Re: Auto Gas Users
Posted: Sat Apr 30, 2011 5:36 pm
Steve and Glenn.... both your posts make perfect sense to me. As an old pipeline patrol pilot, I understand the frequent activity of the patrol plane. That is a perfect example of how frequent useage is good for engine longevity.
In other words.... I don't think the use of mogas explains the cause for the 3000 life/TBO. Similar lifetimes were experienced in our patrol planes when we used 80/87 avgas.
This leaves the question as to whether or not mogas prevented the long engine-life...and apparently the frequent flying kept the gas fresh...which is a major concern when using mogas. The other observation is the availability of non-ethanol fuels in MT would imply the fuel system components were not adversely affected.... another serious matter with the E10 mogas now prevalent.
Ethanol is a powerful solvent and it washes accumulations (which were harmless while accumulated...but potentially harmful once released by the ethanol) from the system and sends it on to the carburetor. The ethanol/mogas also attacks older fuel-system components. (I believe this is evidenced by the change-of-color of your fuel, Glenn. The ethanol likely dissolved compnents of the rubber lines/gaskets and contributed to the amber color.) Both the auto and the marine industries have recognized this latter problem and converted their materials used in autos/boats to ethanol-resistant materials. One of the USBoat links I posted previously make mention of that when they pointed out that marine users of E10 should change-out their rubber fuel lines to modern spec rubber lines. I experienced a similar problem with an old "ranch truck" we keep out here. It was my wife's Father's truck...a '78 GMC which originally had two fuel tanks but one of them rusted out (probably from water-phased-out ethanol) and leaked, so that tank was disabled. The other tank was re-routed completely via a rubber fuel line directly to the fuel pump (to bypass the dual-tank system.) That rubber line self-destructed every year and the particles blocked the in-line fuel filter....until I replaced that line with modern ehtanol-approved fuel line.
Unfortunately, that connot be done quite so easily on 60 year old airplanes that can use only FAA-approved-materials. The carburetor/pump OEMs and PMAs cannot simply substitute E10-resistant materials without going thru the FAA approval process... and all of these concerns are doubtless why Continental, Lycoming, Cessna, and others adhere to their mantra's of NO autogas or alcohol-based fuels.
If cleanliness/purity/freshness/alcohol/phase-separation/fuel-system-components issues were properly addressed...I'd have no qualms about using mogas. I hate the lead in avgas. It is harmful stuff, not only to us but to our engines. I'd love to be able to exclude it from my airplane's fuel.
I'd also love to be able to use a "cheaper* fuel such as that which is commonly available for all other gasoline-powered vehicles. But my airplane's fuel system is not built for it, and the fuel has ethanol in it, and I cannot let the airplane sit for any length-of-time with the stuff, and the repair bills for using the stuff detract from any savings, while the safety-issues of using the stuff take the situation out of my comfort-zone.
* I recall a few years back when avgas was cheaper than mogas due to a temporary aberration in fuel-markets. I used avgas in my tactor to mow my runway. When I posted that in a thread, many mogas users admitted the only reason they used mogas was cost...that they'd almost universally use avgas if it cost the same or less than mogas. At that time I think I remarked that avgas is actually not good for our engines because of the lead in it. This seeming reversal of matters provoked a completely different firestorm of opinions, not only here, but in some other aviation periodicals, due to the (ridiculous, in my opinion) common beliefs/statements by OEMs that lead is "necessary" to lubricate valves....pure B.S. in my opinion. A certain well-known aviation writer (his second-career after having retired from a major oil refiner) ridiculed my assertion that lead wasn't necessary for valve lubrication, and began a series of taunts I felt directed toward me, quoting those engine mfr's insistence upon lead for valve lubrication.
I challenged him and the engine mfr's to produce any evidence whatsoever they could, that engines once-suffered valve problems...and that tetraethyl lead was introduced into fuels for the purpose and result of ending the valve problems. That has been at least three years now and they have not risen to the challenge. They changed the subject of their articles. (It is my contention/belief that TEL was introduced for the single purpose of raising aparent octane levels of fuel, necessary to prevent detonation in ever higher compression engines. Is it so strange to notice that my 1939-design 9-N Ford tractor runs just fine on ethanol gas with absolutely no valve problems? Is anyone going to notice that the valve problems are non-existant in an engine clearly designed prior to the mass introduction of those TEL fuels? In fact, that engine was expected to be "multi-fuel"... (how many kids today think that is a "modern" concept?)
Isn't it interesting that Henry Ford personally and corporately attempted to get auto makers to use 100% ethanol for auto fuels back in the 1930's? He realized (in that time-frame-economy) that farmers would benefit from 100% ethanol. Their corn prices would increase, and they could use his tractors....the 9N Fords...which had hardened valve seats.... which run just fine on unleaded gasoline or ethanol. But his nemesis General Motors teamed up with chemical giant DuPont and subsidiary "Ethyl Corporation" to promote the use of tetraethyl-lead additives in gasoline...and now you know the rest of the story.
It is my belief that lead masked the erosion which will occur with the use of inferior valve materials/design...and that allowed engine-mfr's to get away with cheap materials for valves. It wasn't until the reduction of lead in fuels that deficient valve-design became apparent. A change of alloys and valve-seat angles cured the "problem" of no/low-lead fuels. That sequence of events mis-led some to believe that tetraethyl lead was necessary for valve lubrication....and old ideas die hard. Some replacement cylinder mfr's still insist upon leaded fuels during break-in. I believe they are simply "covering their arses" with suggesting a safe-bet on a fuel they know will be used only temporarily in many engines....after-all....they can't be held liable for suggesting the use only of approved-fuels.... and any valve problems resulting from long-term use of leaded-fuel will be beyond their warranty-period.
In other words.... I don't think the use of mogas explains the cause for the 3000 life/TBO. Similar lifetimes were experienced in our patrol planes when we used 80/87 avgas.
This leaves the question as to whether or not mogas prevented the long engine-life...and apparently the frequent flying kept the gas fresh...which is a major concern when using mogas. The other observation is the availability of non-ethanol fuels in MT would imply the fuel system components were not adversely affected.... another serious matter with the E10 mogas now prevalent.
Ethanol is a powerful solvent and it washes accumulations (which were harmless while accumulated...but potentially harmful once released by the ethanol) from the system and sends it on to the carburetor. The ethanol/mogas also attacks older fuel-system components. (I believe this is evidenced by the change-of-color of your fuel, Glenn. The ethanol likely dissolved compnents of the rubber lines/gaskets and contributed to the amber color.) Both the auto and the marine industries have recognized this latter problem and converted their materials used in autos/boats to ethanol-resistant materials. One of the USBoat links I posted previously make mention of that when they pointed out that marine users of E10 should change-out their rubber fuel lines to modern spec rubber lines. I experienced a similar problem with an old "ranch truck" we keep out here. It was my wife's Father's truck...a '78 GMC which originally had two fuel tanks but one of them rusted out (probably from water-phased-out ethanol) and leaked, so that tank was disabled. The other tank was re-routed completely via a rubber fuel line directly to the fuel pump (to bypass the dual-tank system.) That rubber line self-destructed every year and the particles blocked the in-line fuel filter....until I replaced that line with modern ehtanol-approved fuel line.
Unfortunately, that connot be done quite so easily on 60 year old airplanes that can use only FAA-approved-materials. The carburetor/pump OEMs and PMAs cannot simply substitute E10-resistant materials without going thru the FAA approval process... and all of these concerns are doubtless why Continental, Lycoming, Cessna, and others adhere to their mantra's of NO autogas or alcohol-based fuels.
If cleanliness/purity/freshness/alcohol/phase-separation/fuel-system-components issues were properly addressed...I'd have no qualms about using mogas. I hate the lead in avgas. It is harmful stuff, not only to us but to our engines. I'd love to be able to exclude it from my airplane's fuel.
I'd also love to be able to use a "cheaper* fuel such as that which is commonly available for all other gasoline-powered vehicles. But my airplane's fuel system is not built for it, and the fuel has ethanol in it, and I cannot let the airplane sit for any length-of-time with the stuff, and the repair bills for using the stuff detract from any savings, while the safety-issues of using the stuff take the situation out of my comfort-zone.
* I recall a few years back when avgas was cheaper than mogas due to a temporary aberration in fuel-markets. I used avgas in my tactor to mow my runway. When I posted that in a thread, many mogas users admitted the only reason they used mogas was cost...that they'd almost universally use avgas if it cost the same or less than mogas. At that time I think I remarked that avgas is actually not good for our engines because of the lead in it. This seeming reversal of matters provoked a completely different firestorm of opinions, not only here, but in some other aviation periodicals, due to the (ridiculous, in my opinion) common beliefs/statements by OEMs that lead is "necessary" to lubricate valves....pure B.S. in my opinion. A certain well-known aviation writer (his second-career after having retired from a major oil refiner) ridiculed my assertion that lead wasn't necessary for valve lubrication, and began a series of taunts I felt directed toward me, quoting those engine mfr's insistence upon lead for valve lubrication.
I challenged him and the engine mfr's to produce any evidence whatsoever they could, that engines once-suffered valve problems...and that tetraethyl lead was introduced into fuels for the purpose and result of ending the valve problems. That has been at least three years now and they have not risen to the challenge. They changed the subject of their articles. (It is my contention/belief that TEL was introduced for the single purpose of raising aparent octane levels of fuel, necessary to prevent detonation in ever higher compression engines. Is it so strange to notice that my 1939-design 9-N Ford tractor runs just fine on ethanol gas with absolutely no valve problems? Is anyone going to notice that the valve problems are non-existant in an engine clearly designed prior to the mass introduction of those TEL fuels? In fact, that engine was expected to be "multi-fuel"... (how many kids today think that is a "modern" concept?)
Isn't it interesting that Henry Ford personally and corporately attempted to get auto makers to use 100% ethanol for auto fuels back in the 1930's? He realized (in that time-frame-economy) that farmers would benefit from 100% ethanol. Their corn prices would increase, and they could use his tractors....the 9N Fords...which had hardened valve seats.... which run just fine on unleaded gasoline or ethanol. But his nemesis General Motors teamed up with chemical giant DuPont and subsidiary "Ethyl Corporation" to promote the use of tetraethyl-lead additives in gasoline...and now you know the rest of the story.
It is my belief that lead masked the erosion which will occur with the use of inferior valve materials/design...and that allowed engine-mfr's to get away with cheap materials for valves. It wasn't until the reduction of lead in fuels that deficient valve-design became apparent. A change of alloys and valve-seat angles cured the "problem" of no/low-lead fuels. That sequence of events mis-led some to believe that tetraethyl lead was necessary for valve lubrication....and old ideas die hard. Some replacement cylinder mfr's still insist upon leaded fuels during break-in. I believe they are simply "covering their arses" with suggesting a safe-bet on a fuel they know will be used only temporarily in many engines....after-all....they can't be held liable for suggesting the use only of approved-fuels.... and any valve problems resulting from long-term use of leaded-fuel will be beyond their warranty-period.