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how much longer av gas

Billythekid

Well Known Member
anybody ever wonder how much longer general aviation will be around, I mean if cars goto batteries in 30 years then fuel based propulsion and the production of its fuels could be a thing of the past. the plants that make car gas do they make av gas too? and at the same time just at a different time in the process. so if less auto gas is produced based on demand what then is to said for av gas, and to the big picture of aviation, such as the rv community.
 
Oil, grease, and other lubrication products still will be required. IF we use crude oil as a base for the lubrication products, there will be some thin stock byproduct that can be turned into AvGas or some type of fuel as we know it.

Whenever there is a demand for something, someone will figure out a way to supply it and make money.

There are many illegal drugs but since there is a demand, they someone are available. In 30-years if there is a demand for AvGas, someone will be there to supply it even if it is illegal.
 
Fear not Billy. Given the comparative ease of removing the tanks and replacing the engine, any Van's aircraft would make an easy conversion from Avgas to electric, and that's what I'm banking on. In the meantime if you are worried about avgas availability, then if you run an 8.5:1 compression ratio or less, then there is a flavor of mogas out there for you (if you don't have specific lead free avgas available). If burning crushed up dinosaurs isn't your thing, and until they get that battery weight down to a level that will work for us, then you could always increase your injector sizes slightly and run 100% ethanol in your lycosaurus.
Batteries are doubling in energy density every seven years or so, thus at this rate I suspect you'll be driving an electric car within 10 and not 30 years. I also predict it will be around 10-15 years before we have energy densities to make fully electric cross country capable RV's a reality.
Bring on the day that I can charge my RV from sunlight or wind and not have to make some punk in a desert country far away rich everytime I pump juice into my aircraft.
In the meantime, I'd better ride my bicycle back to the hangar and keep building!
Tom.
 
You need to understand how oil refineries work. Crude oil goes in, and out comes bunker oil, diesel/jet fuel, auto/av gas, etc. The refiner can vary the proportions somewhat, but there?s always some of these fuels produced. Back in the 1950?s, before there was a huge demand for jet fuel, diesel was dirt cheap - because the refiners accidently produced more of it than needed to fill demand, in their attempt to meet the demand for car gas. If demand for auto gas goes way down, some of it will still be made anyway - as a by-product of producing jet fuel. Now as to AvGas: it is already a very tiny fraction of the gasoline produced. Refiners dislike it, due to the need to keep any tetraethylead from contaminating their autogas. But who knows? If autogas demand really went to zero, the refiners might sell AvGas cheap, just to get rid of it!
 
TEL

The future problem probably won't be the oil portion of avgas, but the lead portion that makes it the 100LL that most of us use.

My family is in Liverpool, England and was back there last May and this January. Every visit I go to Otterspool Prom (my parent's favourite park) on the River Mersey and look across the river to Ellesmere Port and check that the refinery is still there. :)

It is the sole remaining source for TEL (Tetra Ethyl Lead) in the free world, if it disappears we would have our flying severely curtailed. :eek:
 
So what would it take, as far as mods to the engine, for it to run Mogas?
For instance an IO 540. Sorry I am not an engineer.
The O320 in my Skyhawk can legally use either Avgas or mogas.
 
You could run mogas in a low compression engine safely. Really low, like < 8.5:1. The problem then becomes the loss of power associated with low compression. As well as poor combustion.

The alternative is direct injection. Just like the auto companies are starting to use. Very successfully, I might add. Then compression doesn't matter, and you can kinda have your cake and eat it too. Injecting the gasoline at the moment it needs to start burning on the compression stroke eliminates any chance of detonation or preignition. This would allow very low octane ratings to burn in anything 11:1 maybe 12:1 POWER BABY:D. Low octane fuel is more volatile than higher leaded fuels. They contain more BTU's per gallon and have the potential to make more power than the higher octane fuels. Not to mention the bump in compression.

The problem is then heat. More power is from more heat. How much more can an air cooled engine take? I don't know.

If the compression stayed the same as now and we try to not really ask for more power, the small amount of extra heat might be OK from the direct injection/mogas combination. It would be very expensive, though. As the need for redundancy and safety would require some pretty intricately designed systems. I am sure the price would come down as the systems became more wide spread in use.

IMHO I think small GA aircraft are needing to be powered by tiny turboprops. Jet A is not going anywhere. Can you imagine 300 hp and a 4 blade constant speed on an RV 7? Yes please.
 
I agree that battery technology is advancing quicker than most of us mere mortals can
Comprehend ! However ,inexpensive fuel injection is most likely answer in near term. I
miss my Subaru powered RV 4 ! 2 main controls, ignition switch & throttle ! Burning Mo
gas w alchol all computer adjusted for me !..Tom
 
There's lots more to it than just getting the engine to run on mogas. Others will have more complete answers than I, but some of the factors include:
* winter vs summer blends of mogas (think vapor pressure and vapor lock);
* mogas does not have preservatives in it like avgas, so it will gum things up if left sitting in the airplane too long;
* ethanol content causing corrosion problems;
* ethanol content affecting energy density of the gas;
* ethanol content and water affinity;
* additives in mogas that are incompatible with aircraft gaskets;
* distribution and product purity assurance.

You get the idea... there's lots to it.

Ed
 
Ethanol is added at the final distro point.

IF the gasoline has enough octane and proper vapor pressure- an aircraft could use it if its engine and airframe are compatible.

IF the FAA cannot develop a fuel substitute, at least 90 octane, no ethanol mogas should be easily available.

Boats have had major ethanol issues at the current 10% blends, so many states allow no ethanol mogas.

I run on 50/50 no ethanol mogas and 100LL.

Cleaner plugs, cleaner oil. Savings is a secondary bennie, $2.90 vs. $4.20+ a gallon.

If you can run on 90 octane (r+m/2, average or RON and MON) mogas, and that MOGAS meets vapor pressure, you should be fine when TEL goes away.

The vapor pressure would be my concern, not the access to ethanol free fuel.
 
So what would it take, as far as mods to the engine, for it to run Mogas?
For instance an IO 540. Sorry I am not an engineer.
The O320 in my Skyhawk can legally use either Avgas or mogas.

Standard compression 0 360 parallel valve runs fine on mid grade mogas.

Correct.

Superior Air Parts certificated the 360 Vantage engine using PMA parts they developed for Lycoming engines. According to the TCDS, it was certificated to run on auto fuel. Both the Lycoming parallel valve 360 and 540 use the same cylinder bore, stroke, and parts.

Others have gone before us and shown that it will work.
 
My IO-360 eats a steady diet of 91 premium E10 from Walmart (they run enough fuel sales that I don't worry about old fuel in their tanks). I have 8.7:1 compression with Bendix injection and don't have any issues with detonation/pre-ignition. During Phase I, the engine/fuel mix was tested to try and induce detonation - and I really REALLY had to mis-treat the engine to get to a point where I thought I was seeing detonation. No sane pilot paying halfway decent attention to their airplane would do what I did outside of testing.

Having said that - each installation needs to be properly evaluated - just because it worked for me doesn't mean it will work for all. I eliminated all the natural rubber seals and other components throughout the whole fuel system, substantially modified my fuel delivery system (including removal of the engine-driven fuel pump), insulated the FWF fuel components, and developed my own operating procedures for using that fuel.

It can be done. It won't necessarily be easy in all cases, but it can be done.
 
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The issue is not old fuel in their tanks, the issue is what happens if the plane sits for too long and the fuel system isn?t purged completely. I know of at least one case where this led to a fatal crash.
 
Mogas preservative is about ten cents per gallon. Most say six month duration on their label, assuming you start with "fresh" fuel.

I assume since aircraft fuel tanks are vented, this time should be cut in half to three months.

What did the above investigation reveal?
 
The issue is not old fuel in their tanks, the issue is what happens if the plane sits for too long and the fuel system isn?t purged completely. I know of at least one case where this led to a fatal crash.

I think many would love to read the NTSB summary/report if you've got a link. Otherwise, aircraft type/state/date would be helpful for searching for it.
 
The issue is not old fuel in their tanks, the issue is what happens if the plane sits for too long and the fuel system isn’t purged completely. I know of at least one case where this led to a fatal crash.


Not trying to be argumentative, but where in the NTSB report does it state the crash was due to defective fuel or fuel system? There is no indication in the report that the fuel system hadn't been purged properly. This may have been the case but the report doesn't state that as a cause.

Significant thread drift occurring here.... :)
 
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Electric???

They way we seem to be evolving, I suspect if and when all our vehicles transition to electric power that we'll be wondering what happened to cheap gasoline? Imagine what will happen when the demand for electricity skyrockets - so will the price and so will the need for fuels that we use to power those electric plants. It's hard to come-up with data on this, but right now the emission standards on automobile engines are way stricter than the average coal fired electric power plant. Imagine also the environmental impact associated with meeting that electrical demand! I could be wrong, but I don't think wind, solar and hydroelectric sources of electricity could meet the needs of a country with all electric vehicles. It would be staggering. I'd like to see the oil companies providing lead free, high octane aviation-specific fuel. That would at least address some of the lead issues. Perhaps diesel engines could take care of the rest.

Whatever happened to hydrogen fuel cells??? C'mon, we sent men to the moon with those back in the 60ies, and hydrogen is the most abundant element on earth!
 
The issue is not old fuel in their tanks, the issue is what happens if the plane sits for too long and the fuel system isn’t purged completely. I know of at least one case where this led to a fatal crash.



Not trying to be argumentative, but where in the NTSB report does it state the crash was due to defective fuel or fuel system? There is no indication in the report that the fuel system hadn't been purged properly. This may have been the case but the report doesn't state that as a cause.

Significant thread drift occurring here.... :)


Probable Cause
> THE LOSS OF ENGINE POWER FOR AN UNDETERMINED REASON(S). A FACTOR IN
> THE ACCIDENT WAS THE UNSUITABLE NATURE OF THE TERRAIN ENCOUNTERED
> DURING THE FORCED LANDING.


From the fourth-hand account you linked to, and the Probable Cause found, it could just as well have been carb ice as bad gas. I think I will filter the objection appropriately. Fear-mongering and old wives tales are horrible reasons for doing (or not doing) pretty much anything.
 
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I checked with a friend who has different recollections of that event. There was also speculation at the time that the magnetos had beeswax insulation, absorbed water, and shorted out with steam. Then afterwards, with cool mags, they worked fine.

So who knows?

Sometimes my memory is so good that I remember things that didn't happen...
 
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All of Ed's questions were answered 15 years ago by all auto manufactures,and are not a concern w proper filters( life time) proper hoses,proper lines etc...Tom
 
All of Ed's questions were answered 15 years ago by all auto manufactures,and are not a concern w proper filters( life time) proper hoses,proper lines etc...Tom

Ahhh - and there's the kicker. A large portion of the currently flying GA fleet is aged greater than this 15 year knowledge gap - and the rest of it has been built using knowledge and materials based prior to that 15 year knowledge gap as well.

Assuming you've got 8.7:1 or less compression (and not turbo/supercharged - that indeed does come with other issues), the engine really doesn't care what it burns. What makes the difference today with ethanol-containing mogas is the rest of the fuel system - from the seals on the fuel filler cap to the intake. If you've got any natural rubber components in there at any point, you're going to have a problem. That's the filler cap seals, the sump drain O-rings, the filter and/or check valve seals, the fuel selector valve seals, any fuel hoses themselves, the fuel pumps, pressure gauges/sensors, gascolators if installed, and finally the carbs or injector servo/dividers.

It's not difficult to make the engine happy on a steady diet of ethanol-laced fuel - it's already there. It's the rest of the airframe that's difficult.
 
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Some of this talk about electric planes made me nauseous. Just pushing or pulling a throttle, excuse me, motor speed controller... Ick! The engine balancing act is half the fun and half the character of the plane. If it was up to me, we'd all be running radials :D... Altho, unfortunately, it's a commie engine, I have one in a Moose. I've already lowered my standards running an opposed 4 cyl :rolleyes:

Ahh the fuel. The wonderful smell of 100LL in a loose, air-cooled, oil burning, reciprocating, rotating, puking, smoking, sometimes slobbering, finicky mass of beautiful parts "properly called an engine", not a motor, pulling a plane through the air. What could be better!? May they live forever! Sick huh :)
 
My experience with ethanol in gasoline is that the ethanol is hygroscopic just like automotive break fulid meaning it will absorb moisture from the air ( vented tanks) . Two problems I know that are directly related to water/ moisture in fule are first it will set up corrosion between the dissimilar metals ( think carburetor Aluminum + brass + steel) it can also accumulate a watered up concentration that that will not draw through carburetor jets ( as we know water and gas don't mix but add ethanol and they do) I have seen this first hand more times than I can count on small gas- engine equipment that do a bit of setting inbetween uses,in as little as 2 weeks setting I've had to clean out the float bowl & jets, refill with new fule even if tank was left full to brim this is not a condensation issue from less than full tanks!!

I certainly don't want ethanol anywhere near my airplanes , and unless I know I'll use more than one tank of gas in short order I won't put it in anything else ether (daily driver automobiles excluded) YMMV
 
Some of this talk about electric planes made me nauseous. Just pushing or pulling a throttle, excuse me, motor speed controller... Ick! The engine balancing act is half the fun and half the character of the plane. If it was up to me, we'd all be running radials :D... Altho, unfortunately, it's a commie engine, I have one in a Moose. I've already lowered my standards running an opposed 4 cyl :rolleyes:

Ahh the fuel. The wonderful smell of 100LL in a loose, air-cooled, oil burning, reciprocating, rotating, puking, smoking, sometimes slobbering, finicky mass of beautiful parts "properly called an engine", not a motor, pulling a plane through the air. What could be better!? May they live forever! Sick huh :)

Oh where is the ?like? button!

Bevan
 
Whilst I too could be considered a gear head, there's another angle on this that should possibly be taken into account. There are plenty of people out there (actually the vast majority) that couldn't give a rats what gets them from A to B. If it was a V12 Merlin, or a Retro Encabulator powered by the modial interaction of magneto reluctance and capacitive duractance, they really don't mind, just so long as it's safe, convenient and efficient. These are the people we need to be encouraging to make the transition to a low carbon /low impact means of transportation as soon as possible. The sooner we get them to make this transition, the longer we will be able to continue flying our avgas powered RV's (or lesser types :D). If we as a global society leave that transition until it is all too late, then no-one will be able to do so much as light a match without a UN blessed approval and six authorizing signatures. I'd much rather that it didn't get to this point, so the sooner we can assist others (or other elements of our lives... cars, houses etc) with a transition to a electric/low technology, the longer we can continue to operate our internal combustion beasts.
At least that's my take on it.
Tom.
 
Getting Ethanol out of mogas.

Hey all,

I did an experiment with mogas. I was thinking about this 'alcohol draws water' thing. I made a rig and pumped 10 gallons of mogas through water, then drained the remaining fuel, 9 gallons worth, which makes sense if 10% alcohol is added. The water/alcohol left over smelled like rubbing alcohol.

I ran that fuel in my car for a couple of weeks, no problem. Then I ran another batch, and flew it in one tank on the Kitfox, again no problem.

I did this strictly to satisfy my curiosity. I'm NOT suggesting that everyone do this!
 
From Mahlon: http://www.vansairforce.com/community/showthread.php?t=35765

It lists what compression ratios can run what octane.

As for the never ending debate over ethanol in furl used for aviation, the long term impact of ethanol on the rubber bits in our fuel systems is not good. While one engine manufacturer my bless it, they don't know about all the accessories us builders might put in out planes.

Give me straight MOGASor 100LL. Corn should be drunk and not burned!
 
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