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View Full Version : Are there any Continental o-200 configurations that make ethanol OK?



DavidDeutsch
08-27-2012, 01:22 PM
Hello,

I've read somewhere (though I cannot find it now) that if a Continental has certain types of "things" (seals, o-rings, carburetor, etc) that you can use E10 in it, at least part of the time. Does anyone know what these "things" are? Being able to use gas from a local station would go a long way towards reducing the hourly cost of flying.

FlyingRon
08-27-2012, 02:08 PM
There is no legal way to put ethanol of any sort into a certificated aircraft operating under the EAA or Petersen STCs.

As far as experimentals goes, that is up to you. Not only do you need to look at the carb but also the rest of the fuel system (notably the gascolator is known to be a problem with it's o-rings swelling) as well as corrosion issues in the tank and any metal lines you have. Then you get to play aircraft engineer and test pilot with regard to volatility and vapor lock (of course, you did that as soon as you put autogas in the thing anyhow).

Jim Heffelfinger
08-27-2012, 05:17 PM
Dave,
I am going to assume that you mean '...configurations that allow ethanol' . The next question - how much are you talking about ? I am assuming it is the mogas 10% and I am going to shift toward the end of the branch and say most engines will tolerate 10% ethanol - but as noted before - many of the seals, rubbers, plastics that have fuel either running through them or potentially splashed/dripped on will need to be checked for compatibility.
A certified engine running on non certified fuel takes the engine out of certification. A certified engine/prop running on non certified fuel during Phase One flight will void your 25 hours and move you into the more common 40 hours of Phase One.
As noted - once out of certification you are now experimental. The next question from me is.... once out of certification can it be brought back into certification?

nrpetersen
08-27-2012, 06:35 PM
A hangarmate w a Cessna 140A had his fuel line swell partially shut from FBO sourced fuel. It turned out they accidently got a load of E10 rather than the UL they had requested & didn't test it since it was a "certified load". The bulk truck guy grabbed the wrong hose. I figured from my tests that his airplane had about 5% ethanol.

mmorrison123
08-29-2012, 07:39 PM
On the subject of ethanol, does anyone have an actual first hand story about ethanol causing a serious problem with their (experimental) airplane. I have read lots of warnings about what it could/will do, but these all seem to be the same warning that is just passed along. We are all scared of ethanol, I am too, but I would love to know if there are some real, no doubt, 100% sure cases of ethanol problems in aircraft engines. Just asking!

rosiejerryrosie
08-30-2012, 07:07 AM
MMorrison123, Yep. I know of two actual cases that I have seen personally. The first was a friend's Kolb that the ethanol "digested" the fuel tank and leaked 10 gallons of ethanol tainted fuel on to his hangar floor. The other was a friend in a Phantom who made an off airport landing when the engine quit. Investigation showed the gascolator plugged with some "sludge" looking material. Backtracking through the fuel system showed the inside of the fuel tank flaking off with about a 1/4 inch of residue in the bottom of the tank. It had deteriorated to the extent that in areas of the tank, one could poke your finger through the tank with little effort. In my lawn mower, it has required two costly trips to the maintenance facility to have the fuel system flushed out and all gaskets and filters replaced. The owner of the shop said that his business has doubled since the introduction of ethanol in gasoline. That, plus what it has done toward raising the price of corn, corn products and all meat raised on corn (beef, chicken, pork, eggs, etc), is enough for me to hate the stuff!

cub builder
08-30-2012, 05:03 PM
I've seen two cases in certificated aircraft where the owner unknowingly used ethanol tainted mogas. Both caused significant damage to the glass tanks. In one case, the tip tanks on a Cherokee 235 were so soft they were deforming in flight. In the other case, the inlet screen on the carb was plugged up with brown sludge that appeared to be glass resin from the fuel tank causing the engine to quit in flight. Plane ended up on it's back in a field.

-CubBuilder

mmorrison123
08-30-2012, 06:19 PM
So it seems that the issue is with certain types of fuel tanks? I flew a Kolb for a couple years, about 100 hours. It came with a plastic fuel tank and I never had a problem with ethanol. Same with the Titan Tornado that I fly now. The plastic fuel cans that I use to store/transport fuel for my airplanes, mowers, etc seem unaffected, as do the fuel tanks in my cars. I built a fiberglass fuel tank for my Pietenpol Aircamper using vinylester resin as it was claimed to hold up to ethanol, but I have not tried it yet. I know that the boat people have been having issues with epoxy and polyester resin fuel tanks. Do you guys know what type of resin was used to construct the Cherokee tanks, or what the Kolb tank was made of? I agree that we should be eating corn, not trying to run our engines on it, but is the safety simply a matter of using it in plastic, vinylester, or metal fuel tanks?

kmisegades@bellsouth.net
08-30-2012, 06:53 PM
Why would anyone want to take the risks using ethanol-blended fuels? Even if you could make your entire fuel system ethanol-proof, you will lose power and range since ethanol has only 70% of the BTUs per gallon of gasoline.

Better is to support the airports selling mogas, which you can find on this list and map:
http://www.flyunleaded.com/airports.php
http://www.flyunleaded.com/mapusairports.html

Find ethanol-free at other retail locations here:
http://pure-gas.org/

Rod Hightower stated in an intervew during AirVenture 2012 that having mogas at Oshkosh is his #1 priority for improvements in 2013. Why not follow his lead and do the same for your airport? Join the free Aviation Fuel Club to learn more and help others, www.aviationfuelclub.org

mmorrison123
08-30-2012, 08:18 PM
It's the risk that I'm trying to determine. What is the real risk of using ethanol blended fuel in my airplane? I know it's less powerful (10% ethanol * 70% power + 90% gas * 100% power means ethanol blend has only 97% of the power of no-ethanol fuel). The list of ethanol free fuel suppliers is great, but the closest is a 3 hour round trip from me. Avgas costs about $2.25 more per gallon than local mogas. Not a show stopper, but if I can save $10 per hour operating costs, without ruining my engine or plummeting to my death I would like to do that. I have about 180 hours on Rotax 503's running local mogas with no problems that I can attribute to ethanol. Do you have any figures on the costs of ethanol free fuel from those airports or other suppliers that have it? Airports where I have been able to buy ethanol free fuel have charged almost as much as avgas.

FlyingRon
08-31-2012, 04:21 AM
The problem isn't so much the energy density as the fact that ethanol has some nasty reactive propeties part of which is because it's hydroscopic and part is that fuel systems weren't designed to encounter it. This has been a big concern in the boating industry where WATER is a more invasive problem. The sad truth is aviation fuel tends to sit in tanks a lot (avgas is specifically stabilized) which car gas is not and it gives the ethanol time to attack the tanks, etc...

kmisegades@bellsouth.net
08-31-2012, 05:51 AM
It's the risk that I'm trying to determine. What is the real risk of using ethanol blended fuel in my airplane? I know it's less powerful (10% ethanol * 70% power + 90% gas * 100% power means ethanol blend has only 97% of the power of no-ethanol fuel). The list of ethanol free fuel suppliers is great, but the closest is a 3 hour round trip from me. Avgas costs about $2.25 more per gallon than local mogas. Not a show stopper, but if I can save $10 per hour operating costs, without ruining my engine or plummeting to my death I would like to do that. I have about 180 hours on Rotax 503's running local mogas with no problems that I can attribute to ethanol. Do you have any figures on the costs of ethanol free fuel from those airports or other suppliers that have it? Airports where I have been able to buy ethanol free fuel have charged almost as much as avgas.

Using ethanol in any engine AND airframe combination that has not been designed for it, TC'd or STC'd is not only illegal but it is the equivalent of playing Russian roulette. An Experimental category aircraft can burn any fuel, otherwise it is not legal to use and ethanol blend unless it is approved and listed in the engine/airfram TC and/or STC. The effects of ethanol are cumulative, and all it takes is one batch to start the deterioration of incompatible parts. Even if all your materials can handle E10, how do you know that the fuel you are buying is not in fact E15 or even E30 ? There have been plenty of documented cases of gas stations selling much higher levels of ethanol than permitted, and no state does testing - it is simply left up to the buyer to beware.

You will find mogas prices at airport in AirNav's statistics:
http://www.airnav.com/fuel/report.html

Mogas is selling, on average, for $1.50 less than Avgas. When you buy it at an airport, you can be assured that it is aviation-grade, the best being 91+ AKI, ethanol and lead free, low RVP vapor pressure, filtered in aviation grade filters. Anything you buy at a gas station is a risk, so make sure you check every batch for ethanol even if it is listed as being ethanol-free. Buy from branded dealers and try getting the highest AKI rating, 93 is best, since generally the higher the AKI the better the fuel quality.

Even if you could make an O-200's many parts (especially the carburetor) compatible with E10, when the fuel sits in the tanks or carb bowl for a week or more, the ethanol in the fuel is absorbing water from the atmosphere. Eventually you will have phase separation, and now that water/ethanol mixture will begin to eat its way into all the materials it touches. It is a highly-corrosive chemical that has been known to eat right into composites and elastomers, causing them to swell or turn into a stick goo that will eventually find its way into your engine. If you are lucky, it will happen before your reach an altitude when they subsequent engine failure or fuel fire will kill you.

The solution is simple - work with your local airport to bring high-quality mogas directly from the fuel terminal to your airport. Trucks delivering fuel to your local gas stations probably drive near your airport weekly. All terminals have ethanol-free fuel since that is where the ethanol is added to the ethanol-free that comes out of a gasoline pipeline. When you use fuel from a gas station, you are paying highway fuel taxes - that does not help our airports. When you buy it at an airport you are paying into the aviation funds and they need every penny these days.

kmisegades@bellsouth.net
08-31-2012, 06:03 AM
The problem isn't so much the energy density as the fact that ethanol has some nasty reactive propeties part of which is because it's hydroscopic and part is that fuel systems weren't designed to encounter it. This has been a big concern in the boating industry where WATER is a more invasive problem. The sad truth is aviation fuel tends to sit in tanks a lot (avgas is specifically stabilized) which car gas is not and it gives the ethanol time to attack the tanks, etc...

This is not entirely accurate. Water is a problem for boats and aircraft due to the open-vented fuel systems used, not because they are operated near water. Modern cars, by contrast, used closed, pressurized fuel systems so there is less water absorbed from the atmosphere. Statistically, private boats and airplanes are operated about the same annually, around 50 hours, the rest of the time they sit in a hangar, shed, etc. If fuel remains in the system, and it contains ethanol, it will eventually reach saturation and phase separation occurs. The resulting ethanol/water mixture sinks to the bottom of fuel tanks, lines, pumps, carbs, etc. and starts eating into the surrounding surfaces.

Quality gasoline without ethanol (aka Mogas) has a stable shelf-life of about one year. Avgas shelf life is 1-2 years. Put ethanol in gasoline, or in 100LL for that matter, and the shelf life drops to a few weeks.

mmorrison123
08-31-2012, 07:04 AM
Great info guys. I'm just trying to fully understand the issues. All I have to go by is my personal experience and what I can find in the media. My 180 hours flying in the past 4 years comes very close to the 50 hour per year that was mentioned as an average for airplanes. 95% of that was using car gas with ethanol (10 or more percent, I'm not sure). I use the same fuel in my mowers, snowblower, power washer, and weedeaters, all of which have open-vented fuel systems. I never drain the tanks or use Stabil during the off seasons. And I'm not aware of a single issue that I'm experiencing due to ethanol phase separation or damage to fuel system components. Again, I'm not saying that it isn't occurring, just that if it is, I can't see any indication.

I think that the simple solution of getting mogas delivered to all our local airports might be a little more difficult than stated. Wouldn't the airport need some type of approved fuel tank and delivery system, separate and in addition to what they already have for avgas. I know when one local airport installed such a system for avgas it was very expensive. Since I'm the only one at my airport using mogas I doubt I could talk the owners into investing in this.

Again, this is all great info about what ethanol could do, but is this really what ethanol does? So far we have a Cessna, Kolb, and Phantom with fuel tanks made from unknown resin (was it epoxy, polyester, vinylester) that experienced terrible, sometimes immediate deterioration due to ethanol. What is different about their situation than mine, and are there others out there that are using ethanol blend with no apparent problems? Once again, just trying to educate myself.

lapanceri
09-02-2012, 05:53 PM
I sugest You to check Brazilian experience about fuel with ethanol. There are a experience greater than 30 years whit
mixing up to 25% ethanol in the auto gas and many pilots flying with experimental airplanes whit this fuel whitout problems.
In some situations, a lot of ag pilots flying their agricultural airplanes (certified) with pure ethanol. I personaly test all
parts of my fuel thank (using litle parts of it) submersed in pure ethanol for more than 6 years without signs of corrosion,
included in this test a rubber fuel pump diaphragm. I flow with pure ethanol arround 200 hours in a experimental airplane
equiped with VW engine witout problems. My unique prevention is a separate fuel tank with avgas for start and stop
engine, it means that fly intervals, all the fuel sistem rest with avgas.

kmisegades@bellsouth.net
09-03-2012, 06:29 AM
Great info guys. I'm just trying to fully understand the issues. All I have to go by is my personal experience and what I can find in the media. My 180 hours flying in the past 4 years comes very close to the 50 hour per year that was mentioned as an average for airplanes. 95% of that was using car gas with ethanol (10 or more percent, I'm not sure). I use the same fuel in my mowers, snowblower, power washer, and weedeaters, all of which have open-vented fuel systems. I never drain the tanks or use Stabil during the off seasons. And I'm not aware of a single issue that I'm experiencing due to ethanol phase separation or damage to fuel system components. Again, I'm not saying that it isn't occurring, just that if it is, I can't see any indication.

I think that the simple solution of getting mogas delivered to all our local airports might be a little more difficult than stated. Wouldn't the airport need some type of approved fuel tank and delivery system, separate and in addition to what they already have for avgas. I know when one local airport installed such a system for avgas it was very expensive. Since I'm the only one at my airport using mogas I doubt I could talk the owners into investing in this.

Again, this is all great info about what ethanol could do, but is this really what ethanol does? So far we have a Cessna, Kolb, and Phantom with fuel tanks made from unknown resin (was it epoxy, polyester, vinylester) that experienced terrible, sometimes immediate deterioration due to ethanol. What is different about their situation than mine, and are there others out there that are using ethanol blend with no apparent problems? Once again, just trying to educate myself.

Your experience is quite the exception. Read the thousands of comments on this petition to the EPA, asking that premium fuel be excluded from ethanol blending. Many document costly damage to their engines, including the complete loss of aircraft. http://pure-gas.org/petition

Fuel equipment does not have to cost $100,000 or more. There are plenty of good, surplus military aviation fuel trailers available for pennies on the dollar. If airports want pilots to continue flying, they will eventually see that mogas is the only way to significantly reduce the cost of flying. When avgas disappears as it has in most places outside the US and Europe, the only fuel will be mogas, but without ethanol.

kmisegades@bellsouth.net
09-03-2012, 06:35 AM
Brazil is another story altogether. It has cheap ethanol which is a great incentive to go through all the trouble of making it work in aircraft. Experimental aircraft can burn anything, but this does not eliminate the problems ethanol blends cause. I understand that in Brazil the Ipanema crop duster and a special Lycoming engine have been certified to run on 100% ethanol. When however the owner of the plane produces ethanol from the sugar cane the crop duster sprays, it is obviously more economical to try using the fuel. But I doubt that many pilots in the US would want the trouble of having to drain the fuel tanks and fuel system any time the plane is not being operated. The Brazilian company Aeroalcool tested a number of engines running on 100% ethanol and developed Brazilian STCs for them. I understand that Aeroalcool could not make a business from this as Brazilian pilots burn ethanol despite not paying the money to Aeroalcool for the STC. Do that in the U.S. and you face serious consequences from the FAA and your insurance company when something goes wrong. Eliminate the government subsidies and mandates for ethanol in Brazil and the biofuels industry will likely collapse as it is in the U.S. now. I would not want to invest in any technology for an airplane based on a fuel that only exists as a result of a government program.

cub builder
09-04-2012, 09:59 AM
Again, this is all great info about what ethanol could do, but is this really what ethanol does? So far we have a Cessna, Kolb, and Phantom with fuel tanks made from unknown resin (was it epoxy, polyester, vinylester) that experienced terrible, sometimes immediate deterioration due to ethanol. What is different about their situation than mine, and are there others out there that are using ethanol blend with no apparent problems? Once again, just trying to educate myself.

So far, I have observed damaged tanks with Vinylester, Polyester, and Epoxy resins. Most alcohol "resistant" slosh compounds will protect the resins and tolerate some exposure, but won't stand up to long term exposure. Many of the MS carbs have composite floats in them that also may not tolerate ethanol. As far as we know, it won't damage an O-200 to run on alcohol contaminated fuel or anything else that burns as long as it can avoid detonation. However, for the long term, you need to eliminate most plastics, rubber, neoprene, cork, composite resins, and aluminum from your fuel systems, and then run a closed fuel system (as opposed to an open vented fuel system) to avoid drawing water while in storage. If you can do all that and don't mind carrying the weight associated with that type of fuel system, then your O-200 will probably be happy to burn the fuel. But, as a practical matter, 100LL and Ethanol Free gasolines are a much more practical solution.

-CubBuilder

mmorrison123
09-04-2012, 09:19 PM
Thanks for the link to the pure-gas.org petition. I spent some time looking at the comments from my home PA. I even recognized a few of the names, but believe it or not, I'm still skeptical. A vast majority of the hundreds of comments seemed to echo what ethanol could do, or state why they desired pure gas, or state that ethanol was just plain a bad idea. There were some comments that spoke of costly repair bills and destroyed engines, but I just haven't had the same experience, nor has anyone else that I know. Our lawn mowers, cars, power washers, snow blowers, and ultralights are all still running. Perhaps they are not running as well as they used to but I can't tell. Maybe my gas mileage is down, I'm not sure, but it's not down 40% as some in the petition are claiming. I don't think that my experience is the exception at all. As far as the vinylester fuel tank that was damaged by ethanol, I would really like to learn more. Many of us homebuilders have hung our hat on the supposed fact that vinylester will hold up to ethanol. If this is not true it is very important. As for the fuel truck/trailer, that's what one local airport used to use, but some govt organization, I'm not sure if it was the EPA,FAA,DOT or whom, told them it they had to but in a permanent approved (expensive) tank.

cub builder
09-05-2012, 07:44 AM
Many of us homebuilders have hung our hat on the supposed fact that vinylester will hold up to ethanol. If this is not true it is very important.

Go visit KRNet.org. A very meticulous builder hung his hat on vinylester being impervious to alcohol. He never even got in his first flight before he had a gascolator full of brown goo followed a couple of weeks later by fuel seeps from the tanks. Now his plane is down while he builds aluminum tanks.

Some of the spun polyethylene tanks such as those found in some lawn mowers and weed eaters do indeed seem to tolerate ethanol. That has been my experience as well. The question is, do you want to find our what does and doesn't work while you're in the air?

You've asked for anecdotal evidence that there are problems with ethanol. Folks here have shared their knowledge and experience with you. You choose not to believe them. So why did you ask?

-CubBuilder

Tom Downey
09-05-2012, 09:54 AM
When we were handling parts of the ADI systems on both the G-1, (TC4C) and the Super Connie we always had to keep the parts submersed in ADI fluid to stop the corrosion, if you removed the parts and let them dry, they would corrode over night.

ADI fluid is Alcohol and Water mixed to engine manufacturers requirements.

mmorrison123
09-05-2012, 11:35 AM
CubBuilder

You are absolutely correct that I asked for anecdotal evidence about the problems with ethanol in aircraft. I'm sorry if I have offended anyone by questioning their findings. My intent was simple to see what problems people have been experiencing. Most of the information that I have seen outside of this thread is from people relating stories about others. Those that believe they are having ethanol issues seem very certain, but I still wonder if their individual problems could be caused by something else. I'm certainly guilty of misdiagnosing problems. Who knows, maybe I too am experiencing ethanol issues, or am about to. I'm just trying to make sense of the wide range of issues that we are experiencing, from total failure of fuel systems, to major loss of power and performance, to no apparent effect at all. Thanks for the info about the KR tank. That has me worried about my vinylester tank in the Pietenpol that I'm building. It seems that aluminum would be no better as far as ethanol is concerned.

Just Another Pilot
10-07-2012, 08:27 AM
Mmorrison123,

Good question on the EAA forum. Too bad others are quickto judge. I think the debate has only begun.

Some factors to consider in the use of any fuel are decomposition,corrosion, economics, environmental, operational and safety advantages or disadvantages.As far as ethanol is concerned the disadvantages can be overcome. As far as advantages,there are many.

Two considerations:- While an aircraft operates; what willethanol do while it runs through the veins (fuel system) and in the heartitself (the engine)? And while an aircraft is not operational (sits for hours,days, weeks, months); what does ethanol do to the structure as well to itself.

When 100LL disappears or becomes so expensive it willsubstantially ground the current certified general small aircraft fleet and wewill have to turn to either mogas or ethanol. From where I sit, I believeethanol is a viable alternate given the choices.

Mogas by the nature of its manufacture and blend is notsuitable for many aircraft operations. Simply removing ethanol from mogas willnot solve the problems of vapour lock and engine lock. In my opinion theseissues are deal breakers. The only ‘gasoline’ option is creating a new avgas. Iwould hate to see what that will cost.

REAL Ethanol (E85 or purer) on the other hand will causedamage to certain components. So it’s a few components we need to consider modifyingor changing, not the fuel. Seems like a lot simpler solution to me.

Just my humble opinion.

Kurt Flunkn
10-07-2012, 05:44 PM
Hi David,

Focusing on the question "Are there any Continental o-200 configurations that make ethanol OK" A quick review of the Regulation Guidance Library (at www.faa.gov (http://www.faa.gov)) limited to the Type Certificate Data Sheets (TCDS) and Supplemental Type Certificates (STC) for the 0-200A, B, C, D, and X show that 1). only avgas is approved as fuels and 2). there are no STC for ethanol. The EAA's STCs only allow "unleaded automotive gasoline, 87 minimum antiknock index, per ASTM Specification D-439 or D-4818 of any volatility class, A through E, or 82UL AVGAS per ASTM D-6227."

So the short answer is "no" for certificated aircraft and of course this does not apply to experimental aircraft.

FlyingRon
10-11-2012, 06:04 AM
Thanks for the Reiteration, Kurt. It's pretty much what I said in the very first reply.

Bob Dingley
10-13-2012, 10:37 AM
FlyingRon answered the question in the first reply to this thread. He cited the EAA and Petersen STCs that totaly bar any ethanol use whatsoever. Using ethanol implies that your'e using Auto Gas and that brings up more questions. I haven't seen the EAA STC. Todd Petersen also has done a bunch of testing and published a bunch of info on his web site.

http://www.autofuelstc.com/autofuelstc/pa/Home.html

I find that 30 minutes on his site is a mini course on aviation fuel and answers the questions that you asked.
Petersen lists lots of O-200 models approved for STC. He discusses valve seat recession as a problem with small TCM engines among many others. He says that a tank of 100LL every 75 hours should fix it.

I was locked into 100LL on my last plane because when Petersen tested my type, it quit cold. He just moved on to the next one. I bought a new Dodge truck in 05 and it got 20 mpg on non ethanol fuel. When e-10 became prevelent, it dropped to around 15 mpg despite an aftermarket air filter, synthetic oil, tune ups and a presidentialy approved tire guage. I know that pure ethanol only has 70% of the energy of gasoline and reduces range in both aircraft and p.u. trucks by that much. I have a standby generator that is now inop because I gassed it up when the first hurricane came into the gulf.

I use the pure-gas.org web site and avoid e-10 whenever possible. I regard buying e-10 the same as buying a gallon of milk for the kids and finding that it is 10% dilluted with water.

Bob