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Mogas E10, Successful alternative fuel!

N427EF

Well Known Member
Maybe it is time to revisit the mogas discussion.
With avgas prices down between 3 and 4 dollars, we mogas users are seeing
fuel prices at around $2.50 for 91 Octane E10.
Many of us have successfully used 91 Octane mogas with ethanol and found no adverse effects of any kind.
As with the many old wife's tales recently discussed in this forum, perhaps
more of us will lean towards building an ethanol tolerant fuel system.
All of the low compression engines, 8:1 or less, can easily burn 91 octane gasoline and with very little modification can also tolerate ethanol.

While there may not be much incentive with avgas prices hovering at less than 4 dollars, the time will come again when avgas fuel prices go back up to 6 or 7 dollars.
You can be pro active and build for the future or wait for the guvmt. to bring
you very expensive alternative 100 Octane avgas.
 
Maybe it is time to revisit the mogas discussion.
With avgas prices down between 3 and 4 dollars, we mogas users are seeing
fuel prices at around $2.50 for 91 Octane E10.
Many of us have successfully used 91 Octane mogas with ethanol and found no adverse effects of any kind.
As with the many old wife's tales recently discussed in this forum, perhaps
more of us will lean towards building an ethanol tolerant fuel system.
All of the low compression engines, 8:1 or less, can easily burn 91 octane gasoline and with very little modification can also tolerate ethanol.

While there may not be much incentive with avgas prices hovering at less than 4 dollars, the time will come again when avgas fuel prices go back up to 6 or 7 dollars.
You can be pro active and build for the future or wait for the guvmt. to bring
you very expensive alternative 100 Octane avgas.

Ernst,

What changes (if any) did you make to your fuel system to better tolerate E10?
 
Softening Proseal 890 is an issue. Company engineer told me its not been tested and tho it is ethanol "resistant" its not ethanol proof. A rain resistant poncho just doesn't cut it in a downpour.

As usual, everyones mileage seems to vary.
 
MoGas

I've been using 93 Octane E10 for almost three years. I get it from a local Shell station near KBKV and have found that it contains little of no alcohol. The only difference in operation is that the engine starts a little differently with the E10 Vs 100LL. I have not seen any difference in vapor lock issues between the E10 and 100LL here in the summer Florida heat.

I have an IO-360 (two PMAG's) with teflon hoses in the engine compartment. I have not seen any softening of the proseal in the tanks. But I did have to change the "O" rings on the quick drains as they were not ethanol compliant....


Maybe it is time to revisit the mogas discussion.
With avgas prices down between 3 and 4 dollars, we mogas users are seeing
fuel prices at around $2.50 for 91 Octane E10.
Many of us have successfully used 91 Octane mogas with ethanol and found no adverse effects of any kind.
As with the many old wife's tales recently discussed in this forum, perhaps
more of us will lean towards building an ethanol tolerant fuel system.
All of the low compression engines, 8:1 or less, can easily burn 91 octane gasoline and with very little modification can also tolerate ethanol.

While there may not be much incentive with avgas prices hovering at less than 4 dollars, the time will come again when avgas fuel prices go back up to 6 or 7 dollars.
You can be pro active and build for the future or wait for the guvmt. to bring
you very expensive alternative 100 Octane avgas.
 
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I recently had to rebuild the carb on one of my Honda generators after leaving auto fuel in it for four months. I was surprised to find as much water in the small tank as I did. Even worse was the corrosion I found on the bowl and other parts.

While I'm a fan of auto fuel, this E10 garbage MUST go, it is bad for the environment, food prices, and equipment!

Besides, as pointed out by the OP, fuel prices have come down; burn pure auto fuel or 100LL. (We can buy non-ethanol gas at our local gas station.)

Ethanol was brought to us by the same idiot paper pushers who gave us MTBE in our gas, which contaminated ground water all over the country.)
 
I recently had to rebuild the carb on one of my Honda generators after leaving auto fuel in it for four months. I was surprised to find as much water in the small tank as I did. Even worse was the corrosion I found on the bowl and other parts....

Same thing I found with my small engines. I think the problem is that the fuel tanks on lawn mowers and our RV's are vented to the outside and "breathe" with temperature changes, as in the difference between day and night. Each overnight, the tank pulls in outside air, complete with whatever moisture is present. The alcohol absorbs that water until it's saturated, and then drops out and causes corrosion and jello-like sludge too. Modern automotive fuel systems are sealed and don't let in outside air.

And we can't easily seal the fuel system on our RV's like cars do because of the tanks' need to equalize the pressure differential or they would either implode or explode from altitude changes. Automotive fuel tanks are much more robust and can tolerate significantly more pressure differential.

So, I suppose if you fly often and not let the E10 sit too long, that's the key to success.
 
I want everyone to know that E10 has been a successful fuel for my IO-540
for the last 3 years and 300 plus hours of trouble free operation.
I also have friends who have used the same fuel without any problems even without any modifications to the fuel system.
My biggest ethanol mentor is the Vanguard squadron that has been burning pure ethanol or any combination of avgas mogas and or ethanol in their RVs for nearly 20 years with little or no modifications to their RVs

Comparing lawn mowers and other small engines made by the Chicoms is simply unrealistic when looking at a state of the art Lycoming and a proven and ethanol tolerant fuel injection system such as AFP and others.

While I'm a fan of auto fuel, this E10 garbage MUST go, it is bad for the environment, food prices, and equipment!

I agree with you but why spend your efforts getting mad with guvmt policies when you can easily take advantage of what the fuel can do for you.
Apart from the price it keeps the engine and plugs wonderfully clean.

What changes (if any) did you make to your fuel system to better tolerate E10?

I installed a constant flow fuel return system. It is very simple and the only purpose is to constantly introduce cool fuel to the fuel system to keep vapor lock from developing.
I also replaced the o rings on the quick drains with ethanol tolerant rings.

Softening Proseal 890 is an issue. Company engineer told me its not been tested and that it is ethanol "resistant" its not ethanol proof.

Tell the engineer it has been tested by many experimental aircraft builders
and after burning through nearly 2000 gallons of ethanol fuel, the tank sealant looks as good as new.
I am aware that this is not acceptable to the certified world but is most certainly good enough for experimental aviation.
 
Glad for this discussion

I have been considering crossing over to the dark side and using 91oct e10. I can save over 2$ per gallon over 100LL. I used Mogas in my 0-300 powered 172 for years with no negative issues whatsoever and am currently using pure 91 oct. in my O-320 powered RV-6 but I have to fly 50 mi to get it and it's still $3.25 gal.. I can get 91 oct e10 for about $2.70 at the local gas station.

What scares me is the report I read from some European University that stated once ethanol is introduced into an engine it sets into motion corrosive activity that can never be abated even if ethanol is never used again. I have no desire to introduce corrosion into my engine but at the same time I realize millions of auto engines are running on E10 and no draconian effects have been noted.

One question I have is if pure ethanol is diluted by Mogas by a factor of 9:1 does the corrosive nature of the ethanol get reduced by %90? Or is the corrosive nature of ethanol impervious to any dilution? I hope I'm not showing off my lack of chemistry knowledge but my inquiring mind wants to know.
 
Softening Proseal 890 is an issue. Company engineer told me its not been tested and tho it is ethanol "resistant" its not ethanol proof. A rain resistant poncho just doesn't cut it in a downpour.

As usual, everyones mileage seems to vary.

If it hurts when you do that, then don't do that! (Use Proseal 890.)

Seriously, the current Flamemaster formulation that Van's sells is rated to be immune to ethanol; it's safe for all mogas. I checked the data sheet before building my tanks.

Charlie
 
Softening Proseal 890 is an issue. Company engineer told me its not been tested and tho it is ethanol "resistant" its not ethanol proof. A rain resistant poncho just doesn't cut it in a downpour.

As usual, everyones mileage seems to vary.

Hmm....that's interesting. The spec sheet says it is impervious to alcohol.
 
Old wife's tail

One question I have is if pure ethanol is diluted by Mogas by a factor of 9:1 does the corrosive nature of the ethanol get reduced by %90? Or is the corrosive nature of ethanol impervious to any dilution? I hope I'm not showing off my lack of chemistry knowledge but my inquiring mind wants to know.

Not really that old but the corrosive nature of ethanol blended fuel was introduced in the first few years of using ethanol, when according to
industry experts the acid content of manufactured ethanol was not controlled.
In those days, the acid content was several hundred times higher than ethanol introduced into today's mogas.
The most vulnerable engines were cheap little lawn mower and weed whacker
type engines with inferior alloys used for carburetors and such.

That European study is old and useless when comparing with today's ethanol fuels.
We know that Tetraethyl lead (TEL), is horrendously toxic and damaging to our engine components such as valve guides and spark plugs and yet everyone is
happily using it.
Maybe it is more comfortable for people to deal with a known devil vs. an unknown one.
 
I have been considering crossing over to the dark side and using 91oct e10. I can save over 2$ per gallon over 100LL. I used Mogas in my 0-300 powered 172 for years with no negative issues whatsoever and am currently using pure 91 oct. in my O-320 powered RV-6 but I have to fly 50 mi to get it and it's still $3.25 gal.. I can get 91 oct e10 for about $2.70 at the local gas station.

What scares me is the report I read from some European University that stated once ethanol is introduced into an engine it sets into motion corrosive activity that can never be abated even if ethanol is never used again. I have no desire to introduce corrosion into my engine but at the same time I realize millions of auto engines are running on E10 and no draconian effects have been noted.

One question I have is if pure ethanol is diluted by Mogas by a factor of 9:1 does the corrosive nature of the ethanol get reduced by %90? Or is the corrosive nature of ethanol impervious to any dilution? I hope I'm not showing off my lack of chemistry knowledge but my inquiring mind wants to know.

I have never heard this before. My understanding from the auto world was that the primary issues with ethanol were 1) that it ate up the rubber seals used at the time of ethanol introduction. The material used up to this point was resistant to gasoline, but not ethanol. 2) corrosion from water absorbed by the ethanol. As mentioned earlier, this was a small issue, as most gasoline systems were fully closed by that time due to the aggressive emission regs and those that weren't were changed to support ethanol. I am unaware of any metallurgy changes made to accommodate ethanol.

Larry
 
Be careful using broad brush strokes.

It is difficult to say it is OK to burn E10 in all RV's because it worked fine in yours. Remember, since not all RV's are built the same, some may have issues while others not (unless you let the stuff sit in the tanks for a few months). Some have carbs and as we all know, which means the fuel will sit in the float bowl for long periods of time. In addition, the FAA doesn't like to let the carb manufacturers change gasket material without extensive testing and running through the approval process. Also, from what I have read on this forum, there are a number of people who have installed braided stainless steel fuel lines rather than bend aluminum tubing. Who knows if those lines are impervious to ethanol tainted fuel. What about the fuel valves, are they impervious? And which valve?

Saying that it is OK to run ethanol because the Vanguard Squadron does is like saying it is ok to run pure ethanol in my truck because John Force runs it in his 300 MPH race car. The Vanguard Squadron is a sales and marketing arm of the ethanol industry and thus, I have to look at what they preach with a bit of skepticism.

As for the "acid" content of E10 fuels being controlled, I'm not so sure that is true since It was this summer that I had to rebuild my generator's carb and the fuel in it was only about four months old.

When I go to sell my RV, you can bet that I will advertise it has never run on auto fuel of any type! If I were buying an RV, I would be very skeptical of any plane that has ever run on it.

The price difference between premium unleaded auto fuel and 100LL isn't that great, why risk it?
 
this E10 garbage MUST go, it is bad for the environment, food prices,

I'm an Iowa corn farmer and find your comment on food prices interesting. It seems to assume that if I could not sell corn for ethanol I'd sell it cheaper as food.

Right now, the selling price of corn off my farm is below the cost of production. Source is Iowa State University (soybeans are even worse). It's projected to be that way for several years as demand and supply adjust.

Please do not assume that if I sell corn below the cost of production when ethanol is part of the demand picture that I would sell it at even a greater loss if ethanol were not a corn user. In fact, I would almost certainly change my farming operation to grow something else that did make me money. What would that be? Well, it so happens that I have 150 acres in miscanthus x giganteus (MXG) that is a biomass fuel for the University of Iowa boiler plant. Not even deer can eat this stuff. All it's good for is chicken litter, cattle bedding and burning as an additive in coal fired boilers.

If corn lost the ethanol market, it would not necessarily translate into cheaper food over the long run. As you know, soybeans became a food crop in the 1930's, alfalfa became big in the '50s, and farmers are always looking for a good crop that makes money. We are not set in concrete that we have to grow corn. Corn became a big crop in the '20s and '30s after hybrid corn production as pushed by the land grant universities and parent companies of Pioneer DuPont, Monsanto, Syngenta and other grain giants.

BTW, corn is probably better for the environment than soybeans, which is the other big crop in the corn belt, so if less corn meant more soybeans that might reduce nitrogen inputs but would certainly increase soil erosion and would increase chemical herbicide inputs.

Corn used for ethanol has a by-product of distillers grains which are resold to livestock operations, so much of the corn value for feed is retained in a different form and still used as straight corn would be.

Thread drift over, just thought I'd offer some perspectives on whether reduction of ethanol demand would translate into cheaper food prices. It's a complicated subject.
 
Not really that old but the corrosive nature of ethanol blended fuel was introduced in the first few years of using ethanol, when according to
industry experts the acid content of manufactured ethanol was not controlled.
In those days, the acid content was several hundred times higher than ethanol introduced into today's mogas.
The most vulnerable engines were cheap little lawn mower and weed whacker
type engines with inferior alloys used for carburetors and such.

That European study is old and useless when comparing with today's ethanol fuels.
We know that Tetraethyl lead (TEL), is horrendously toxic and damaging to our engine components such as valve guides and spark plugs and yet everyone is
happily using it.
Maybe it is more comfortable for people to deal with a known devil vs. an unknown one.

Facts are important. All of the "old" ethanol was not high in acid, and there was a standard, but it was a batch test and small producers were not very good at the process, or just negligent. Here is a comment I made a while back - to avoid chasing a link, here is the post:

"The early ethanol plants (circa 1994) were not required to have a continuous monitoring system for acidic content. Cargill and ADM made 90% of all ethanol as an additive at that time. The manufacturing process adds acid to accelerate the mash fermentation process (like the old batteries in hillbilly stills) then a water wash process removes the acid. Some plants did not have good controls and allowed the acid laden ethanol out on the market. My engineering group worked with Cargill and ADM to propose, and get, the ASTM testing standard modified to make it a continuous process measurement rather than the batch process being used. This change pretty much eliminate all corrosion due to the ethanol content over the following 12 months that the standard allowed for compliance.

More background: At the time (mid 1990's) my engineering group was developing catalysts for large diesels that sprayed pure(denatured) ethanol in front of a catalyst bank to reduce NOx by 90%. We had field testing sites that purchased 10,000gal tanks of ethanol. The first one was ok, but then we started to eat up everything. Pumps especially. We had a 5 gal can of the stuff shipped back to us and it dissolved the chrome off the pull out spout of the 5 gallon can, and in the process of eating the container neutralized itself. Struggling for a while, I sent a guy with a glass container and brought a sample back. It was 500 times over the acid limit of the standard. yes, five hundred. So- the old tales of corrosion were true and were nearly impossible to trace. The large batch sizes and the fact that we stored it in stainless steel tanks kept the acid from neutralizing itself in normal steel tanks, allowing the team to get to the root cause.

PS: one must still ensure that elastomers are compatible and pressure/temp of fuel is adequate to prevent vapor formation, but corrosion should not be a concern."

There is a lot more to this than posted, but the fact what we were working directly with manufacturers of ethanol, and had purchased a large quantity, it gave access to data that was not available to GM, Ford, Chrysler and others. Their solution was to use stainless fuel lines and components. Even 1 gallon of bad mix was over the limit when mixed with several tanks of good fuel.

PS - It is not just raw corn used in the plants. According to the ethanol plant chemist ( a personal tour and many discussions), corn is broken down in to many different compounds, then sold as building block for other food stuffs. The constituent used in the production of ethanol, does not compete with the vast majority of food stocks. While it was long ago and I can not quote the components, they had a good factual case and I was convinced at the time of its validity.
 
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Industry expert

Thanks Bill,
it was your expert report that I based my comments on.
It does not get any better than hearing it directly from an industry expert.
 
The price difference between premium unleaded auto fuel and 100LL isn't that great, why risk it?

This is the only portion of your post I disagree with. Real (no ethanol) premium is currently $1.62/gallon cheaper than 100LL in my area. That's almost $13/hr savings at the 8gph I plan for. Over the life of the engine, that's enough to pay for an overhaul.

Completely agree with everything else you wrote - I won't use anything with ethanol as there are simply too many unknowns and anecdotal evidence for one RV doesn't necessarily carry over to other RVs due to build differences, etc.
 
It's been mentioned before many times, but for those who don't like the idea of running ethanol laced fuels in their planes, or anything else for that matter, look around and try and find a gas station that carries ethanol free gas for "recreation" vehicles. The station I get mine from charges about .50 cents more per gallon than their ethanol laced premium. I am still saving on average $2.00 per gallon compared to 100 LL.
 
<snip>

What scares me is the report I read from some European University that stated once ethanol is introduced into an engine it sets into motion corrosive activity that can never be abated even if ethanol is never used again. I have no desire to introduce corrosion into my engine but at the same time I realize millions of auto engines are running on E10 and no draconian effects have been noted.

One question I have is if pure ethanol is diluted by Mogas by a factor of 9:1 does the corrosive nature of the ethanol get reduced by %90? Or is the corrosive nature of ethanol impervious to any dilution? I hope I'm not showing off my lack of chemistry knowledge but my inquiring mind wants to know.

That is a very, very good question. I am not a chemist, but this discussion was had with one, several in fact. So - I was told (keep that in mind) and IIRC, ethanol itself cannot be acidic. But, the tiny amount of water within it can be acidic and very acidic. Apparently dilution by ethanol does not reduce the pH, but it does its ability to react when in contact with some metals does "consume" the acid. The example is that a 5 gallon metal container was filled with ethanol. It was very acidic when introduced, but over several days (in transit) it reacted with the container and completely neutralized itself. It tested neutral. When ethanol from the same batch was transported in glass, it was 500% over the standard via testing. 500% sounds worse than 5X doesn't it. This might be perfectly correct to you chemists, but the example and results are factual.

Typically, if the acid content was low, but still acid pH, then it was typically neutralized in the rail containers and your fuel tank. If it the acid/water content was too high or short transportation distance, or then quickly stored in a fiberglass underground container, then it remained potent. You can imagine the many transportation scenarios that complicate the results, thus so many varied experiences.

Anyway, this testing method should all be cleared up now with new standards in place since the 90's. Poor quality processes notwithstanding.
 
I won't use anything with ethanol as there are simply too many unknowns and anecdotal evidence for one RV doesn't necessarily carry over to other RVs due to build differences, etc.

We have now had a good 2 decades of testing with ethanol fuel.
How many decades of testing would put you at ease?
Would you feel better if big brother put his approval on it?

It is difficult to say it is OK to burn E10 in all RV's because it worked fine in yours.

Here is what I said and quite different from how you put it.
All of the low compression engines, 8:1 or less, can easily burn 91 octane gasoline and with very little modification can also tolerate ethanol.


Specifically I am pointing out "very little modification" and by modification I am referring to the fuel system. The engine does not need any modifications.
The most feared aspect of using low octane fuel is the dreaded vapor lock demon. A properly set up fuel system will not vapor lock.
Many options are available but in my case it is an AFP fuel injection system,
(approved for use with ethanol).
Since we no longer have to fear corrosion, stock aluminum fuel lines are ok
and Teflon lined stainless steel braided hoses for FF are standard as well.
This set up leaves you with 2 modifications. Exchange the o rings on the quick drains and install a constant flow return line.

I have yet to hear from someone who has had any kind of trouble with E10.
All of the voices against this fuel are from people who heard from someone that
it does not work but have never tried it in their own Lycomings.

I am not selling any parts or services but I have noticed that we as experimental aircraft enthusiasts are moving ever so slightly towards certified and approved installations and forget that we have the privilege to push the envelop a bit.
Not suggesting that you through caution into the wind and blindly try something that will put you at risk. I am simply telling you that E10 works very well for me and hundreds of others who have successfully used it for many years.
 
Ernst,
You missed (or ignored) my point completely. I said that in a VENTED fuel system (like RV's and lawn mowers), the simple act of the tanks' breathing from daily temperature swings draws in moisture which is absorbed by the ethanol. If you fly on a REGULAR BASIS (as you obviously do):
...for the last 3 years and 300 plus hours...
then you add enough NEW FUEL for that moisture to never be a problem.

...Comparing lawn mowers and other small engines made by the Chicoms

What you say about lawn mowers is completely irrelevant. Their fuel systems are no less sophisticated than
state of the art Lycoming
That's the funniest thing I've ever heard you say!

The point with the small engines is that they tend to sit for extended periods (like months) with the same fuel in the tank. That old fuel gets saturated with moisture (from the daily tank breathing) and then the ethanol/water mixture settles out and turns to jello which clogs the carb jets and causes corrosion.

Now, Ernst, since you fly all the time, YOU WILL NEVER see this sort of problem. The people who will have problems are the ones who let their airplanes (or lawn mowers) sit over the winter for months without starting the engine and adding fresh fuel.

The easiest solution is to drain the E10 and fill the tanks with 100LL when storing the airplane (or lawn mower) for the winter.

Heinrich
 
A properly set up fuel system will not vapor lock.

I have yet to hear from someone who has had any kind of trouble with E10.
All of the voices against this fuel are from people who heard from someone that
it does not work but have never tried it in their own Lycomings.

I'll assume you're referring to injected engines, but since you didn't specifically state it and your post otherwise seemed to imply that my fuel system is not properly set up....

I HAVE had trouble with mogas, and ethanol neither hurt nor helped the matter. My trouble was the rather the poorly-controlled, unpredictable, and most always high Reid Vapor Pressure of mogas in my lycoming-powered RV9A. Even ASTM-spec mogas has a wide band of RVP tolerance which varies by state and by month of the year. Great if you're running high pressure injection in a car or staying on the ground.

I'm not the only one, either. Just search the forum for the words "mogas" and "stumble" together, and you'll find multiple other cases of the exact thing. Warm engine from a previous flight, mogas in the tanks, unknown RVP (because unless you test every load, the RVP of mogas is ALWAYS unknown). The feeling of my engine acting like it's getting ready to quit less than 800ft off the runway is one I'll never forget. The fact is that 100LL is controlled to much tighter tolerances and has a higher RVP to begin with than most (all?) mogas blends. For me it's well worth the price to never have to experience that again.
 
That's the funniest thing I've ever heard you say!

A bit tongue in cheek but in the absence of anything better, a Lycoming is by definition, indeed state of the art.

Your points are well taken and I appreciate the responses.
However, I see that the only experience you have with ethanol is a
"Honda Generator" and none running it in a Lycoming powered airplane.

What you say about lawn mowers is completely irrelevant. Their fuel systems are no less sophisticated than

I beg to differ, first of all you brought up the Honda generator and secondly
I made reference to the inferior alloys used in some of those cheap installations not the sophistication of the system, making them vulnerable to
corrosion and deterioration.
You look at an AFP fuel controller "approved for ethanol" and one of those
third world carburetors that you can scratch up with your fingernails you would have to agree that comparing fuel controllers from weed whackers/generator etc. is no comparison to "state of the art" aircraft fuel injection systems.

I am still hoping to hear from someone who has had any problems running E10
in a Lycoming powered airplane, RV or other.
I am willing to bet the farm that none exists.
 
Operating with 93 Octane E10

I have been running 93 Octane E10 in my IO-320 for about 50 hrs. The two biggest issues I have seen are:

During high ambient temps (85 F plus), the 93 E10 definitely has a higher tendency to boil in the injector lines at low power settings such as taxiing after landing or after prolonged idle power approach followed by application of go around max power, there is a hesitation until the boiling fuel gets purged. Running pure 93 E10, this happens consistently at about 85 F and higher, getting worse the higher the temps are. Running pure 100LL raises the threshold to about 95 F before I get the same issues. But I know why this happens and deal with it.

The AFP fuel pump O-rings swell slightly when using 93 E-10 and cause the fuel pressure to be around 35 psi when the pump is on and the engine is running. Using pure 100LL, the O-rings in the pump return to "normal" and the pressure settles down to 28 psi.

Both of these issues have well understood cause and effect issues, if you can operate safely with them, so be it.

Other than those two issues, I have run 93 E10 without issue.
 
After 6 years and close to 600 hrs running mostly 87 octane the only problem I've had was the o-rings on the fuel sumps. Replaced them with viton o-rings. This is an o-320 e2d 7:1 compression with e-mags.I fly above 10k on a regular basis. The only time I run 100LL is when I'm on a trip and have to fuel away from home. The only other problem I see is my fuel flow on the GRT fluctuates, I talked to GRT and they said that was common with auto gas.
 
Maybe it is time to revisit the mogas discussion.
With avgas prices down between 3 and 4 dollars, we mogas users are seeing
fuel prices at around $2.50 for 91 Octane E10.
Many of us have successfully used 91 Octane mogas with ethanol and found no adverse effects of any kind.
As with the many old wife's tales recently discussed in this forum, perhaps
more of us will lean towards building an ethanol tolerant fuel system.
All of the low compression engines, 8:1 or less, can easily burn 91 octane gasoline and with very little modification can also tolerate ethanol.

While there may not be much incentive with avgas prices hovering at less than 4 dollars, the time will come again when avgas fuel prices go back up to 6 or 7 dollars.
You can be pro active and build for the future or wait for the guvmt. to bring
you very expensive alternative 100 Octane avgas.

Ernst are you certain the components of the Lycoming mechanical pump are compatible with ethanol?
 
Ernst are you certain the components of the Lycoming mechanical pump are compatible with ethanol?

Since Lycoming will not tell anyone what the internal components are made from, no, nobody can be certain. The only evidence that can be gathered is direct experience - which seems to indicate that (at least the more recently manufactured) materials are tolerant.
 
Ernst are you certain the components of the Lycoming mechanical pump are compatible with ethanol?

No, I am not!

I am looking at the vanguard squadron and their 15 plus years of operating
with a standard mechanical fuel pump and my concerns are none.
 
Since Lycoming will not tell anyone what the internal components are made from, no, nobody can be certain. The only evidence that can be gathered is direct experience - which seems to indicate that (at least the more recently manufactured) materials are tolerant.

A few hundred hours means nothing. You need to know and understand the chemical composition of the materials involved and their potential interactions. Also, Lycoming can't and won't change the materials used within their engines without going through some type of expensive certification process. Thus, it is possible that the materials used in your engine may be the same as those used over the past decades.

It is irresponsible to say it is OK to use something in your engine when it is unknown what the impact, if any, will be. I'll give you an example, some years back one of our South American members posted his experience running auto fuel with ethanol, as they were required to do. One of the issues they have is that their engine driven fuel pumps tend to have a limited life span. (I don't recall the length.) The solution was to keep an extra fuel pump in their hangars. That is not a solution and the thought of the pump going out while on a trip is not appealing.
 
Since Lycoming will not tell anyone what the internal components are made from, no, nobody can be certain. The only evidence that can be gathered is direct experience - which seems to indicate that (at least the more recently manufactured) materials are tolerant.

And neither will Tempest confirm it, I tried to get them to do that a while back. All they would say is we have no reports of pump failure due to ethanol. They were conducting material certification tests at the time but the program was cancelled, so I was told by a Tempest person later.

The situation regarding the mechanical pump needs to be known before accepting E10 as a successful alternative fuel, the pump materials may not like it. There is no way to be sure.

Why pump manufacturers will not say what the materials are is corporate legal arrogant stupidity. They do not have to endorse the materials for any fuel, just let the customer know what they are so he can make that decision.
 
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No, I am not!

I am looking at the vanguard squadron and their 15 plus years of operating
with a standard mechanical fuel pump and my concerns are none.

That would assume there is just one fuel pump, or that you have the same part # as the Vanguard squadron does.

Have you verified either/both?
 
And neither will Tempest confirm it, I tried to get them to do that a while back. All they would say is we have no reports of pump failure due to ethanol. They were conducting material certification tests at the time but the program was cancelled, so I was told by a Tempest person later.

The situation regarding the mechanical pump needs to be known before accepting E10 as a successful alternative fuel, the pump materials may not like it. There is no way to be sure.

Why pump manufacturers will not say what the materials are is corporate legal arrogant stupidity. They do not have to endorse the materials for any fuel, just let the customer know what they are so he can make that decision.

If your livelihood depended on revenue from these pumps, you would not tell the world what was in there either. Too many copiers ready to exploit, and they might retain liability for the "will fit" parts anyway.

In the certification process, the materials, and processes are required to be provided to the FAA. I remember a Conti lawsuit was lost (or settled) when a "will fit" connecting rod failed. FAA said that the rod was manufactured to the specifications, processes, materials, and heat treat of the originals, thus it was a design defect and Conti was still responsible. Now THAT is ridiculous!

One might get a FOIA request to obtain such information, but it sure seems like a lot of trouble, as there are other failure modes in other components that also need to be addressed.
 
A few hundred hours means nothing. You need to know and understand the chemical composition of the materials involved and their potential interactions. Also, Lycoming can't and won't change the materials used within their engines without going through some type of expensive certification process. Thus, it is possible that the materials used in your engine may be the same as those used over the past decades.

It is irresponsible to say it is OK to use something in your engine when it is unknown what the impact, if any, will be. I'll give you an example, some years back one of our South American members posted his experience running auto fuel with ethanol, as they were required to do. One of the issues they have is that their engine driven fuel pumps tend to have a limited life span. (I don't recall the length.) The solution was to keep an extra fuel pump in their hangars. That is not a solution and the thought of the pump going out while on a trip is not appealing.

The Vanguard squadron has quite a few more hours than "a few hundred". I'm not advocating one side or the other, so I'll thank you not to take me to task for it. I removed my engine driven fuel pump entirely, so I'm much more of an experimental heretic than those merely wanting to run E10. :D
 
The Vanguard squadron has quite a few more hours than "a few hundred". I'm not advocating one side or the other, so I'll thank you not to take me to task for it. I removed my engine driven fuel pump entirely, so I'm much more of an experimental heretic than those merely wanting to run E10. :D

Sorry, the tone of my reply was a bit negative, that was not my intention

Your setup is different than what is normal and the tone of the thread is, "All is good with ethanol, come on in, the water is fine".

You have obviously gone off the reservation with regard to your fuel system but most have not and to advocate thay ethanol will not harm a "stock" airplane is irresponsible.

A lot of people read these threads now and in the future and often the long term results are not posted back to them and highlighted. This applies to building advice as well. I'm sure we have all seen building tips that make us cringe and hope no one follows the example.

In the case of ethanol, there are too many unknowns to put out a blanket statement that all is good. Even more so to use the marketing team known as the Vanguard Squadron. I'm yet to see a list of all the mods they have done. Also, I highly doubt they are running carburetors, as many of us are.

Again, my apologies for coming across so harshly above.
 
FWIW, I had phone conversations several years ago with an engineer at Tempest, and while he didn't specify materials, he did tell me that all their current production fuel pumps are immune to alcohol degradation. The gist of the conversation was that current production basically uses what's in the automotive engine driven fuel pumps (yes, you can still buy them), and the automotive pumps have to stand up to E-whatever. They obviously won't put that on paper, because they haven't jumped through all the FAA-required hoops to change the fuel ratings on the pump. No real reason to, since FAA won't allow E-gas in type-cert a/c.

The same guy said also that there are no issues with E-gas in Marvel-Schebler carbs; even the antique that's on my O-320B2A (same parent company).

Again, FWIW. Anyone who's interested shouldn't take my word; they should ask for themselves. It's worthwhile to remember that hearsay is hearsay, no matter which position is being advocated.

I don't run E-gas yet for two reasons. First, my tanks were built in the early 1990's & I don't know what was used for sealant, and second, at the rate I fly, it would take years to pay back a fuel pump change (antique, non-E-proof pump).

But I have run E-free premium mogas for at least a decade with only one incident of rough running, due to my own stupidity: Old, winter blend mogas; plane sat on a blazing hot ramp (100F+ ambient temps) for hours followed by a takeoff during the hottest part of the day. I've had rough running issues with avgas in similar situations, so it's pretty hard for me to blame the mogas.

Charlie
 
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. . . Again, my apologies for coming across so harshly above.
Perhaps openly chastising posters and name calling are the culprit. Just a thought, but lecturing others tends to indeed come across as a bit negative.

Don't you think this post has a ring of negativity to it? ;) Just sayin'.
 
Re posted many times.

Here it is again
Default The Vanguard Squadron, 16 plus years of ethanol use
Gary Kuhns, lead pilot of the air show squadron, ?The Vanguards? has info on ethanol use. This is no surprise, they have been practicing and performing in RV-3s all the while running the IO-320 engines on ethanol and all mixtures of ethanol and avgas when flying x-country to and from the show sites. I figure with their 16+ years of ethanol experience, they can provide some insight for my own flex fuel project. In addition, by putting the team?s experiences out here on the board, hopefully it will answer a question that has come up occasionally on the vansairforce boards. What about the Vanguard Squadron? What have they done to the airplanes so they are ethanol compatible?

This posting is based on 3 or 4 conversations I had with Gary during 2010. The last conversation we had, Gary added some clarifications and corrections to the draft I had sent him.

Basics on the Vanguard airplanes
Four similar Rv-3 airplanes, N6GT, N16MR, N19EH, N25RV
IO-320 and wood Sensenich propellors

Fuel system
Like many other early Rv-3s, all four Vanguard airplanes have 24 gallon fuselage tanks. However, two of the four also sport wing tanks giving them impressive fuel capacity. None of the fuel tanks were built using special procedures or unusual materials as the planes were built with avgas in mind. Aerobatics are flown with wing tanks (if present) empty and fuel feeding from a flop tube inside the fuselage tanks. All have a factory type mechanical fuel pump and backup electric pump on the firewall. In order to accommodate the higher fuel flow needed with ethanol, Airflow Performance, Inc has re-calibrated the Bendix fuel injection systems. None of the airplanes have fuel drain sumps or gascolaters, Gary reports they were removed when they realized they weren?t performing any function. There is no separation of water and any particulates are trapped at the screened inlet to the Bendix fuel servo. All four have avgas priming systems for cold starts. They use a small fuel tank, (weed-wacker size) mounted behind the seat to feed the priming system.

I specifically asked Gary if they have had any fuel pump failures or tank sealing problems. He couldn?t recall any, and he asked the rest of the team if they experienced any issues. None. Gary did report Van?s Aircraft advised flop tubes needed inspected for softening/swelling. All four airplanes got the inspection and flop tubes were in good condition.

Engine setup.
All four airplanes now run high compression ratios. Three of the engines had engine work and the 10 to 1 setup by FWF/Demars approximately 20 years ago. Two of those engines are still in use. The third, N16MR got a new engine set up as 10.8 to 1 compression by Central Cylinder, Omaha NE. Gary?s N6GT was for many years just a stock 160 hp 320. The recent rebuild at Central Cylinder utilized the old crankshaft and case, though he reports the case got beefed up. Central Cylinder set his engine up with the custom pistons as well and he is running 10.8 to 1.

All four engines are have inverted oil systems.

Performance.
The team is very happy with the airplanes performance. Gary as formation lead, runs partial throttle throughout the routine, allowing the others to apply power as necessary for positioning. The team appreciates the consistency, smoothness, and reserve power that is available with these airplanes. Gary did not report any detailed performance testing, as they are very happy with how the planes performed, so they haven?t been in a troubleshooting or documentation mode. On Gary?s lead airplane, N6GT, he reported the rebuild shop saw 175 HP on their dyno running avgas. Gary?s estimate of HP while running on ethanol based on climb rates and speed is an additional 10 HP. (probably due to charge cooling, compare the latent heat of ethanol to gasoline, the ethanol is cooling the inlet stream- Stan).
Cold starting on ethanol is a problem. The engines like pre-heaters. The avgas priming system is used when below 50 degrees F. Once the engine is running, the avgas isn?t needed. Gary reported they had trouble finding fuel ethanol near one air show, so they used a local E-85 pump and had no trouble on starting. The 85% ethanol with the 15% gasoline likely provides enough easily vaporizing components for cold starting.
Gary reports no vapor lock issues, though he does caution they don?t have any significant experience at higher altitudes (over 10,000 feet). They don?t spend time up high.
Gary did report that back in 1993, he remembers a short clean out period when the engines were switched from avgas to ethanol. They observed some smoke in the exhaust as the ethanol loosened carbon up and the engine cleaned out.

Fuel composition
Ethanol, but when traveling back and forth to air shows, they will use 100LL as necessary, since that is what is available at fuel stops. Gary suspects they have run on about every possible combination of ethanol and avgas.

**The non-technical, keep it simple folks say, 100% ethanol, but pure ethanol doesn?t exist legally in the US motor fuel market, since gasoline presence is required by law so the liquor taxes continue to flow. The highest ethanol concentration you?ll legally see outside the production plant fence will still have 2 to 5 percent gasoline, and this is what the Vanguard squadron normally consumes, as do folks seeking ethanol out for racing. They find a plant or distributer who will sell the denatured ethanol (Stan?s comment).

Fuel flows
Gary reports approximately 15-20% more fuel flow on ethanol than avgas. The fuel injection system was set up for the higher fuel flow, so when running avgas, operations can easily be over-rich. The pilot compensates with the mixture control but it?s fairly close to the lean edge of the adjustment window. Tractability on avgas is OK if the pilot stays on top of it.
Some comparative fuel burns. Numbers come from the digital flow meter on Gary?s N6GT. Slightly rich of peak at 7500 to 8000 feet 140 to 145 knots, Gary sees about 9.3 gph on ethanol and 8.4-5 on av-gas. Gary?s leaning protocol (fixed pitch), lean until RPM loss, then go rich to gain back RPM, then a touch more rich. Gary observes 350 to 375 F CHT?s in cruise. He is in the cruise ROP camp, so if he observes CHTs approaching 400 F, he adds fuel.

Warning on carbs. Gary reported a carburated engine operator running on ethanol had a fuel stoppage. The operator told him of occasional fuel interruptions as the airplane warmed up (about 20 minutes into operations). The problem was traced to inlet valve seat. Apparently, the fiber seat would swell and cut off fuel flow. The operator reported the seat was replaced with brass and the problem was fixed.

Lastly, I will mention that Poet (previously known as Broin) sponsors the squadron, and if you?ve seen the airplanes or been to their website ethanolairshows.com you?ll already know this. So, the airplanes fly largely because a well known and successful ethanol company has chosen to support their efforts. What that means I don?t know for sure, but given the anti-ethanol aviation landscape, the corporate support is likely the one thing that allowed the ?test? to occur. Who else would have done such a thing? In talking with Gary, it seems pretty simple. I get the sense that they'd been doing this for so long and it has worked so well, that running on ethanol is a non-issue. Interesting, considering all the predictions that have been made on what will happen to gaskets, fuel lines, fuel pumps, and etc.
__________________
Stan
1990 RV-3 (now apart, upgrades in the works)
1959 C172 O-360
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If you look at the Petersen Auto Gas STC site, there is good info there about using car gas in planes, and with tens of thousands of STC's for certified planes. I would think they know a little about car gas.

The main problem with ethanol in fuel it its ability to attract water from the air, and when conditions are right, the water separates from the fuel and then you get to run a quantity of water thru your carb, or injectors. Unless you have a real special engine that runs on water, this can be an exciting time I would think.

I have flown probably 500 hours with car gas in a Cherokee, and RV6A, and have heeded the good advice to use gas that is all gas and not gas with corn squeezins mixed in, and it has always worked super for me.

You used to be able to get 87 octane that was pure gas, but its hard if not impossible to find now. Super unleaded is often pure gas, and if you ask the dealer they should even have a data sheet on their gas which gives the specs.
 
I have flown probably 500 hours with car gas in a Cherokee, and RV6A, and have heeded the good advice to use gas that is all gas and not gas with corn squeezins mixed in, and it has always worked super for me.

Once again, someone who has not tried ethanol and knows all about how
"it doesn't work".

I understand how the Peterson STC people feel after their STCs no longer apply when used in conjunction with E10.
It would not be in their best interest to imply that 91 Octane E10 works just as well as pure gasoline.

The solution was to keep an extra fuel pump in their hangars. That is not a solution and the thought of the pump going out while on a trip is not appealing.

You are right that is not the solution.
However, a brand new Tempest fuel pump can be bought for less than 300 hundred dollars, not really a big ticket item to keep in stock.
Or you could just trust all that has been said about the use of alcohol tolerant rubber now being used in Lycoming fuel Pumps. You could also just look at all the people using E10 and mechanical pumps and not have any problems especially the Vanguard squadrons 15 plus years of ethanol use.
Still worried? 2 electric fuel pumps can solve the issue as well.

It is irresponsible to say it is OK to use something in your engine when it is unknown what the impact

Let me be very clear about what I am saying here:
I am telling this forum that 91 Octane E10 works very well for me, what you do with the information is up to you.

A lot of people read these threads now and in the future and often the long term results are not posted back to them and highlighted

I think 15 years of running ethanol in RVs without adverse effects is
certainly long term enough for me not to worry about effects and unknowns.

I am hoping that more of you will read the success stories and summon the courage to try something that others have done very successfully with thousands of hours of testing and make use of your experimental privilege rather than withdrawing to the confines of the certified world.
 
If you look at the Petersen Auto Gas STC site, there is good info there about using car gas in planes, and with tens of thousands of STC's for certified planes. I would think they know a little about car gas.

The main problem with ethanol in fuel it its ability to attract water from the air, and when conditions are right, the water separates from the fuel and then you get to run a quantity of water thru your carb, or injectors. Unless you have a real special engine that runs on water, this can be an exciting time I would think.

I have flown probably 500 hours with car gas in a Cherokee, and RV6A, and have heeded the good advice to use gas that is all gas and not gas with corn squeezins mixed in, and it has always worked super for me.

You used to be able to get 87 octane that was pure gas, but its hard if not impossible to find now. Super unleaded is often pure gas, and if you ask the dealer they should even have a data sheet on their gas which gives the specs.

The Peterson & EAA STC's are FAA documents; FAA won't allow E-gas, so they say that it isn't ok for the type cert a/c using them. Might mean it's dangerous, or it might be because *some* STC'd a/c *might* fly far up in the O2 levels where E could be a problem. Or it might just be the FAA...

Since the problem with E is its ability to attract water from the air, does it not logically follow that checking avgas-only tanks for water is unnecessary?
E will simply draw the water present in the gas into solution with itself, where it would be drained off. Like water. Biggest downside is reduced octane rating when the E leaves with the water. Water vapor will condense anywhere there's a nice cool surface in the presence of high, warm humidity. The same condensation process happens in a tank of avgas. (Coming to you from Mississippi, home of sweet ice tea, 95 degree temps and 110% humidity.)

If finding 'pure' gas is a problem in Far North TX, perhaps you should move to a more progressive state, like Mississippi....where all three grades are widely available E-free. :) It's actually harder (but not that difficult) to find premium E-free than 87 here.

Lots of alt engine guys run E-gas in the same tanks/sealants/fuel lines that have come stock in RV's for over a decade, so the airframe isn't an issue (not the same for many fiberglass tanks). The only alt engine guy I know who went back to avgas did so because he was fueling from plastic cans & had a static ignition. Would have happened with avgas from a plastic can, too, but avgas typically comes from a grounded hose. Which is why he went back to avgas.

Charlie
 
Almost 700 hrs on Mogas E-10

Haven't been visiting much lately but thought some of you might like to know that my fuel system has served me well and I still run on 91-E10 mogas.
Going on 10 years now, without a single fuel related issue.
Just reporting, not trying to convince anyone.
 
Haven't been visiting much lately but thought some of you might like to know that my fuel system has served me well and I still run on 91-E10 mogas.
Going on 10 years now, without a single fuel related issue.
Just reporting, not trying to convince anyone.

Same here, just over 4 years and almost 700 hours on Walmart-grade 91E10.
 
I have 500 hours on my RV-12 Rotax 912ULS using 93E10. I buy tier-one fuel at Costco. Rotax is designed to use high octane auto fuel with up alcohol.
 
These latest posts are very encouraging. We have a non-certified engine. All fuel lines are alcohol compatible as is the CS3204 Flamemaster sealant used in the tanks.

Our plan is to burn 93E10, unless on a x-country where only 100LL is available.

Add in the state rebate for sales tax, and it's a no brainer.

Years ago we burned 89 Octane mogas in our 172. Many trouble free hours. In fact, the Lycoming ran much better on the UL gas.

Here is a more recent thread on the subject: http://www.vansairforce.com/community/showthread.php?t=174063&highlight=Mogas+100LL
 
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