Gasahol Update

On Fri, 03 Jun 2005 04:27:28 GMT, George Patterson
wrote:

Casey Wilson wrote:

Sort of..., #'s 1, 3, and 4 don't answer the questions. While #2 seems
to reply by alleging incompatibility, it doesn't state the damage. How are
those components not compatible? Do they explode?

Problems vary depending on the composition of the items. Generally seals,
gaskets, and diaphrams *may* swell and/or soften when exposed to alcohol. This
caused problems with some automobiles when gasohol was introduced in the
mid-70s. I do not reliably remember what substances were most affected

Well I do, I was an auto mechanic with gas started being laced with
alcohol, and saw the results several times.

I'll never forget the first time we got a complaint. They guy had a
midsize Chrysler and brought it in complaining of it not running well.

We got it into the shop and popped the hood. It immediately drew a
crowd, every single mechanic was hanging over the engine compartment
with their mouth's dropped and their eyes wide open in amazement.
Every single hose connected to the fuel system, including vent hoses,
was swelled to twice or three times it's size and was sticky and gooey
to touch.

We realised that this was just the surface. Every diaphram in the
carburator, every rubber piece, would be the same way. The fuel line
from the tank had several hoses also, and they were all shot in the
same way.

And it smelled like alcohol.

It would likely take a mechanic several days to properly replace every
single component that had been affected, and at the time there were no
known compatible substitutes, although they showed up remarkably fast.

So "IF" your airplane does not have hoses compatible with alcohol, or
any component of your fuel system is not compatible with alcohol, this
is what you are facing.

Corky Scott

Corky Scott wrote:
On Fri, 03 Jun 2005 04:27:28 GMT, George Patterson
wrote:

Casey Wilson wrote:

Sort of..., #'s 1, 3, and 4 don't answer the questions. While #2 seems
to reply by alleging incompatibility, it doesn't state the damage. How are
those components not compatible? Do they explode?

Problems vary depending on the composition of the items. Generally seals,
gaskets, and diaphrams *may* swell and/or soften when exposed to alcohol. This
caused problems with some automobiles when gasohol was introduced in the
mid-70s. I do not reliably remember what substances were most affected

Well I do, I was an auto mechanic with gas started being laced with
alcohol, and saw the results several times.

I'll never forget the first time we got a complaint. They guy had a
midsize Chrysler and brought it in complaining of it not running well.

We got it into the shop and popped the hood. It immediately drew a
crowd, every single mechanic was hanging over the engine compartment
with their mouth's dropped and their eyes wide open in amazement.
Every single hose connected to the fuel system, including vent hoses,
was swelled to twice or three times it's size and was sticky and gooey
to touch.

We realised that this was just the surface. Every diaphram in the
carburator, every rubber piece, would be the same way. The fuel line
from the tank had several hoses also, and they were all shot in the
same way.

And it smelled like alcohol.

It would likely take a mechanic several days to properly replace every
single component that had been affected, and at the time there were no
known compatible substitutes, although they showed up remarkably fast.

So "IF" your airplane does not have hoses compatible with alcohol, or
any component of your fuel system is not compatible with alcohol, this
is what you are facing.

Corky Scott

Sounds like a problem with an additive to me. Some of the early octane
boosters were alcohol mixed with toulene and acetone. I think Wenn's
or STP or some company got a class action suit over this. BTW the
toulend in 100 LL melted the plastic floats put in a lot of planes made
for 80 avgas. You won't smell a small quantity pure ethanol or
methanol, they have very low oders, the alcohol in distilled liquors
smells because of the organic compounds from the fruit, grain, or maybe
the yeast, I cannot remember.

Corky Scott wrote:

Well I do, I was an auto mechanic with gas started being laced with
alcohol, and saw the results several times.

Oh, I saw the results. What I meant was that I do not remember what it was in
those hoses and such that was affected by exposure to alcohol.

One of my friends was a line mechanic for an Oldmobile dealer. His stories were
similar to yours. I happened to own a Ford during that period, and my only
problems involved hoses in the fuel system. Our other car was an Opel, but it
would only run on Amoco high test, so we never had an alcohol-related problem
with it.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.

Sport Pilot wrote:

You won't smell a small quantity pure ethanol or
methanol, they have very low oders, the alcohol in distilled liquors
smells because of the organic compounds from the fruit, grain, or maybe
the yeast, I cannot remember.

First off, we're not talking about a small quantity here; we're talking about
nearly 10% of the fuel. That means several gallons, at a minimum, and that's
just for one tank of gas. Secondly, the alcohol used in the 70's was ethanol
made from corn; a distilled liquor. In essence, pure grain alcohol. It stinks
(as any old fratrat can tell you).

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.

On model airplanes using methanol based fuel, they use silicone fuel
tubing. With gas engines you use tygon or neoprene tubing. The
alcohol will make those tubings harden and crack withen a few weeks.
But not the swelling and turning to liquid. That has to be from a more
active solvent such as toulene or acetone.

Sport Pilot wrote:
On model airplanes using methanol based fuel, they use silicone fuel
tubing. With gas engines you use tygon or neoprene tubing. The
alcohol will make those tubings harden and crack withen a few weeks.
But not the swelling and turning to liquid. That has to be from a more
active solvent such as toulene or acetone.

Not so. I never used any additives in my cars, and I had problems with softening
and swelling of the hoses in the fuel system of my van. Besides, the gas in
Georgia and Tennessee (where I lived at the time) was cut with ethanol, not
methanol.

This was a very definite, well-documented problem at the time, and no amount of
theory based argument is going to change that fact.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.

George Patterson wrote:
Sport Pilot wrote:
On model airplanes using methanol based fuel, they use silicone fuel
tubing. With gas engines you use tygon or neoprene tubing. The
alcohol will make those tubings harden and crack withen a few weeks.
But not the swelling and turning to liquid. That has to be from a more
active solvent such as toulene or acetone.

Not so. I never used any additives in my cars, and I had problems with softening
and swelling of the hoses in the fuel system of my van. Besides, the gas in
Georgia and Tennessee (where I lived at the time) was cut with ethanol, not
methanol.

This was a very definite, well-documented problem at the time, and no amount of
theory based argument is going to change that fact.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.

I understand that ethanol has the same effect on the hoses. In those
days a lot of the hoses were part natural rubber, or some cheaper
grade. Have you noticed that the hoses today seem to last longer then
they did before with the leaded fuels? When they took the lead out
they added toulene to the fuel, this would attack those cheaper hoses,
today the hoses are made to take the toulene and ethanol.

I agree it does no damage to the mechanical and valve portions of the
engine.

According to Marks Engr Handbook, the heating value of an equal mass of
10% ethanol gasahol is 96.1% of an equal mass of gasoline (I used
Hexane as an approximation to gasoline & assumed ethanol). Here in MN
the car mileage reduction is generally assumed to be about 5%. I see
that in the differences between Wisconsin gasoline vs Minnesota gasahol
in my vehicles.

Since the fuel mass flow in an aircraft carb isn't likely to change
significantly, and since the engine is a heat engine, with all other
things being equal, a power reduction is to be expected. Other items
such as compression ratio, timing, mixture proportions etc could be
varied to optimize the use of gasahol, but the heat value just isn't
there.

Who knows what the seals etc used in an aircraft are - except that
there are a lot of legal reasons that they are not being updated in
contrast to technical reasons why they should be updated. Actually a
simple aircraft engine has few seals as you know, and if the float
(let's see we're back to metal again aren't we) don't sink, and the tip
of the needle doesn't dissolve, we are back to mostly static seals in
the fuel selector etc. I don't know about fuel cell bladders, except
that given the regulatory climate, there is a good chance they have not
been updated for 50 years either.

I just had the seals go and the idle jet varnish over in my '87 Yamaha
M/C carb, and lawn mowers here routinely need carb work.

Vapor pressure is primarily determined by fuel temperature, although a
standard temperature is used for the Reid vapor pressure test. But
that standard temp has to be held very closely to make equivalent fuel
evaluations. In practical service the significance of the temperature
variation seems to never be addressed. For example, where is it
written that you can't paint your wings black? A chem prof once noted
that the vapor pressure typically doubles every 15 deg F.

I have to agree that only in a most marginal situation (probably
aggravated by the need for a fuel pump) might ethanol (b.p. = 172 deg
F) or especially methanol (b.p. = 148 deg F) put you over the edge into
trouble. My original response was hearsay.

The long term storage issue - the weed whip (manual) I just bought says
to throw away all ethanol laced gasoline after 60 days.

I agree booze keeps a lot better but that is primarily an alcohol/water
& flavor mix which does not seem to be subject to deterioration (maybe
shrinkage?) of alcohol hydroicarbon mixes.

Old sour gas is a problem here in MN. It seems to be aggravated by
higher fuel storage temperatures. My small-engine repairman neighbor
confirms this (as well as the rampant carb problems).

You would have more power from ethanol if you richen up the mixture.
But I doubt less than 5% ethanol is enough to matter either way.

("nrp" wrote)
[snip]
The long term storage issue - the weed whip (manual) I just bought says
to throw away all ethanol laced gasoline after 60 days.

I agree booze keeps a lot better but that is primarily an alcohol/water
& flavor mix which does not seem to be subject to deterioration (maybe
shrinkage?) of alcohol hydroicarbon mixes.

Old sour gas is a problem here in MN. It seems to be aggravated by
higher fuel storage temperatures. My small-engine repairman neighbor
confirms this (as well as the rampant carb problems).


Gas going bad:
I wonder if ethanol blended gasoline in the 1950's would last just as long
as regular 1950's gasoline? Years?

Non-ethanol choices in the (50 miles x 50 miles) Twin Cities Metro area are
limited, to say the least. You really have to hunt for those few stations
that sell non-oxy gas ...and then it's usually premium!! NoDak - pumps have
options. Iowa - pumps have options. Twin Cities - no options.

http://www.msra.com/NonOxygenatedFue...st08.16.04.pdf)
"These are the stations that provide non-oxygenated (ethanol-free) gasoline
in the state of Minnesota and Wisconsin. Please stop by and thank them for
their participation during cruising season, continue to patronize them with
your daily drivers and remind them that our collector cars count on them for
the non-oxygenated fuel."

Twin Cities is maybe 40 of those stations. Duluth has more stations listed
than Mpls and St Paul ...combined.

20% ethanol is heading down the pipe.


Montblack
2 lawnmower carbs rebuilt.
1988 55hp Suzuki (3 cyl) outboard motor on the family fishing boat has 3
carbs on it - yikes.