ethanol

[billmellett]

I'm brand new to the rotax concept. The lycoming and continentals that can run on auto gas aren't supposed to be run on auto gas with ethanol. The rotax engines obviously are being run on ethanol spiked gas. Is there anything that you have to do to the gas so that it does not pick up extra moisture? (My understanding is that is the problem with the ethanol. Could be wrong on that.)

[jamesmil]

ethanol contaminated gas will not only pick up water but will also attack the rubber in fuel hoses, carb,s and some fuel filter element materal.
also older fiberglass fuel tanks are not compatable with ethanol extended gas. it will cause all kinds of problems if stored for periods as short as 30 days in your airplane. it will also soften the pro seal used to seal fuel tanks on rv,s. this will show up at the inboard rear corner of the tank because that is the lowest point if it,s a tail dragger. then the tank has to be removed and the soft proseal has to be dug out till you get back to good proseal. were talking about 6 to 8 hores of work plus damaged paint around the screw heads. i put 10 gal. in my left tank on my rv7 once in a pinch to get to an airport along my route on a trip. topped off both tanks, when i got back home i was at about half tanks. did not fly again for about 30 days. not long after that is when the problems started. ethanol is junk!

[Esser]

Bill talk to Dave F he has been running ethanol in his Kitfox for a while now. I think the secret it drain your carbs when you are done flying.

[Woodennickle]

You can check for stations that have ethanol free gas at: pure-gas.org

[Dave S]

Oh Boy!

Talking ethanol again is not all that likely to result in complete agreement on the issue.

There is some information out there that can help a bit.

Rotax, as the engine manufacturer, explains that the engines can run up to 10% ethanol. They do not recommend any higher formulation of ethanol than 10%. I am pretty sure that if the manufacturer thought there was any issue with ethanol in their engines - you'd see a different recommendation. If rotax says 10% ethanol is OK in their engines. I can accept that as factual.

Aside from the engine - there is the rest of the fuel system - meaning the hoses filters and the fiberglass fuel tanks. The thing that does not seem to be ethanol proof in some cases is the fiberglass fuel tanks or linings that may be used in the tanks.

I have a friend with a Skyranger where he has a 912ULS, SAE hoses and a poly rather than fiberglass fuel tank. He runs only 91 auto with 10% ethanol - never a glitch.

On the issue of compatibility of the hoses with ethanol - that again is pretty much a matter of the hose manufacturer's specifications. Certainly SAE hose is designed to handle ethanol. Since I took a while to build our plane - I also took the time to cut off 1" sample pieces of milspec, SAE standard and SAE FI hose and let them steep in AVGAS, corn free MOGAS 91octane and 10% corn gas 91 octane - for a year in sealed bottles - know what? - none of the hoses swelled. My explanation is that when hoses do swell up or swell shut it has to do with either: 1) contaminants in the fuel (which is more common in autogas of any formulation because of how it is handled); or, out of specification materials used in the hose (i.e. cheap stuff of dubious quality).

So what do I run in mine? 91 octane corn free autogas; or, 100 LL when I can't get the 91 non ethanol auto fuel.

Ethanol has approximately 60% of the energy gasoline - meaning that ethanol reduces your range. That's simply a matter of chemistry. With 10% ethanol - the effect is rather minor but it still will reduce your range by approximately 0.4% compared to corn free gas.

One thing that I find irritating about the issue is the insistence on the part of the ethanol industry of referring to ethanol laced fuel as "Oxygenated" - it is true that there is chemically combined oxygen in ethanol while there isn't in gasoline - but this claim is purely marketing hype attempting to paint an environmentally friendly face on the product because it has "oxygen" in it - the practical way of looking at this is the fact that since ethanol contains chemically combined oxygen - it reduces the amount of carbon and hydrogen available for combustion - i.e. - worse fuel economy per gallon......

Personally I stay away from the 10% corn gas since my fuel tanks are not of the latest design.

Sincerely,

Dave S

[billmellett]

Wow! Great information. Thanks everyone.

This map is really interesting. I can fly from the D/FW metroplex to Laredo, TX and never cross anywhere with ethanol-free mogas without going way out of the way. That's a bummer.

http://pure-gas.org/extensions/map.html

[Paul Z]

Get the Alcohol Out Read my post about the issues I had with Alcohol in the fuel! Not worth the savings, or not worth the EXPENSE!!!!!!! I got to spend a lot of time and dollars rebuilding Carbs and flushing tanks because it stripped epoxy out of the tanks and through the Carbs!

[DBVZ]

A related issue is that some have reported that stations reporting ethanol-free gas may sometimes have ethanol anyway. Not supposed to happen, but delivery trucks show up and drop fuel, and the station operator may not even know. Or may know and not care. And testing a sample each purchase is kind of a pain. You have to have the right stuff to do the test, and take the time to do it.

[Av8r3400]

Bill talk to Dave F he has been running ethanol in his Kitfox for a while now. I think the secret it drain your carbs when you are done flying.

Ethanol is a bad idea on so many different levels, I don't think you'll get any argument about this.

In the case of Dave, I have wondered aloud several times if the blend of ethanol and other garbage additives is different in Canada than here in the US, which could explain Dave's lack of problems.

Maybe, it's not just the ethanol, but a combination of ethanol and some of the other EPA mandated additive(s) which are responsible for the damage we have seen in the fiberglass tanks.

[Esser]

The whole ethanol thing in Canada is a joke. It is yet another follow what the US is doing feel good factor. From the best of my knowledge the US implemented the ethanol garbage to start relying less on foreign oil reserves. Now Canada has the second largest oil deposits in the world after Saudi Arabia. So why did Canada implement the same policy? I have no idea. Especially since it has been proven over and over again that corn based ethanol is more damaging to the environment. So really it is just a big pain in the butt for us that does nothing for the environment. Now apparently the only gas in Ontario that is ethanol free is Shell V-Power. But Dave tested it in one of his videos and it had ethanol in it. I'm afraid the government once again played the stupidity card.

As for testing for ethanol it is not that hard, all you need is a test tube with two lines on it. fill the tube up with water to the bottom line, then fill up with fuel to the higher line. Shake it all up and look. If the water is still at the bottom line you have no ethanol. If it looks like some how there is less water in the tube then you do have ethanol. It is a pain but it only takes a minute.