MrNomad
Well Known Member
Here is some disturbing news concerning auto fuel. In the two main cities in the state of Arizona, we’re led to believe that auto fuel contains ethanol from Nov 1 to April 1. In the past, we wait till April 1 and then go ahead and switch to auto fuel.
Not so any more.
On April 10, I purchased auto fuel and put it my 9A. The engine we built has 7.2 compression pistons. It was a brand new Superior O-360 and I specifically confirmed it was suited for auto fuel before I dropped $20k for the build-it-yourself kit.
On AV Gas the 9A pulls 1550 fpm and, despite the outside heat, idles OK on rich setting during flare and landing. But the first thing I noticed with my first tank of auto fuel was during takeoff. Performance was definitely less. During flare and idle settings, the engine seemed rough and having built auto engines for 30 years, I can detect an engine anomaly a mile away.
After 4 touch and goes, I did a full stop but during taxi, the engine stalled. It was running too rich and black smoke was coming out of the pipes. In 59 hours, that engine never stalled, never exhausted black smoke. The only way to keep it running was to lean it... a lot.
Sure enough, using the handy dandy test jar ethanol test routine, I confirmed that some form of alcohol was in the auto gas. I actually tested it before usage but my methods must have been flawed.
BOTTOM LINE: Be suspicious that EVERY state may now include ethanol in their fuel despite state legislation and advertisement otherwise. Apparently, ethanol is cheaper than reg fuel, and obviously, no one cares what happens to unsuspecting pilots who read the sign on the pumps and are aware of governing legislation.
But the problems I experienced with auto fuel are not limited to the destruction ethanol may inflict.
EMPTY TANK TEST: I drained the auto fuel from the right wing and dumped it into my wife's car. Once the right wing was empty, I taxied to the local AV Gas pump using the empty right wing. WHY? The airplane & engine have only 59 hours on it and I wanted to see how it acted when it ran out of fuel. Better to experiment on the ground than the air. The first thing that happened was the Dynon computer alarms went off and reported high rates of fuel flow as high as 94 gph. The electric fuel pump was pushing vapor, not fuel. Of course, I turned the electric pump off.When it finally ran erratically I switched to the left tank.
IN FLIGHT WITH AUTO FUEL: During straight and level flight, the gph with auto fuel was much higher than AV GAS. Whereas I normally see 8 gph, I was seeing 15 gph. It made no sense to me at the time, but after the EMPTY TANK TEST, I see a parallel between the two episodes. Today's auto fuel must have lots of vapor in it and that vapor is producing crazy gph readings and/or getting past the needle valve. Remember, all parts are only 59 hours old. Nothing rebuilt, all new.
IN FLIGHT WITH AV GAS: During subsequent straight and level flight, the gph went back to original readings after the auto gas was replaced with AV Gas. The engine does not stall.
I ordered Peterson Aviation's vapor tester and alcohol tester. It should be here tomorrow (Weds) and I will test the fuel for vapor and post the results to anyone whose interested.
This morning I removed the auto gas from the left wing too. After 18 months of building, I am not going to chance breaking my new toy. For those who are still building, it's worth the pain and suffering. Take it from me, the 9 is a wonderful airplane.
On a related note, friends who use diesel drive to Nogales Mexico and buy diesel for $2.50 a gallon. Why America is paying obscene prices is probably the same reason we pay the most for pharmaceuticals and too much else.
Barry
Tucson
Not so any more.
On April 10, I purchased auto fuel and put it my 9A. The engine we built has 7.2 compression pistons. It was a brand new Superior O-360 and I specifically confirmed it was suited for auto fuel before I dropped $20k for the build-it-yourself kit.
On AV Gas the 9A pulls 1550 fpm and, despite the outside heat, idles OK on rich setting during flare and landing. But the first thing I noticed with my first tank of auto fuel was during takeoff. Performance was definitely less. During flare and idle settings, the engine seemed rough and having built auto engines for 30 years, I can detect an engine anomaly a mile away.
After 4 touch and goes, I did a full stop but during taxi, the engine stalled. It was running too rich and black smoke was coming out of the pipes. In 59 hours, that engine never stalled, never exhausted black smoke. The only way to keep it running was to lean it... a lot.
Sure enough, using the handy dandy test jar ethanol test routine, I confirmed that some form of alcohol was in the auto gas. I actually tested it before usage but my methods must have been flawed.
BOTTOM LINE: Be suspicious that EVERY state may now include ethanol in their fuel despite state legislation and advertisement otherwise. Apparently, ethanol is cheaper than reg fuel, and obviously, no one cares what happens to unsuspecting pilots who read the sign on the pumps and are aware of governing legislation.
But the problems I experienced with auto fuel are not limited to the destruction ethanol may inflict.
EMPTY TANK TEST: I drained the auto fuel from the right wing and dumped it into my wife's car. Once the right wing was empty, I taxied to the local AV Gas pump using the empty right wing. WHY? The airplane & engine have only 59 hours on it and I wanted to see how it acted when it ran out of fuel. Better to experiment on the ground than the air. The first thing that happened was the Dynon computer alarms went off and reported high rates of fuel flow as high as 94 gph. The electric fuel pump was pushing vapor, not fuel. Of course, I turned the electric pump off.When it finally ran erratically I switched to the left tank.
IN FLIGHT WITH AUTO FUEL: During straight and level flight, the gph with auto fuel was much higher than AV GAS. Whereas I normally see 8 gph, I was seeing 15 gph. It made no sense to me at the time, but after the EMPTY TANK TEST, I see a parallel between the two episodes. Today's auto fuel must have lots of vapor in it and that vapor is producing crazy gph readings and/or getting past the needle valve. Remember, all parts are only 59 hours old. Nothing rebuilt, all new.
IN FLIGHT WITH AV GAS: During subsequent straight and level flight, the gph went back to original readings after the auto gas was replaced with AV Gas. The engine does not stall.
I ordered Peterson Aviation's vapor tester and alcohol tester. It should be here tomorrow (Weds) and I will test the fuel for vapor and post the results to anyone whose interested.
This morning I removed the auto gas from the left wing too. After 18 months of building, I am not going to chance breaking my new toy. For those who are still building, it's worth the pain and suffering. Take it from me, the 9 is a wonderful airplane.
On a related note, friends who use diesel drive to Nogales Mexico and buy diesel for $2.50 a gallon. Why America is paying obscene prices is probably the same reason we pay the most for pharmaceuticals and too much else.
Barry
Tucson
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