit volume.
The gas might work, but it would take a lot more of it to produce the same power level.
Not sure about the temp thing?

Ah, do me a favor and let me know what zip code you might try this in so I can be far enough away to see the fire ball, not be a part of it!

Personally, I wouldn't want to have anything to do with an engine that uses gasoline and produces an open flame. That includes those old pulse jet engines too!

Gasoline in a turbine - that would give a whole new meaning to the term "hot start!"

Bob

Well Bob, I hear 'ya. But why should our model turbines be any different that full size?. They can use gas.

Jet A and gasoline are completely different fuels, with different flash points, composition, combustion properties, etc. They have a completely different amount of refinement from the crude stock they both started as, etc. Jet A is actually kerosene.

I fly full scale planes with 100LL and have never heard of or seen jets at the airport use gasoline or 100LL. And you wouldn't catch me anywhere close by if some knuckle head tried to. But anybody that flies a jet (at least full scale) knows you just don't do that anyway.

you can refer to this earlier thread-lots of good info in it that states that full scale turbines do run just fine of gasoline. I would guess that the reason that you dont see it at your airport is that Jet-A is twice the price. Scott
http://www.rcuniverse.com/showthread...359&forumid=26]

Im pretty sure that our CFM-56 engines at work would burn up the turbine section rather fast, but I guess its all about the design of the engine.

SJ.

I have no doubt that a turbine could run on gasoline - or most any flammable liquid, if it were tuned to do so. How well it would do so and how efficient it would be is another question.

The real problem I have though in the models is that I almost always get some fuel in/around the model besides inside the fuel tank, despite how careful I am. In addition, I quite often get externally visible flames from the tail pipe when starting my JetCat. With gasoline, those two factors spell barbecue. In addition, after an aborted start that occurs because the gas tank is not fully charged or the glow plug is bad, the next start attempt could result in a real "bang!"

Bob

Shoestring:
Well i don't know who "anybody that flies full size jets" is but this anybody flew Falcon 20's for years and used avgas many times when jet fuel was not available. i also flew the military C-123K which had 2 recips and 2 jet engines and the only fuel we ever used was aviation gasoline.

JP-1 was mostly gasoline and JP-4 is mostly Naptha which is close to gasoline. Jet A, A-1 & JP-8, K-1, etc. are a higher density distillate skimed off at a higher/narrower temperature.

On the full size engines, it's a matter of a fuel control adjustment and tolerance to higher operating temps. When I was flying Air Force OV-10's the ground school guys were careful to point out the screwdriver adjustment on the fuel control (accessable in the wheel well) where you could set it for the fuel you were using. Just needed to be aware the different operating limitations.

Nobody uses off nominal fuels these days since the normal stuff is widely available and there's little testing for such. Even the US Army went to a single fuel for all its vehicles - ground & air. But it could be done in an emergency. As for our turbines, I doubt it since the metering for startup and running is really only setup for the vaporization characteristics of standard jet fuel.

Well Captainbob I stand corrected.

But when it comes to my Piper Turbo Saratoga I am staying with 100LL. I know that wont run on Jet A (at least not for long), even if they can use my type fuel. Although at $2.92 a gallon for 100LL, jet fuel is nice and cheap.

As you state it can and has been done, what is preventing you from using it in the model? What or whose info is keeping you from that?...just curious

Pilots,
the PT6 turboprop engine can be run on gasoline - but you are supposed to do a hot section inspection every 100hrs. with a borescope and mix 1 quart of Exxon 2380 with each 50 gallons of gas because gas alone does not lube the fuel pump and fuel control unit like Jet A does . We used to run this mixture in our Twin Otter aircraft when we could not get Jet A .

Jackjet

I fly full scale jets and can tell you that we CAN use unleaded gasoline. But its not something we do on a regular basis if theres JP-8 to be had. Its listed as an alternate source of fuel. As far as general aviation using unleaded gas....isnt there a conversion kit you can buy that's FAA approved that would let you use unleaded gas? Thought one of my instructors had one when I was getting my privates. I dont see it as a big deal, but Im sure that constant use will wear the engine down faster than you'd like


Luis

Shoestring,
Yes, a turbine will run fine on avgas but a piston engine will not run at all on kerosene. ask Bob Hoover.

I would like to run my jet on gas but im not willing to take a risk in damaging a $3500 engine. I want to get the blessing of a manufacturer or someone who's done it before.

A friend of mine is a certified mechanic on AS350-choppers, and hr told me that the AS350 can be run on 100LL for 20 minutes, but then the engine has to get a complete overhaul due to excessive heat.

Captain,

You're never going to get that (at least if I was a turbine manufacturer, I'd never give it to you). All of the comments here are about if it can be done in full size and if its safe for the turbine. That's not the right issue. The issue is that gasoline is not a SAFE fuel in model turbines. You're asking for a disaster if you try it!

Its bad enough having the Propane around, but its a very small quantity and dissipates into the air very quickly. Gasoline when spilled is much more volatile and hangs around as an ignition source for DAYS.

Bob

I'm in a pedantic mood.

I do believe that spilled gasoline would not be an ignition source. It would be an accelerant. Something else (a match, a cigarette butt, a wet starting turbine, a hot chick walking by) would be the ignition source.

Be that as it may, you are quite right. Spilled gasoline and model turbines are not a good mix.

...jim

pe·dan·tic Pronunciation Key (p-dntk) adj.

Characterized by a narrow, often ostentatious concern for book learning and formal rules: a pedantic attention to details.



Ah, whipping out the big words on a poor humble enginerd!

'Tis true, it is an accelerant, not an ignition source - its a damn good one too and I don't want to be on the flight line when someone gets a wet start on a model turbine powered with it! Not unless I'm far away and have my weenies ready to roast

Bob

Someone mentioned flash points being different for jet-A and gasoline.
Just a reminder, gasoline does not have a flash point because it can flash or fire at any temp.

95% Gasoline + 5% Oil=Let natural selection do it's thing. Great
way to clean those recessive genes out
of the turbine-waivered gene pool!

I think that's why we don't see many Japanese micro-turbine engineers. Remember the Sophia Coleman Fuel no-propane autostart? One too many Coleman fuel can tip-overs, and there went that gene pool!----must admit, that's just a rumor.

Tom

It does most certainly have a flashpoint...

AVGAS 100LL has it's flashpoint at -40 degrees Celsius, and Jet-A1 has it's flashpoint at +45 degrees Celsisus. These are of course textbook-values, so differences may occur in real life as the fuel rarely is exactly the same as the textbook-fuel..

Just to get the facts straight....

Don't feel bad Bob, Jim's just a REALLY TALL computer geek.

Ed
Just an other enginerd

I am not really tall.

Everyone else is short.



...jim

HUMMMM.. He can cast a shadow a mile long, but if you turn him 90 degrees, he disappears!

Ed