Alternative fuel for experimental aircraft?

[LAXSaabdude]

I believe that the FAA prohibits the use of any ethanol in any aircraft engines that are certified to run on mogas (i.e. Continental/Lycoming).

Now here's a question. If one was to build a VW powered experimental aircraft, could you run it on a gasoline/ethanol mix? Assuming, of course, you took care of all of the physical details - rubber seals, anything that may deteriorate with ethanol.

Just how much latitude does the "Experimental" designation get you as far as fuel goes?

Thanks.

LAXSaabdude.

 

[MAJIC9]

you can put anything in it... even coal, if you'd like

 

[USMCmech]

You SHOULD run the engine on whatever it was designed for.

however,

The FAA dosen't know or care what you run your engine on if it pulling an experimental airplane.


There is no STC for experimental aircraft at all. So, if you are flying behind a conventional aircraft engine and want to run mogas (which is perfectly harmless in most smaller engines) you should just research wether that engine has a mogas STC or not. If so, then go ahead.

 

[Swede]

My only foray into GA (I hope to do so again someday; something about flying for fun is really appealing) was a Grumman AA1 with a Lyc. 4-banger. I had it STC'd for MoGas. It actually preferred the Exxon super to 100LL, as leading wasn't an issue. The FBO hated me though because I wouldn't by his crummy expensive 100LL.

Given the cost of fuel, I wouldn't hesitate to STC any engine that can take mogas. I think the "problems" that are supposed to happen are BS rumours. Maybe someone with more GA experience can correct me.

These guys are correct, experimental engines have lots of latitude for fuel.

 

[avbug]

Merely because you can do it, doesn't mean you should.

EAA et al did nobody any favor by pushing through the autofuel STC program.

 

[USMCmech]

Avbug and I disagree on mogas which is fine, but you should always look at all sides of the arguement.

You SHOULD run the engine on whatever it was designed for.

Smaller GA engines like the O-200 O-320 ect were designed for 85-87 octane Avgas. 100LL is overkill and leads to lead fouling on the plugs.

Mogas is just fine for these engines.


TIO-540s on the other hand need all that lead in 100LL to prevent detonation. Older large engines (radial and inline) from the WW2 era were desigened to run on the 115/130 purple Avgas. These engines must be run at lower powersettings because the antiknock properties in 100LL are not sufficent for long term use.

 

[LAXSaabdude]

Thanks, everyone for the replies. To be a little more specific, though, I was digging around on some non-aviation related alternative fuel sites (a big interest of mine lately), and I saw a how-to article about converting a VW engine to run on a blend of 85% ethanol / 15% gasoline. The main concern seemed to be with ensuring that certain parts dont erode from the ethanol content.

The article piqued my interest, knowing that a lot of smaller experimentals run on VW engines, and I was wondering if this conversion could be put to use in an aircraft. I was also aware, though, about the FAAs prohibition of using ethanol-infused mogas in aircraft engines and was wondering if they would take issue with an ethanol-powered VW engine.

LAXSaabdude.

 

[USMCmech]

The article piqued my interest, knowing that a lot of smaller experimentals run on VW engines, and I was wondering if this conversion could be put to use in an aircraft. I was also aware, though, about the FAAs prohibition of using ethanol-infused mogas in aircraft engines and was wondering if they would take issue with an ethanol-powered VW engine.

If it on an experimintal airplane, the FAA dosen't care if it's powered by hamsters.

On production aircraft, that blend of mogas is forbiden.



If the VW engine runs OK with that alternative fuel, then you as the aircraft builder have to make a risk assesment wether or not you want to use it.