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Ethanol's Effect

Thats partly why

RV7ator said:
Still, viton o-rings and teflon fuel lines do not get experimenters out of the woods. The one particularly vulnerable fuel system component is the engine driven fuel pump. NO manufacturer I've consulted says the diaphragms are ethanol-tolerant. John Siebold
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I don't have a mechanical fuel pump.

Frank

IO360
electric wing root pumps only, now featuring 10%ETOH
 
I discovered recently that the fuel level gauges that Van's sells have seals that are not ethanol proof.
 
rvbuilder2002 said:
You are probably referring to the black rubber gaskets? I recommend they not be used even if you don't expect to use auto fuel.
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Yes, I am sorry, it is the rubber gasket. Total POS. They dissolve and completely fall apart. The fuel sender works fine! I got some rubber/fiber gasket material and some gasket sealant and know they are bone dry.
 
Yep - this is a known effect on rubber, and is the primary reason that ethanol in aircraft is the big Boogie Man in the closet. You've got to get rid of all the rubber components in the entire fuel feed system, from the filler neck to the engine cylinders.

The experimental world is the perfect place for those of us wanting to run E10 (or higher mixes of EtOH) since we are building the system from the ground up and can quite easily avoid non-compatible materials in the fuel system. I have alodined my fuel-wetted aluminum surfaces, removed all rubber gaskets, and use PTFE hoses (from Bonaco) for the fuel lines. No mechanical fuel pump (rubber diaphragm, vapor lock), I'll use electrics for FI, all set up to take EtOH.
 
airguy said:
>... No mechanical fuel pump (rubber diaphragm, vapor lock), I'll use electrics for FI, all set up to take EtOH.
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Why would anyone "...set up to take EtOH"? It is an oxygenate, that means corrosion. It has less energy than gasoline, that means less range. It loves water. And the main point is, you don't have to do it. We already have a ubiquitous fuel available today and in the future, it is unleaded mogas without ethanol in it. It can be ordered by any fuel business on an airport. No state nor the feds can pass a law mandating ethanol in aviation fuel delivered to an airport, and mogas is an approved aviation fuel, by the STC process.

If we had demanded that 80/87 tanks had been filled with mogas when 80/87 and 91/96 disappeared, we wouldn't be talking about this problem today.

I hope pilots will join our coalition to pass state laws banning the blending of ethanol in premium unleaded gas, at http://www.e0pc.com, and start a movement to get mogas at airports.
 
N1593Y said:
And the main point is, you don't have to do it. We already have a ubiquitous fuel available today and in the future, it is unleaded mogas without ethanol in it.
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That's true IF AND ONLY IF you can find an airport that carries it, within reasonable access to you. Not all do, and not all will. In that case you are forced to fend for yourself if you don't want to shell out for 100LL. My intention is to run ethanol-free mogas to the largest extent possible - BUT - knowing full well that this will not ALWAYS be possible (or practical) I am setting up my fuel system to be fully ethanol-tolerant, or at least E10 tolerant.

Oxygenates in and of themselves do not immediately mean corrosion either - I am a chemist by degree and a corrosion consultant by career, if you really want to joist on this I'm game. There is a greater likelihood of corrosion WITH SOME MATERIALS, yes, but not an immediate blanket increase as you indicated. Steps can be taken (quite easily) to mitigate or eliminate the corrosion potentials when using oxygenates. Caution is advised when making blanket statements like that - someone who knows better may call you on it.

Not hacking on you, just setting the record straight...
 
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rodcritt said:
$1.67 a gallon today for E10
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So what? What is the cost of clear unblended gasoline? Any mogas is cheaper than 100 LL. By putting E10 in your tank you are decreasing your range, so it isn't really $1.67 gasoline.
 
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airguy said:
That's true IF AND ONLY IF you can find an airport that carries it, within reasonable access to you. Not all do, and not all will. In that case you are forced to fend for yourself if you don't want to shell out for 100LL. My intention is to run ethanol-free mogas to the largest extent possible - BUT - knowing full well that this will not ALWAYS be possible (or practical) I am setting up my fuel system to be fully ethanol-tolerant, or at least E10 tolerant. ...
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My whole point was that we need reasonable access, we need to have a program to get mogas on all airports with fuel concessions. It is an approved avgas. Why isn't it on our airports? Years ago there were 4 approved avgas types and three of them were on most airports. All of the aviation alphabets are wringing their hands over the decline in pilot numbers. Well, one of the reasons is because it is such a hassle to get the recommended fuel for most LSA and STCd aircraft now and it is getting worse. Why would any new pilot buy a new $100K+ LSA and be told that he has to put very expensive 100 LL in it and double his maintenance costs, when the recommended fuel should be on every airport.

What difference would it make to set up your fuel system for E10. You are not going to find that on any airport anywhere. The only time you will use E10 is when you are on your home airport, by self-fueling your bird with it. That being the case you can always find unblended mogas. It may not be easy or convenient but you can do it, especially if we get state laws passed to prohibit blending ethanol in premium gasoline, like Missouri already does and Montana would have done had their mandatory E10 law ever triggered. Once a few states pass such a law maybe Congress will take notice and amend EISA 2007 to prohibit ethanol blending in premium unleaded, which they should have done originally, but then again EISA 2007 isn't a mandatory E10 law, and the fact that we are getting E10 everywhere is just and unintended consequence.
 
All your points are true and valid - but in some aspects I think maybe they are overly optimistic. Yes, we need reasonable access to ethanol-free premium mogas on all airports. No, we're not likely to get that. Yes, it's a legally defined aviation fuel and as such, it will always be available FOR BULK PURCHASE. No, FBO's are not legally required to provide that fuel. They MAY do so if it is economically in their best interest - but it's ultimately a business decision on the part of the FBO owner.

My view is that I do not want to paint myself into a corner by building an aircraft that is not capable of swallowing E10, in the hopes that ethanol-free mogas will be available at all places and all times. It is very easy for me (at this point) to build the fuel system to be tolerant of ethanol blends, which gives me options for fueling the bird in the event that ethanol-free mogas or 100LL are either unavailable or impractical. For my homebase, I will have a 75-gallon tank with electric pump in the bed of my truck to fuel my aircraft. When elsewhere, the airplane will swallow 100LL or mogas perfectly fine - with or without ethanol.

You pointed out that range is slightly reduced with E10 - this is true, but at the current price of E10 versus 100LL, your dollar-specific range (miles per dollar) is significantly increased, so the only real problem is that your maximum distance between fillups is slightly shorter. In my case that's not a problem at all - I will have 70 gallons of tank capacity, well beyond what would be needed for any realistic domestic US one-way trip from my Texas base, not to mention beyond bladder range. That capacity would allow me to fly to Chicago and back without refueling - which might just come in handy on occasion.

While I understand completely (and agree with) your points about needing ethanol-free premium mogas on easy-access airports, I think the best way to accomplish that goal is to work together and lobby FBO's to stock that fuel - not to attack someone who is building a fuel system in their airplane that is capable of operating on fuel that you don't like. Just because I CAN use E10 does not mean I always will - but it means I CAN. Having other options available is NEVER a bad thing.
 
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airguy said:
All your points are true and valid - but in some aspects I think maybe they are overly optimistic. Yes, we need reasonable access to ethanol-free premium mogas on all airports.
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How about ethanol-free mogas of all grades? Some of us can run 80 octane and shouldn't have to pay for premium. (Just arguing for arguments sake.)

airguy said:
...You pointed out that range is slightly reduced with E10 - this is true, ...
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It also reduces power output so your weight lifting capability, climb rates, etc. are all reduced and takeoff distance lengths increase. This is one of the big issues, it would require re-testing every airplane and revising their POH's for the reduced performance. Don't forget, there are a number of certified airplanes using mogas.

I suspect many of the FBO's out there have removed and/or replaced their old 80 octane tanks so it is not as easy as just using those tanks, pumps, etc. for mogas.

Since ethanol is typically added at the local tank farms, I doubt it would be that much of a problem for them to fill up a tanker with "clean" mogas for delivery to your local airport. In addition, no longer would they be required to use a designated tanker as they wouldn't have to worry about led contamination.

Of course, I could be wrong on all that. I sure wish we had someone who works in the oil/gas distribution segment who could set us straight.
 
N941WR said:
How about ethanol-free mogas of all grades? Some of us can run 80 octane and shouldn't have to pay for premium. (Just arguing for arguments sake.)
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Lets start with the basics first. It's going to be difficult enough as it is to convince FBO's to carry premium non-ethanol mogas with the low market demand that we have currently. For them, it is the ultimate "boutique" fuel. The demand (usage) will have to increase considerably for them to consider it a profitable exercise. Without profit, it won't happen. Nobody is forcing you to pay for premium, or 100LL, or E10, or orange juice, milk, or anything else. It's a free market - if you want it, you buy it. Don't wanna buy it? So don't buy it....


N941WR said:
It also reduces power output so your weight lifting capability, climb rates, etc. are all reduced and takeoff distance lengths increase.
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Realistically, RV's will not be affected in this area. We already have airplanes with very good performance. If the difference between 100LL and E10 means the difference between getting out of that short strip or not, then you shouldn't be on that short strip in the first place - the margin is too tight.

N941WR said:
This is one of the big issues, it would require re-testing every airplane and revising their POH's for the reduced performance. Don't forget, there are a number of certified airplanes using mogas.
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I can't solve all problems for all people - I'll leave that for Barak Obama. I can however solve my own problems, and perhaps pave the way for others to see a path to solving their own. If you own an airplane that can only run 100LL, I can't help you and neither can anyone else - but there are an awful lot of airplanes that can gain an awful lot of utility by having other fuel options available. Don't let perfect be the enemy of good. Chemotherapy won't solve all cancer cases either - but you don't see many people turning it down because it's not universally effective.

N941WR said:
I suspect many of the FBO's out there have removed and/or replaced their old 80 octane tanks so it is not as easy as just using those tanks, pumps, etc. for mogas.

Since ethanol is typically added at the local tank farms, I doubt it would be that much of a problem for them to fill up a tanker with "clean" mogas for delivery to your local airport. In addition, no longer would they be required to use a designated tanker as they wouldn't have to worry about led contamination.
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Most likely correct - I would wager that a good majority of those tanks have been ripped out to comply with environmental regs, which will make it that much harder to get the FBO's to gear up again for another fuel choice.
 
airguy said:
Lets start with the basics first. It's going to be difficult enough as it is to convince FBO's to carry premium non-ethanol mogas with the low market demand that we have currently. For them, it is the ultimate "boutique" fuel.
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Interesting observation. The ultimate "boutique" fuel is 100 LL, less than 500 million gallons made a year and declining every year, made by maybe 8 refineries of the 400+ in the US. Unleaded mogas is made everywhere and available everywhere and could be used by 70% of the GA fleet and 100% of the new LSA fleet. I understand that a number of branded FBOs are forced to take 100 LL in order to keep their Jet-A branded service.

The demand (usage) will have to increase considerably for them to consider it a profitable exercise. Without profit, it won't happen.
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Sort of a chicken and egg scenario. There would be more mogas users if the airports had it. More airports would have it if there were more users. It will be interesting to see what happens when TEL disappears in a few years at the most. If the FBOs had mogas they could still service 70% of their customers. Hope SwiftFuels makes it before TEL disappears.

Nobody is forcing you to pay for premium, or 100LL, or E10, or orange juice, milk, or anything else.
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Yes, but if you need mogas the gasoline distributors are forcing you to buy ethanol, unless the states wise up and prohibit it, so that aviation has a supply. Currently only the six mandatory E10 states provide an exemption for aviation use, but make no guarantee that anyone but an FBO on an airport can order it, and even that can be difficult unless you can take a tank trailer load. Only Missouri guarantees that you can buy ethanol free premium unleaded at every service station, airport and marina.
 
When Does lead have to be added?

N1593Y said:
Interesting observation. The ultimate "boutique" fuel is 100 LL, less than 500 million gallons made a year and declining every year, made by maybe 8 refineries of the 400+ in the US. Unleaded mogas is made everywhere and available everywhere and could be used by 70% of the GA fleet and 100% of the new LSA fleet. I understand that a number of branded FBOs are forced to take 100 LL in order to keep their Jet-A branded service.


Sort of a chicken and egg scenario. There would be more mogas users if the airports had it. More airports would have it if there were more users. It will be interesting to see what happens when TEL disappears in a few years at the most. If the FBOs had mogas they could still service 70% of their customers. Hope SwiftFuels makes it before TEL disappears.


Yes, but if you need mogas the gasoline distributors are forcing you to buy ethanol, unless the states wise up and prohibit it, so that aviation has a supply. Currently only the six mandatory E10 states provide an exemption for aviation use, but make no guarantee that anyone but an FBO on an airport can order it, and even that can be difficult unless you can take a tank trailer load. Only Missouri guarantees that you can buy ethanol free premium unleaded at every service station, airport and marina.
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Would it be possible for the lead to be added to Mo-gas during the dispensing phase, i.e., post-transport?

I am not a chemist/chemical engineeer, so this may be an ignorant question, but here goes: could an equipment system to safely handle the introduction of lead at the time the gasoline was dispensed be developed so that FBOs could have one tank. The volume of gas is quite large compared to the volume of lead. The gasoline tanker is already hauling hazardous material. If this is possible why couldn't they just haul a can of tetraethyl lead in a safe onboard compartment. The can could have some kind of dry break connector, like a water cooler bottle or gasoline dispenser breakaway connector. (In the old days, before the risks were widely recognized and accepted, it was not uncommon for auto racers to add TTL to gasoline to run higher compression engines. This is where I got the impression that TTL could be added at the last minute).

Larry
 
N1593Y said:
Interesting observation. The ultimate "boutique" fuel is 100 LL, less than 500 million gallons made a year and declining every year, made by maybe 8 refineries of the 400+ in the US. Unleaded mogas is made everywhere and available everywhere and could be used by 70% of the GA fleet and 100% of the new LSA fleet. I understand that a number of branded FBOs are forced to take 100 LL in order to keep their Jet-A branded service.
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In an absolute production standing, yes. But from the aspect of sales at the airport, there is a much, much larger demand for 100LL (today, anyway) than for ethanol-free premium mogas. From the standpoint of the FBO and their economics, 100LL is the standard and mogas is the boutique fuel. My personal belief is that this situation will likely continue until the spectre of TEL going away becomes very real and is looming on the horizon, then the FAA will "suddenly" come to the discovery that all those 100LL engines (or most of them anyway) can run just fine on premium mogas. Not until we have FAA and manufacturer approval for the majority of the fleet to run mogas will the FBO's stock it. It's just a business decision for them - the dollars are in 100LL today, not mogas.
 
N941WR said:
It also reduces power output so your weight lifting capability, climb rates, etc. are all reduced and takeoff distance lengths increase. This is one of the big issues, it would require re-testing every airplane and revising their POH's for the reduced performance. Don't forget, there are a number of certified airplanes using mogas.

.
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Hmm..I can honestly say i have not noticed any reduction in power output running E10..It won't lean out as far (7.5GPH vs 7.0 on straight mogas) but climb rates don't seem to be affected.

Frank 7a IO360 now featuring 10% ETOH
 
Interesting Info on Alcohol in Gasoline

http://www.chevron.com/products/ourfuels/prodserv/fuels/technical_safety_bulletins/

I came across this publication by Chevron on gasoline. It has a section on alcohols and their effects on gasoline and the reasons that alcohol is used, its effects and how it is added and why alcohol is not added at the refinery. There is a discussion on phase separation that was talked about in this thread earlier and how it can happen in a fuel tank.

There are a number of pdf's, the one on aircraft fuel seems to be jet fuel although I did not go through it completely to see if gasoline was there.

There is also interesting reading on what is being developed in spark ignition engines.

Have a good and safe New Year everyone.

Bob Parry
 
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