Gami gas has arrived...

Katamarino said:
I'm counting on converting to a Deltahawk and burning Jet-A.
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That's one! A couple hundred thousand more and there might be a viable market. I'd be looking forward to being number 2 but I suspect by time it is real, I'll be dead.
 
So.... unleaded aviation fuel development and availability seems to be with battery aircraft / electric motors, flying cars, etc. It seems that it's also "Just around the corner".
 
JOhnH said:
That's one! A couple hundred thousand more and there might be a viable market. I'd be looking forward to being number 2 but I suspect by time it is real, I'll be dead.
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Hopefully not long now - the STC is under development. The RV14 install kit is nearly done, so they're learning rapidly.
 
Chrisgoesflying said:
I received this email from Piper on April 1st. Assuming it’s not an April’s fools prank, does it essentially say “don’t use anything else than 100LL in your Piper even if you have an STC for an alternative fuel.” ?

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Looks like corporate butt-covering. I especially liked
The use of any unapproved fuel in a Piper airplane will result in limited customer/​
technical support and will void the warranty for the fuel system and airframe structures associated with the fuel​
system and engine.​

Just how much customer support and warranty do they provide for a 1965 Cherokee (like many of us fly) anyway?
 
pfarber said:
The only real answer is 100% ethanol. The FAA ran a 13 year test running 100% ethanol on two AC and absolutely nothing bad happened.

Cheap, clean and works great. The FAA certified 100% ethanol for O-235 and O-540 engines back in the mid 1990's.

The only reason there is a hold up on unleaded gas is SPECIAL INTEREST MONEY.


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An aircraft did not have ethanol in it for 13 years. The study was 13 years. The test appears to be 13 months.

Ethanol loves water. It also hates aluminum.

Valve seat recession, extreme lean, and prop overspeed even after multiple repitches.

Yeah, its special interest money holding ethanol back.
 
Racerx said:
An aircraft did not have ethanol in it for 13 years. The study was 13 years. The test appears to be 13 months.

Ethanol loves water. It also hates aluminum.

Valve seat recession, extreme lean, and prop overspeed even after multiple repitches.

Yeah, its special interest money holding ethanol back.
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The deficiencies you noted were corrected and did not cause significant issues after they were corrected. so it's not that the ethanol was causing the problems it's just that ethanol is not a drop in replacement for avgas. that is a huge difference.

The ethanol loves water? what about diesel and jet fuel? they also love the water and could get nasty if sitting for a long time.

bottom line is with simple rejeting and a proper propeller pitch solved all of the " deficiencies " you thought were a problem. I also like how you forgot to mention the benefits of ethanol, like no detonation and lower price and the fact that the engine was so clean that it looked almost new after the test was done during tear down.
 
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also if you read the first citation it clearly states that an STC was granted in July of 1996, and one of the final paragraphs of the paper stated that the Cessna 152 had been continuously flying in Baylor's flight school since the STC was granted.

I find it hilarious that the FAA has already granted an STC for ethanol fuel based aircraft way back in 1996 yet GAMI is still futzing around with all these potions trying to make a buck off of a problem that's already been solved.
 
pfarber said:
The ethanol loves water? what about diesel and jet fuel? they also love the water and could get nasty if sitting for a long time.
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Unlike in gasoline where it collects in the sump where it can be drained out, water dissolves into ethanol, then it can come back out of solution if the temperature drops.
pfarber said:
bottom line is with simple rejeting and a proper propeller pitch solved all of the " deficiencies " you thought were a problem.
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Rejetting won't solve the energy density problem, which would significantly reduce the aircraft's range on ethanol compared to gasoline.

Racerx said:
Yeah, its special interest money holding ethanol back.
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It's special interest money (the farm lobby) promoting ethanol.
 
pfarber said:
bottom line is with simple rejeting and a proper propeller pitch solved all of the " deficiencies " you thought were a problem. I also like how you forgot to mention the benefits of ethanol, like no detonation and lower price and the fact that the engine was so clean that it looked almost new after the test was done during tear down.
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I'm guessing that if 100% Ethanol is the panacea you suggest it is, it would be in wide spread use. But it isn't ...
 
Dana said:
Unlike in gasoline where it collects in the sump where it can be drained out, water dissolves into ethanol, then it can come back out of solution if the temperature drops.

Rejetting won't solve the energy density problem, which would significantly reduce the aircraft's range on ethanol compared to gasoline.



It's special interest money (the farm lobby) promoting ethanol.
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The amount of water ethanol can hold it not significant in normal use. Ethanol holds, water, but it doesn't 'suck it out of the air'. Fuel tank condensation is a problem for all fuels. My 2014 Dodge is an E85 multifuel vehicle. I run E85 all the time. Its great for the engine. Other than a reduction in MPG due to less energy, E85 is a non issue.

So for all of the 'evils' you claim that pure ethanol would cause, why are they not an issue for E85? The best you could commercially get is 90-95% ethanol... why do you think that there is a huge difference between E85 and 'pure' ethanol?

The energy density of ethanol is a know factor. Would you rather pay $7-$8 a gallon for 100UL or $4 for ethanol? Would you like to say goodbye to fouled plugs? How about oil changes that last more than 25-50 hours? In the Baylor ethanol test the fuel consumption went from 12GPH to 15GPH. So some math: for a 50 Gallon fuel load your range went from 4.1hrs to 3.3hrs. 50 Gallons of 100UL is (50*$8) $350 vs (50*4) $200. But since you had to burn more ethanol (.8 * 15) 12 gallons that's an extra (12* 4) $48. So your total fuel bill is $248 vs $350. Saving $102 per tank. Is that really a downside? A cleaner engine, more power (faster cruise) and about 30% less fuel cost?

Ethanol is already a viable fuel. Has been for decades. There are no downsides that will magically appear. Also I would rather US farmers get my money than places like Venezuela, Russia, Saudi Arabia, Kuwait etc etc.
 
pfarber said:
The amount of water ethanol can hold it not significant in normal use. Ethanol holds, water, but it doesn't 'suck it out of the air'. Fuel tank condensation is a problem for all fuels. My 2014 Dodge is an E85 multifuel vehicle. I run E85 all the time. Its great for the engine. Other than a reduction in MPG due to less energy, E85 is a non issue.

So for all of the 'evils' you claim that pure ethanol would cause, why are they not an issue for E85? The best you could commercially get is 90-95% ethanol... why do you think that there is a huge difference between E85 and 'pure' ethanol?

The energy density of ethanol is a know factor. Would you rather pay $7-$8 a gallon for 100UL or $4 for ethanol? Would you like to say goodbye to fouled plugs? How about oil changes that last more than 25-50 hours? In the Baylor ethanol test the fuel consumption went from 12GPH to 15GPH. So some math: for a 50 Gallon fuel load your range went from 4.1hrs to 3.3hrs. 50 Gallons of 100UL is (50*$8) $350 vs (50*4) $200. But since you had to burn more ethanol (.8 * 15) 12 gallons that's an extra (12* 4) $48. So your total fuel bill is $248 vs $350. Saving $102 per tank. Is that really a downside? A cleaner engine, more power (faster cruise) and about 30% less fuel cost?

Ethanol is already a viable fuel. Has been for decades. There are no downsides that will magically appear. Also I would rather US farmers get my money than places like Venezuela, Russia, Saudi Arabia, Kuwait etc etc.
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The timeline from fuel production to your end use of burning the fuel in your truck is going to be many many times shorter than what we see in GA. This added time from sitting in the bulk tank on the field to sitting the fuel tanks of seldom flown aircraft would bring about a lot of the negatives that come with alcohol.
 
Alcohol has to be adulterated with another substance, generally gasoline, to be able to be sold as a fuel. I am not saying a person can't get the permits to buy and use 100% alcohol but there is a burden there. So whatever that mix is would have to go through all of the testing that we are seeing now with the new fuels. From how it interacts with all materials, storage stability, reliability....
 
mondtster said:
While I would not consider it’s use widespread, it has been used by these guys for decades.

vanguardsquadron.com

Aircraft - Vanguard Squadron

The World's Only 100% Ethanol Powered Airshow Team
vanguardsquadron.com
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I've seen that before. The article is mostly truthful but they have some absence of truth going on. It says, "Ethanol adds power and performance to the Squadron's aircraft without any major engine modifications," which is true but there were engine modifications and fuel systems changes that had to be made.

I don't care about the back & forth over this as Ethanol can be used but there are reasons why it is it not widely used, and those reasons are pretty clear.
 
Dixiebluesky said:
Alcohol has to be adulterated with another substance, generally gasoline, to be able to be sold as a fuel. I am not saying a person can't get the permits to buy and use 100% alcohol but there is a burden there. So whatever that mix is would have to go through all of the testing that we are seeing now with the new fuels. From how it interacts with all materials, storage stability, reliability....
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That research has already been done. Please read the Baylor study. They had to rejet the carb and repitch the prop (ethanol made MORE power than 100LL). That's it.

The FAA CERTIFIED the ethanol fuel. An STC was granted for an O-235 and O-540. That means all the FAA required tests were done and passed.

As for fuel sitting around, again, ethanol doesn't suck water out of the air. So unless there is a storage issue water is not a problem. Tank condensation is gonna happen and can be negated with filters and sensors. Remember, E85 has been a thing since the 2000's. In the past 25 years have there been any significant issues?

"As far as E85 is concerned, according to the New England Interstate Water Pollution Control Commission's L.U.S.T. Line bulletin of May 2006, phase separation may also occur in this fuel, but not as often, since approximately 4% water is needed. This is a large amount of water for a fueling system and would often only result under extreme conditions."

PetroClear - Understanding the Dangers of Phase Separation in Ethanol Blends

petroclear.com petroclear.com


If you consider this: pour a cup of water into a fuel tank of ethanol. The water is absorbed, and burned. Nothing happens. Pour a cup of water into 100LL and the water separates and may enter your pickup tube stopping the engine. You CAN sump the tanks, but the NTSB tells us that this is not always going to happen. So water is bad for gas, and a non-issue for ethanol.

Now pout a gallon of water into that same fuel tank. The ethanol phase separates as it cannot absorb that much water, and the engine burns low octane fuel that may cause damage. The 100LL fuel sits on top of the water, the water goes into the intake and immediately stops the engine. So in first case water stops the 100LL engine but not the ethanol one. In the second case BOTH engines are stopped.

How is water not an issue for 100LL???
 
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Thinking about the transition process and the reality that there will only be 2 fuels max at the airports - 100 gas and Jet. Whatever UL we end up with has to be fungible with current 100LL. A plane needs to be able to use either without requiring it to be modified.

Don’t believe ethanol meets those requirements.
 
pfarber said:
As for fuel sitting around, again, ethanol doesn't suck water out of the air.
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Ethanol sure does suck water from the air! I use ethanol as a chromatography solvent. A few years ago, I had problems with retention time reproducibility using silica columns. I eventually traced it to water adsorbed into the ethanol, and subsequently being adsorbed on the column.

pfarber said:
The water is absorbed, and burned.
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Water is already fully oxidized, it won't burn.

These seem to be contradictory statements:
pfarber said:
Other than a reduction in MPG due to less energy, E85 is a non issue.
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pfarber said:
They had to rejet the carb and repitch the prop (ethanol made MORE power than 100LL)
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pfarber said:
Also I would rather US farmers get my money than places like Venezuela, Russia, Saudi Arabia, Kuwait etc etc.
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It seems the USA is an energy exporter:

U.S. energy facts - imports and exports - U.S. Energy Information Administration (EIA)

U.S. energy imports and exports since 1950.
www.eia.gov www.eia.gov
So our money is staying in the USA.
 
Ever have gas turn into varnish from sitting? Why does gas go bad but 100ll stay viable much longer?
 
To get 100% alcohol, distillate has to then be ran through a molecular sieve. As soon as that alcohol is exposed to the environment it will start to absorb moisture. I am not sure where you are getting that it won't. Parameters would have to be set for just how much water is permissible to be present in aviation fuel. Trying to come up with a protocol to verify water content would also be very difficult. An FBO that was selling aviation alcohol would need a way to not only monitor but document this info for inevitable lawsuits when things start to go wrong.

This doesn't even touch the materials problem that comes with alcohol.
 
Racerx said:
Ever have gas turn into varnish from sitting? Why does gas go bad but 100ll stay viable much longer?
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Short answer, without going into a petrochemical PhD level of detail, is how it's produced. 100LL is one of the few things where you straight distill the stuff you want (nice, clean, stable hydrocarbon molecules). But you can't use that process for motor gasoline, you'd end up throwing away a good chunk of your barrel of oil. So car gas is made by "cracking" the heavier molecules (under heat and pressure, and in the presence of some very interesting catalysts) into lighter ones that can be used in gasolines. But the cracked molecules are not as clean/stable as the straight distillation fractions, and they turn into gums/varnishes a lot quicker.
 
Cap'n Jack said:
These seem to be contradictory statements:
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Ethanol has a lower energy density so you need to burn it faster to get the same power (so your range suffers). But its high octane rating means you can burn it faster and at higher compression ratios, so the engine can produce more power... for a shorter time.
 
Rejetting a carb is a one time expense. The high price of 100UL will remind you at every fuel stop.

Prop pitch is an issue for fixed pitch only. And the FAA accepted the limitation of leaning in the climb for the power / rpm issue.

Seriously READ THE BAYLOR STUDY. Everything negative people are dreaming up has been solved with ethanol fuel. It really is that simple.
 
Dana said:
Ethanol has a lower energy density so you need to burn it faster to get the same power (so your range suffers). But its high octane rating means you can burn it faster and at higher compression ratios, so the engine can produce more power... for a shorter time.
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You are correct- I should have noted that, as the OP should have as well.


pfarber said:
Rejetting a carb is a one time expense. The high price of 100UL will remind you at every fuel stop.

Prop pitch is an issue for fixed pitch only. And the FAA accepted the limitation of leaning in the climb for the power / rpm issue.

Seriously READ THE BAYLOR STUDY. Everything negative people are dreaming up has been solved with ethanol fuel. It really is that simple.
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This study?
It only covers the engine. It doesn't mention effects of ethanol on different fuel tanks (aluminum, bladder), different tank sealants, or fuel lines. "Repitching the prop" was mentioned earlier, so we are already doing more than a "rejetting a carb"
These citations don't mention anything other than the engine either:
https://www.osti.gov/servlets/purl/677075
https://afdc.energy.gov/files/pdfs/2896.pdf
Changing the fuel system to be compatible with ethanol is more than simply "rejetting a carb".

pfarber said:
Tank condensation is gonna happen and can be negated with filters and sensors.
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There's more than tank condensation happening. Sometimes tank cap seals get old and allow water in the plane tanks. With ethanol, that isn't water isn't visible by simply sumping. Adding "filters and sensors" to an aircraft fuel system is also more than "rejetting a carb".
 
AV8R_87 said:
Short answer, without going into a petrochemical PhD level of detail, is how it's produced. 100LL is one of the few things where you straight distill the stuff you want (nice, clean, stable hydrocarbon molecules). But you can't use that process for motor gasoline, you'd end up throwing away a good chunk of your barrel of oil. So car gas is made by "cracking" the heavier molecules (under heat and pressure, and in the presence of some very interesting catalysts) into lighter ones that can be used in gasolines. But the cracked molecules are not as clean/stable as the straight distillation fractions, and they turn into gums/varnishes a lot quicker.
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Look at the compositions of 100LL and automobile gas. The major difference (aside from ethanol in the car gas) is that the car gas has a lot of alkenes to boost octane while the avgas has more aromatic compounds for the same purpose. The alkenes in the car gas polymerize in the same fashion as oil-based paints to form varnish.
 
I will look into the study but a study is just worlds away from actual implementation in the market place. In a study it is very easy to control variables that would make an idea completely impractical. I see no way for alcohol to be used in certified aircraft. A guy could set up an experimental to run alcohol but other than the novelty I see no point to doing it.

When we ran alcohol it was a pain. 90% of the time the motors had to be started on gas to get some heat in them. After racing the whole system had to be flushed with gas again. If you let alcohol sit in the system you had a real disaster, looked like you filled it up with salt water. If you had a fire it's extremely hard to fight for the simple fact that it is so hard to see the flames.
 
LesGawlik said:
I hope they get this sorted out. I would like to see the possibility of synthetic aviation oil (again). We can have that if the fuel is unleaded.
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TL;DR, not too much of that would change with unleaded, I think.

Supposedly there is nothing stopping synthetic now with 100LL other than oil manufacturer cheapness and liability concerns. Most automotive synthetic base stocks are now group III which are derived from and molecularly similar to mineral oil. The failed Mobil AV-1 was a PAO (group IV) base oil with a more uniform molecular structure than mineral oil.

The present Aeroshell 15w-50 is a 50/50 PAO synthetic/mineral oil base stock blend, the discontinued Exxon Elite was a 75/25 PAO blend.

With camguard Aeroshell does pretty well. Even a PAO base stock full synthetic would probably do OK with a properly formulated additive package like camguard. Exxon declined to use what Ed Kollin formulated for their Elite oil due to costs, but his additive package became camguard additive.

Shell, Phillips, and Exxon are all understandably reluctant to change too much because a properly formulated synthetic with the correct additive package would be more expensive than what we have now, with liability concerns, and a limited market.
 
Hengelo said:
Bad news from Blancolirio

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That is the same Cirrus that was at RHV which I reported on in my series of videos on paint and materials testing. It was recently flown to a Cirrus service center near Juan for further inspection and repairs.
 
Glad I'm not a beta tester.

Wonder if action can be taken against the county for taking away 100LL and going against the grant assurances.
 
Cap'n Jack said:
You are correct- I should have noted that, as the OP should have as well.



This study?
It only covers the engine. It doesn't mention effects of ethanol on different fuel tanks (aluminum, bladder), different tank sealants, or fuel lines. "Repitching the prop" was mentioned earlier, so we are already doing more than a "rejetting a carb"
These citations don't mention anything other than the engine either:
https://www.osti.gov/servlets/purl/677075
https://afdc.energy.gov/files/pdfs/2896.pdf
Changing the fuel system to be compatible with ethanol is more than simply "rejetting a carb".


There's more than tank condensation happening. Sometimes tank cap seals get old and allow water in the plane tanks. With ethanol, that isn't water isn't visible by simply sumping. Adding "filters and sensors" to an aircraft fuel system is also more than "rejetting a carb".
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Please see Item #8 where they flew the certificated IO-540 in a SF-260 and didn't mention any of the 'more considerations' in its economic impact statement.

I implore you to read without bias the Baylor papers. Everything you are pointing out has been solved since 1994 (that's when they started the ethanol test, 1996 is when the got the STC.

"The latest FAA certification is for the entire Cessna 152 aircraft, including both the engine and the airframe."

 
I will admit that a 152 is a rather simple AC, but the fuel system was unmodified other than a boost pump and rejet. If an AC does have a bladder then a simple compatibility test is in order. Again, ethanol has been a thing for decades. We know what materials it's harmful to and what it not.

At the end of the day ethanol has a way longer track record than any potion GAMI can come up with and like the saying goes 'you can't please all of the people, all of the time'. The FAA has put out some whopper ADs... retiring incompatible fuel bladders in return for killing 100LL is an option to consider.
 
Cap'n Jack said:
You are correct- I should have noted that, as the OP should have as well.



This study?
It only covers the engine. It doesn't mention effects of ethanol on different fuel tanks (aluminum, bladder), different tank sealants, or fuel lines. "Repitching the prop" was mentioned earlier, so we are already doing more than a "rejetting a carb"
These citations don't mention anything other than the engine either:
https://www.osti.gov/servlets/purl/677075
https://afdc.energy.gov/files/pdfs/2896.pdf
Changing the fuel system to be compatible with ethanol is more than simply "rejetting a carb".


There's more than tank condensation happening. Sometimes tank cap seals get old and allow water in the plane tanks. With ethanol, that isn't water isn't visible by simply sumping. Adding "filters and sensors" to an aircraft fuel system is also more than "rejetting a carb".
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"The fuel system has been modified to burn fuel grade ethanol in accordance
with STC SE8707SW." That STC is not online as far as I can tell, even though its derived from FAA/Gov't funded research.

Seems that AGE-85 (Aviation Grade Ethanol) solves all the corrosion and vapor issues with a blend of bio-diesel.

I'm really not interested in doing people's research... nothing posted here is a deal breaker. Everything has been solved, for over 20 years.
 
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