AV gas prices

And now with the link...

http://www.autofuelstc.com/autofuelstc/pa/ethanol.html

"Gig 601Xl Builder" wrote in message
m...
And now with the link...

http://www.autofuelstc.com/autofuelstc/pa/ethanol.html

Thanks Gig. I missed that page. The problem that I have with some of the
reporting is that there isn't much supportive data. To wit: Corrosion of
aircraft fuel systems. Specifically what systems and what are the
differences in auto that allow them to use the E-10 with apparent immunity?
I've heard that the gravity fed fuel systems don't seem to experience the
vapor locking and I've never experienced carb ice in any vehicle but my VW.
The CAT gage on my Lycoming never gets within a large margin of the yellow
zone and even in Canada along side the lakes with temps in all ranges from
20 F to 80 F have I ever encountered any hint of carb ice in my
installation. Now with the metal floats in the carburetors, I can't see how
alcohol would affect that. Some of the O rings in the gascolators and fuel
shut off valves might need changing. I fully expect to lose some power
using Supreme with 10% ethanol, but at price differentials exceeding $1.00/
gal?
I'm going to get some 10% Ethanol Supreme and put one of my A/C quality
fuel lines in it and let it soak.

Thanks again for the link. BTW are you going to Oshkosh this year? We will
be covering the helicopters down at the Ultralite runway again.
Stu

On Mon, 28 Apr 2008 21:13:16 -0700, "Stuart & Kathryn Fields"
wrote:

Well it has happened. Local 100LL is $5.60/ gal and is not expected to
decrease. Is there anyone out there using Supreme MoGas in a Lycoming
0320
with 8.5:1 compression? If so what ignition timing changes were needed if
any?

thanks
Stu Fields

I have an 0-320 clone from ECI 160hp with an Emag Pmag electronic
ignition. The ignition has a feature that allows me to switch between
maximum advance depending on the fuel being used. I believe it's a 4
degree difference but that's just from memory you might find some
usefull information poking around the emagair site. I haven't used any
mogas yet cuz I'm in a fuel co-op and right now 100LL is 7 cents a
litre cheaper than regular unleaded.

Stuart & Kathryn Fields wrote:
"Gig 601Xl Builder" wrote in message
m...
And now with the link...

http://www.autofuelstc.com/autofuelstc/pa/ethanol.html

Thanks Gig. I missed that page. The problem that I have with some of the
reporting is that there isn't much supportive data. To wit: Corrosion of
aircraft fuel systems. Specifically what systems and what are the
differences in auto that allow them to use the E-10 with apparent immunity?
I've heard that the gravity fed fuel systems don't seem to experience the
vapor locking and I've never experienced carb ice in any vehicle but my VW.
The CAT gage on my Lycoming never gets within a large margin of the yellow
zone and even in Canada along side the lakes with temps in all ranges from
20 F to 80 F have I ever encountered any hint of carb ice in my
installation. Now with the metal floats in the carburetors, I can't see how
alcohol would affect that. Some of the O rings in the gascolators and fuel
shut off valves might need changing. I fully expect to lose some power
using Supreme with 10% ethanol, but at price differentials exceeding $1.00/
gal?
I'm going to get some 10% Ethanol Supreme and put one of my A/C quality
fuel lines in it and let it soak.

Thanks again for the link. BTW are you going to Oshkosh this year? We will
be covering the helicopters down at the Ultralite runway again.
Stu



The biggest problem IMHO is that it holds water. All the other issues
such as it eating the rubber can be dealt with but you can't make
Ethanol not hold water.

As for OSH this year I don't know. Hopefully about that time I will be
finishing up the engine install on my 601XL and since I have waited a
while to get the engine (technically I still am waiting)I'm going to be
hard pressed to make myself break away from building to make it. But
Hell or high water I will be there in 2009 and will be spending quite a
bit of time down with the helos because I really want to build a Mosquito.

And speaking of the Mosquito. Will those floats on the UL version really
float the helo and would the deployable floats from say a Bell 206
qualify the Mosquito to still be flown as a UL?

Gig 601Xl Builder wrote:



The biggest problem IMHO is that it holds water. All the other issues
such as it eating the rubber can be dealt with but you can't make
Ethanol not hold water.



Turn it around, Gig.

Look at it as a safety feature.

Ethanol in the fuel might absorb any water in the tanks
avoiding an engine failure.



Richard
--
(remove the X to email)

Now just why the HELL do I have to press 1 for English?
John Wayne

cavelamb himself wrote:
Gig 601Xl Builder wrote:



The biggest problem IMHO is that it holds water. All the other issues
such as it eating the rubber can be dealt with but you can't make
Ethanol not hold water.



Turn it around, Gig.

Look at it as a safety feature.

Ethanol in the fuel might absorb any water in the tanks
avoiding an engine failure.



Richard


That's what all those drains are for. My little 601 will have three
places designed to get water out of the fuel before it gets sucked in to
the engine.

"Gig 601Xl Builder" wrote in message
m...
cavelamb himself wrote:
Gig 601Xl Builder wrote:



The biggest problem IMHO is that it holds water. All the other issues
such as it eating the rubber can be dealt with but you can't make
Ethanol not hold water.



Turn it around, Gig.

Look at it as a safety feature.

Ethanol in the fuel might absorb any water in the tanks
avoiding an engine failure.



Richard


That's what all those drains are for. My little 601 will have three places
designed to get water out of the fuel before it gets sucked in to the
engine.

Richard's poiint was well worth noting. AFAIK, in automobiles, wich
generally have no drains, when a problem of water in the fuel tank is
encountered, it is normally resolved by adding alcohol. One of the other
alcohols is normally used, because of the beverage tax applied to pure
ethanol; but, according to my local mechanic, that gets the car running so
that the fuel can be successfully consumed in the normal way. At least in
theory, that would result in a slight and temporary reduction in horsepower;
but it is hard to imagine a situation where the loss would exceed 5 of 10
percent--even on a carbureted engine.

Peter

"Sliker" wrote in message
...
I've got the same engine in my plane, it's an O-320 D2C, but there are
other number series with the same compression ratio in the 160hp
class. That engine is listed on Peterson's mogas STC site as one that
is approved for premium unleaded autofuel. So you shouldn't run into
any problems as far as detonation goes, vapor lock is another issue,
and is different in each aircraft type. Just the other day a pilot at
my local airport said that if the gas has the common 10% ethanol
added, it's vapor lock potential goes up a lot. I'm not sure about
those facts, but I think it has more to do with fuel system design.
Gravity flow systems seem almost immuned to that problem. With wing
tanks below the carb, the best setup is to have fuel pumps at the tank
"pushing" the fuel to the carb. Rather than the more common setup of
the fuel pump in the engine compartment sucking the fuel from the
tank. Peterson's website has a good dissertation about homebuilts
worth reading, in regards to fuel system design to help prevent vapor
lock.

Back when the Mogas STCs, or "Autogas STC" as they were then called, were
being proposed, tested, and certified; all of these issues and more were
quite hotly debated in "Sport Aviation", "AOPA Pilot", "Flying", and I
believe "Aviation Maintenance" and "Aviation Consumer", to name just a few.

At that time, some of the original researchers were still in good
health--who were present when the Av-Gas Mil Spec was first written. At
least one of them asserted that there was considerable doubt that the very
low vapor presure spec was usefull, and that it was the result of an error
at the time; but that there had simply never been a strong enough motivation
to change it, since the engines ran well on the fuel as specified.

So the bottom line is probably that the REAL problem with adding 10% ethanol
to the STCs might be that the automotive fuel formula would subsequently be
changed to a greater percentage, or possibly to some other additive or
dilutant. Then the entire tedious and costly process would need to be
duplicated yet again.

Also, just as a reminder, the original motivation was to allow Mogas to be
sold by FBOs as a replacement for 80-87 Avgas. The cost it was mainly
intended to reduce was the expense and downtime that occurred due to fouled
valves and spark plugs--especially in trainers which were commonly operated
with full-rich mixture much of the time.

Peter

On Wed, 14 May 2008 14:27:06 -0700, "Stuart & Kathryn Fields"
wrote:


"Sliker" wrote in message
.. .
I've got the same engine in my plane, it's an O-320 D2C, but there are
other number series with the same compression ratio in the 160hp
class. That engine is listed on Peterson's mogas STC site as one that
is approved for premium unleaded autofuel. So you shouldn't run into
any problems as far as detonation goes, vapor lock is another issue,
and is different in each aircraft type. Just the other day a pilot at
my local airport said that if the gas has the common 10% ethanol
added, it's vapor lock potential goes up a lot. I'm not sure about
those facts, but I think it has more to do with fuel system design.
Gravity flow systems seem almost immuned to that problem. With wing
tanks below the carb, the best setup is to have fuel pumps at the tank
"pushing" the fuel to the carb. Rather than the more common setup of
the fuel pump in the engine compartment sucking the fuel from the
tank. Peterson's website has a good dissertation about homebuilts
worth reading, in regards to fuel system design to help prevent vapor
lock.

On Mon, 28 Apr 2008 21:13:16 -0700, "Stuart & Kathryn Fields"
wrote:

Well it has happened. Local 100LL is $5.60/ gal and is not expected to
decrease. Is there anyone out there using Supreme MoGas in a Lycoming
0320
with 8.5:1 compression? If so what ignition timing changes were needed if
any?

thanks
Stu Fields

Sliker: Thanks for the answer. Most of the rest of the responses ignored
my question but assumed that I needed either a course in accounting or
fossel fuel economics, or some barroom counseling in an attempt to reduce my
grief over the increased fuel prices.
I looked into the Peterson site and got a bunch of useful info. I've also
found several University studies that have looked into alternative fuels to
and including 100% ethanol. More studying is required.
Somewhere in my excellent memory that I have limited access to, is an
anecdote of some guy who has been using MoGas in his Lycoming equipped
Stinson for quite a few years. The ethanol aspect was not discussed and his
history certainly started before the ethanol additive.
For the very near future I will be mixing Supreme with 100LL until the LL
runs out. When I switch to 100% Supreme, I will be hovering my helicopter
for a few hours and keeping track of the CHT, EGT, MP etc.

Not a safe thing to do.
You must have not read the petersen page about not using gas with
alcohol added.



Thanks again for useful response.

stu

Roger (K8RI) ARRL Life Member
N833R (World's oldest Debonair)
www.rogerhalstead.com

On Wed, 14 May 2008 17:03:17 -0700, "Stuart & Kathryn Fields"
wrote:


"Gig 601Xl Builder" wrote in message
om...
And now with the link...

http://www.autofuelstc.com/autofuelstc/pa/ethanol.html

Thanks Gig. I missed that page. The problem that I have with some of the
reporting is that there isn't much supportive data. To wit: Corrosion of
aircraft fuel systems. Specifically what systems and what are the

The problem is Alcohol and bare unprotected aluminum don't mix. IOW,
Alcohol his highly hygroscopic.(IT not only absorbs water - A little
will dissolve liquid water into gas preventing gas line freeze -
"DryGas", but is corrosive to Aluminum

differences in auto that allow them to use the E-10 with apparent immunity?

Automotive fuel systems use steel fuel lines although for E85 they
should be using SS lines and tanks, but I doubt any do. Those fuel
systems are also living on borrowed time.

I've heard that the gravity fed fuel systems don't seem to experience the
vapor locking and I've never experienced carb ice in any vehicle but my VW.

I'd think a pressure system would be more immune than gravity fed.

The CAT gage on my Lycoming never gets within a large margin of the yellow
zone and even in Canada along side the lakes with temps in all ranges from
20 F to 80 F have I ever encountered any hint of carb ice in my
installation. Now with the metal floats in the carburetors, I can't see how
alcohol would affect that. Some of the O rings in the gascolators and fuel
shut off valves might need changing. I fully expect to lose some power
using Supreme with 10% ethanol, but at price differentials exceeding $1.00/
gal?

Some parts in the carb are aluminum or soldered such as the float
which is two brass shells soldered together.

I'm going to get some 10% Ethanol Supreme and put one of my A/C quality
fuel lines in it and let it soak.

It takes time. You might run several years without problems. My Deb
has bladder tanks (Neoprene impregnated canvas I believe) they would
not stand up. The tip tanks are bare fiberglass and resin. They too
dislike Alcohol.

However the big Continental needs 100 octane.

Thanks again for the link. BTW are you going to Oshkosh this year? We will
be covering the helicopters down at the Ultralite runway again.
Stu

Roger (K8RI) ARRL Life Member
N833R (World's oldest Debonair)
www.rogerhalstead.com