MoGas Long Term Test: 5000 gallons and counting...

We can find airports that carry mogas that meet the STC requirements with no
problems. Unfortunately, none of them are in California. The closest one
to me is just east of Salt Lake. Die Governator has decreed that all
gasoline shall be contaminated with 5.5% alcohol before it leaves the
refinery. He didn't make any exceptions for old farm vehicles, lawnmowers,
weedwhackers, or aircraft -- all of which to one degree or another get
honked up with alcohol.

The one thing that keeps burning in the back of my head is that they
probably soaked some of these carb seals in pure alcohol for six months and
said, "look, they swell up" and thus forbade gasahol. My sense, and it is
only a gut feeling, is that if you ran your airplane for a couple of days on
gasahol then let it sit for a couple of weeks in 100LL that you wouldn't see
any deterioration at all. However, you are in direct violation of the STC
if you do so.

It might be nice to have EAA and/or Petersen do the same seal test with 1%
gasahol, 2% gasahol and so on over a short, moderate, and long time to see
the exact problems facing us. Whether we like it or not, gasahol is with us
to stay, at least in California.

Jim


"Dave Stadt" wrote in message
. ..

You should be able to find airports that carry mogas that meets the STC
requirements.

The Governor of MN just signed us up for 20% alcohol over the next few
years. Soon we'll be able to drink the stuff......

There is a range and max power output penalty for use of alcohol since
it has only about half the energy density of pure hydrocarbon fuel.

("nrp" wrote)
The Governor of MN just signed us up for 20% alcohol over the next few
years. Soon we'll be able to drink the stuff......


Yup. In Minnesota we've been at 10% ethanol blend for many years. 20% is now
heading down the pipe, into our tanks. I've rebuilt a few lawn mower carbs
because of that darn ethanol.

http://www.msra.com/NonOxygenatedFue...st08.16.04.pdf
Non-Oxygenated (Ethanol-Free) fuel availability in MN

Minnesota Street Rod Association's list
http://www.msra.com/

3 gas stations in St. Paul, MN (300,000 pop.)
3 gas stations in Minneapolis, MN (400,000 pop.)
About 50 gas stations throughout the Twin Cities Metro Area (3.5 million
people)

ALL of the other stations are what we call "outstate." (1 million people)

I was down in Iowa last week. There, stations carry both good gas and the
ethanol junk - your choice. In Minnesota, in the Twin Cities anyway, 95% of
all gas stations sell ONLY the 10% (soon to be 20%) ethanol blend.

North Dakota has consumer choice at the pump - like Iowa. In years of
driving to Minot, ND (510 miles one way) we've noticed at least 10%
improvement in gas mileage with good gas (non-oxygenated) vs. our usual Twin
Cities 10% ethanol blend. I think the mileage improvement has been closer to
15%!! ...which is 40-60 miles every 400.


Montblack

nrp wrote:
The Governor of MN just signed us up for 20% alcohol over the next few
years. Soon we'll be able to drink the stuff......

There is a range and max power output penalty for use of alcohol since
it has only about half the energy density of pure hydrocarbon fuel.


It's worse than that, nrp.

Alcohol is hygroscopic. It's going to suck all the water out of the air
that it can, basically destroying that tightly controlled combustion
even there in the cylinder. Someone needs to tell the politicians
pushing the farms subsidies that "wet wood don't burn good"

--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."

In rec.aviation.owning nrp wrote:
: There is a range and max power output penalty for use of alcohol since
: it has only about half the energy density of pure hydrocarbon fuel.

Actually, it's about 10% less than that of gasoline IIRC. For automotive
uses, the compression ratio of the engine can be increased to get some of that back,
since the alcohol has a higher octane rating.

-Cory
--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

In rec.aviation.owning wrote:
: Actually, it's about 10% less than that of gasoline IIRC. For automotive
: uses, the compression ratio of the engine can be increased to get some of that back,
: since the alcohol has a higher octane rating.

: -Cory
: --

I looked into it briefly again today and feel the need to correct myself.
Apparently, the specific energy density of pure ethanol is about 60-70% that of
gasoline. Raising the CR to compensate yields the 10% less range I've heard quoted.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

: It might be nice to have EAA and/or Petersen do the same seal test with 1%
: gasahol, 2% gasahol and so on over a short, moderate, and long time to see
: the exact problems facing us. Whether we like it or not, gasahol is with us
: to stay, at least in California.

From what I've read, it's more than just seals in the fuel system. The
alcohol can attack aluminum fuel tanks, IIRC.

-Cory

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

wrote:

From what I've read, it's more than just seals in the fuel system. The
alcohol can attack aluminum fuel tanks, IIRC.

Anybody had mogas issues with fiberglass wing tanks?

From what I've read, it's more than just seals in the fuel system. The
alcohol can attack aluminum fuel tanks, IIRC.

Anybody had mogas issues with fiberglass wing tanks?

I've got fiberglass tip tanks.

No problems.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"