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Mogas use and E-10 warning

Not using E85 on aircraft does not disqualified me from speaking about first hand experience with my 2010 Ducati 1198s. Long list of issues among the most noticeable and costly.......swelling of gas tank, corrosion on the EFI throttle bodies, cylinder head corrosion, low compression due to pitting corrosion on cylinder walls, crank bearing corrosion, etc.... All just 2500 miles and thankfully under warranty. Ducati just settled a law suit to life warranty deforming swelling gas tanks in the US......i have owned ducati,s since the 70's and never and issue with all mentioned. Since all gas station are pushed to sell E85 even at the higher octane ratings, you have no choice now days...japanese MC,s have same issue
 
....and so do the Mercury outboards!

The outboard shops looove E-gas...brings them a lot of engine business, as I was told by them, this weekend!

Best,
 
Our fuel outlets have warning labels on Ethanol blend fuels warning not to use in marine or aviation applications unless the manufacturer approves its use.
 
Not evidence, but interesting.

My wife and I own a couple ATVs, both have carbs. Her ATV is air cooled and mine is water cooled. We only have E10 locally, so that is what we run. The ATVs often sit for a very long time (at much as 6 months with gas in the tank - carb run dry - stabil added). Both ATVs will run just fine on the old gas. I have been into the carbs on both and they were spotless with zero sign of corrosion.
 
frankh said:
Greg I can tell you right now the symptoms you saw are classic vapour lock.

So now lets say you try to take off on a really hot day at a high elevation airport..Your fuel flow is at a maximum..and your electric fuel pump quits on take off.

Your mechanical pump could immediately vapour lock and your engine might quit.

In other words under the most critical conditions you might as well just have a single electric fuel pump cus thats all you got anyway!

Thats why I run redundant electric pumps and have one away with the mechanical pump.

You could improve the situation by using a cooling blast tube and shroud on the mechanical pump.

Its a bandaid to a poor hydraulic solution but if like most flyers your married to the mechanical fuel pump its better than nothing.
Click to expand...

frankh - Thanks for confirming my suspicions of vapor lock. I have experienced it a couple times on the ground during a hot start, but never really in the air. The only problems that I?ve seen are above ~14,000ft where I almost never fly. I?ve got about 800hrs on my bird over the past 4 years and have run about 400hrs of 100% MOGAS. For a long time, we could get E0 all over NC, but then it all but disappeared about 1.5yrs ago. Now it?s starting to pop up again so I?m going back to it.

As others have mentioned, my engine seems to be much happier on MOGAS. The plugs stay cleaner, engine runs smoother, etc. The only thing I don?t like is the smell and limited airport access.

I like having one mechanical pump and one electrical pump on my setup. I do the same thing with my ignition system with one mag and one electronic ignition. This gives me at least one complete system that is independent of the electrical system. You never know when the errant EM pulse might come through and take out two electrical fuel pumps. Then where would you be? ;-) But seriously, what would happen if your battery ground strap broke off on a one battery system?

I?m sure good arguments can be made for many different setups, but I think it ultimately comes down to your mission and perceived risk comfort level. For me, I like the mechanical backup. It has worked well for a long time and I am learning its limitations. If I decide to fly out West or up into the flight levels, I?ll just fill up with AVGAS next time.
 
RV experience anyone?

No doubt, there is a mountain of evidence that will keep most people away from mogas when it comes to uses in anything from boats to motorcycles and lawnmowers.
I have yet to hear from an RV pilot that has used ethanol mogas and found any kind of corrosion problems in the fuel system. To the contrary, I have first hand knowledge ( not experience) of an RV4 pilot that has used E10 for the last 1200 hours without any problems.
I am aware that ethanol mogas will not be a one fits all solution but for our RVs its definitely a usable choice.
Please report if you know of, or have had a corrosion problem due to ethanol mogas in your RV.
Vapor lock is an issue and can be addressed in several ways.
 
N427EF,

My carbed RV-4 has run E10 for about 900 hours (first flight in 2000). I had to rebuild the carb at last condition inspection because the boost pump packing was leaking. The inside was clean as a whistle. I have had to replace the o-rings on the tank drains a handful of times but nothing else. What's funny is I filled up with 100LL one day when I was out and my right tank started leaking. The builder of my -4 painted between the tank and the inspection plate gasket. The 100LL ate the paint away and caused a leak. Fixed with a Scotchbrite wheel and some new tank sealant as a gasket.

My hangar mate has run E10 since he purchased his -4. He has about 1350 (500 flown by him, first flight in the mid 90's) hours on it and the only problem he has ever had with the airplane is a jug cracked. Come to find out the jug had been welded by the previous owner and it just gave up. He inspected his cam when the jug was off and it was almost perfect.

Yes, it's anecdotal but it's also real world.

I'm not telling you to go either way. We are all big boys and should be able to make our own decisions on this subject.
 
Hi All

Since many people claim to have run ethanol containing Fuel without a problem, here is what I had to go through:
I have run mogas in my RV-4 for seven years now. I like the clean plugs and the price. However, whenever I cut the power to idle, while the Oil was above 200F, it ran rough. I tracked the problem down to the little amount of ethanol (2%-3%), the Winter-Mogas contained. With Avgas or non ethanol Mogas, it was gone. The percentage of ethanol was determined using a feul tester. When the ethanol was below 1 %, the engine ran without issues. At percentages between 1% an 5%, I had the "hot Oil- low power (feul flow)" roughness. At ratios between 5% and 10%, the engine would loose power and run extremely rough at idle. One time, I trusted the statement of the pump guy and accidently got E10. The engine ran fine for the first 5 Minutes, then roughness occured. It lost power leading to a forced landing at the airfield I took off from. The engine finally quit at flare.

fly save

Thomas

http://www.rv-4.de
 
Vapor lock?

Frankh, help us out.
What Thomas describes appears to be a text book vapor lock issue.
Can you describe your fuel system for us.

Did you have any material compatibility issues? Corrosion, anything else?
 
Thomas Lukasczyk said:
Hi All

Since many people claim to have run ethanol containing Fuel without a problem, here is what I had to go through:
I have run mogas in my RV-4 for seven years now. I like the clean plugs and the price. However, whenever I cut the power to idle, while the Oil was above 200F, it ran rough. I tracked the problem down to the little amount of ethanol (2%-3%), the Winter-Mogas contained. With Avgas or non ethanol Mogas, it was gone. The percentage of ethanol was determined using a feul tester. When the ethanol was below 1 %, the engine ran without issues. At percentages between 1% an 5%, I had the "hot Oil- low power (feul flow)" roughness. At ratios between 5% and 10%, the engine would loose power and run extremely rough at idle. One time, I trusted the statement of the pump guy and accidently got E10. The engine ran fine for the first 5 Minutes, then roughness occured. It lost power leading to a forced landing at the airfield I took off from. The engine finally quit at flare.

fly save

Thomas

http://www.rv-4.de
Click to expand...

Vapour lock?

Were you running th boost pump when it ran rough at idle?
 
Vapour lock?
Click to expand...

Absolutely, I do suspect the mechanical fuel-Pump since switching on the electrical boost pump has never helped much. The mechanical pump is blast cooled. My fuel system is very basic without a vapour-return-line. There is no gascolator and the boost-pump is located inside the fuselage. All I am saying is that I made the experience that ethanol greatly increases the chance of vapour-lock. Avgas has never been a problem, even with higher Oil-Temperatures, Outside-Temperatures or heat-soak-situations. I had to look inside the fuel-tank recently and there was no corrosion.

Thomas
 
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N427EF said:
Frankh, help us out.
What Thomas describes appears to be a text book vapor lock issue.
Can you describe your fuel system for us.

Did you have any material compatibility issues? Corrosion, anything else?
Click to expand...

There is a lengthy description that I posted a while back..Just search under my name and you will see it.

Basically I have two wing root mounted high pressure electric fuel pumps (fuel injection). The filter, pump and pressure regulator plus return are all in the wing root.

I don't have a fuel selsctor..the output of both pumps just tee together, then I have an on/off valve in case of a forced landing, but I never turn it.

Tanks are switched by switching the appropriate pumps. Both are run for take off and landing.

Care has to be paid to how the pumps are supplied electrically.

Mechanical pump is deleted.
 
Other option

What Frank described is probably your best option to avoid vapor lock problems.

Almost all the mogas that is being used in airplanes these days contains at least 10% ethanol. The problem is not the ethanol but a fuel system that may or may not be compatible.
If you prefer to keep your mechanical fuel pump you must have a fuel/vapor return line. It simply involves a T fitting out of your mechanical fuel pump where approximately 6 GPH of constantly flowing fuel returns to the tank.
The pump delivers enough flow to afford the loss of 6 GPH and fuel pressure and metering is done down the line just before the carb or the injection servo.

This constant flow set up insures that you have a constant trickle of cool fuel added to your pump and in the unlikely event that vapor forms, an easy escape. Some of us simply prefer the mechanical/electrical redundancy of this set up versus electric only.
I am not trying to sell the the idea to anyone but it has been successfully used by many others before me.

Incidentally, trying to stay on topic ,here is an example of E10 mogas definitely not working in an airplane.
Ironically, this poor fellow has an automotive engine in his airplane and a fiberglass tank. His tank became soft after using mogas and he now has to use 100LL.
 
Ernst - Just for curiosity You take the vapor/fuel off of the outlet side of the mechanical pump and pipe it back where??? To the tank?? To the selector? What size orifice and line would you use??
 
Back to the tank

The orifice is a # 72 drill hole.
I flow tested this orifice on both of my airplanes to be sure the flow was were I wanted it. Anything between 4 and 8 GPH seems acceptable.
For flow test, hook up to a garden hose, set pressure to 25psi and run water into a bucket for measurment. PM me if you want all the details and pics.
I have a AFP injection were a purge line from the spider is plumbed back to the tank. The overflow from the mechanical pump is t'd into this line.
Andair sells a fuel selector valve that selects and returns fuel to the same tank, easiest solution.
Instead of the expensive quadruple valve from Andair
I used Van's kit supplied valve for the return selector and Andair for the main fuel supply valve.
On my previous airplane, I never touched the return selector just always had fuel return to the left tank. On the 10 running mogas in the right tank, I switch both at the same.
A little added complexity but a lot of new options like transferring fuel from one tank to the other and the ability to test mogas in one tank and being able to select 100LL if you have doubts.
 
N427EF said:
The orifice is a # 72 drill hole.
I flow tested this orifice on both of my airplanes to be sure the flow was were I wanted it. Anything between 4 and 8 GPH seems acceptable.
For flow test, hook up to a garden hose, set pressure to 25psi and run water into a bucket for measurment. PM me if you want all the details and pics.
Click to expand...

Ernst, since fuel pressure is much lower for carb setup, and my Facet pumps are rated for 4-6 psi at 30 GPH, should I set up the return line for a lower flow rate?

Robin
 
E10

molson309 said:
I put E10 in a Honda portable generator. After sitting all winter the generator would not start, and when I disassembled the carburetor I found extensive corrosion in the float bowl, which had clogged up the jets. I cleaned the carb and have since used non-ethanol gasoline, which has not caused a repeat of this problem.

Also had a dirtbike that required a carb cleaning after leaving ethanol gas in it over the winter.

No more ethanol gas for me in anything that doesn't get used regularly. Too much potential for corrosion.
Click to expand...

This was likely due to water in the carb for an extended period. I have seen this type of described corrosion with regular straight gasoline when water is in it.

Just saying I would not completely blame E10, although the E10 will absorb water, I have been told.
 
For a carburetor set up I would flow test the orifice at the pressure you are running. The whole purpose of the return line is to allow an exit so that a constant flow of cool fuel can be supplied to the less than ideal hot mechanical fuel pump. It needs to be large enough to be effective and not so large as to divert too much fuel from where it needs to go, somewhere between 4 and 8GPH .
I have no idea what the flow rate is of a mechanical pump but it supplies enough to run my IO-540 at 26.5 GPH on take off plus 6 gallons for the return and it does that without the electric boost pump.
If you plan on having your airplane sit around, I wouldn't put mogas in it.
There is simply no point in "not wanting" to use E10, nothing else exists in this state.
 
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