Gasahol Update

Sport Pilot wrote:

You got that backward, if the alcohol is present the water level will
drop, not rise.

No, he got it exactly right. The alcohol will come out of solution with the
gasoline and mix with the water. The effect is that it appears that the water
level rises.

http://www.eaa.org/education/fuel/knopp_alcohol.html

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:

No, he got it exactly right. The alcohol will come out of solution with
the gasoline and mix with the water. The effect is that it appears that
the water level rises.

The explanation is pretty simple. In un-scientific words:

- Water and gas don't mix.
- Alcohol mixes with both water and gas.
- Given the choice, alcohol prefers water over gas.

Stefan

Hmm,
But water will mix into a mixture of gas and alcohol. Maybe that
only works with less water or it takes some agitation. This is how gas
deicer works. The alcohol melts the ice and allows the water to
desolve into the gas alcohol mixture.

In rec.aviation.owning Sport Pilot wrote:
Hmm,
But water will mix into a mixture of gas and alcohol. Maybe that
only works with less water or it takes some agitation. This is how gas
deicer works. The alcohol melts the ice and allows the water to
desolve into the gas alcohol mixture.

But what?

Water is only very slightly soluable in gasoline; basically not at all.

Water is totally soluable in alcohol.

Alcohol is moderately soluable in gasoline, that is, up to a limit.

Where is the confusion?

--
Jim Pennino

Remove .spam.sux to reply.

wrote:
In rec.aviation.owning Sport Pilot wrote:
Hmm,
But water will mix into a mixture of gas and alcohol. Maybe that
only works with less water or it takes some agitation. This is how gas
deicer works. The alcohol melts the ice and allows the water to
desolve into the gas alcohol mixture.

But what?

Water is only very slightly soluable in gasoline; basically not at all.

Water is totally soluable in alcohol.

Alcohol is moderately soluable in gasoline, that is, up to a limit.

Where is the confusion?

--
Jim Pennino

Remove .spam.sux to reply.

Alcohol is completly soluable in gasoline, in fact adding a small
amount of gasoline to model airplane fuel is sometimes done to improve
starting and increase engine heat during the winter. The confusion is
that you can also mix water gas and alcohol and have the three
completely disolve. So why didn't the water disolve into the gas and
alcohol mixture?

Has anybody verfied that this method works all the time? I have a
hunch the rusults can vary depending on vibration and temperature.

But the basic fundamental questions remains despite the discussion of how
much water will dissolve the alcohol on the head of a pin...

The EAA STC says that there can be NO alcohol in the gasoline (and that is
theoretically impossible -- PPB will always be there)

but

The EAA web page gives instructions on gasahol up to 5% alcohol and how to
safely burn it.


Doesn't anybody get the contradiction and what it might mean to the real
world -- especially in California where the state mandates 5.x% in the
gasoline, no more and no less?

Jim

RST Engineering wrote:

The EAA web page gives instructions on gasahol up to 5% alcohol and how to
safely burn it.

Which page? The EAA page I read states "DO NOT FLY" (caps in original) with over
1% alky. In fact, you posted a copy of that page.

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.

Read it again, George. Here you go:


a.. If fuel contains up to 5% alcohol, caution must be exercised. Do not
permit it to remain in tanks or fuel system more than 24 hours, then drain
and refill with alcohol-free fuel, ensuring that no alcohol concentration
remains in fuel lines or sump. Vapor lock may be a problem. DO NOT FLY.

a.. If alcohol content is more than 5%, DO NOT FLY. Drain fuel system, flush
all parts, replace with clean alcohol-free fuel and run up engine long
enough to exchange fuel in carburetor bowl.


a.. What you say is true...as far as it goes. What the first paragraph
IMPLIES is that there IS a safe way to fly with alcohol between 1 and 5%.
In fact, they even give guidelines for it (use caution, 24 hours to use it,
drain the system afterwards, etc.). If you don't want to do this, then DO
NOT FLY.

a.. Or am I reading it wrong?

Jim

a..

a.. Which page? The EAA page I read states "DO NOT FLY" (caps in original)
with over
1% alky. In fact, you posted a copy of that page.

RST Engineering wrote:

a.. Or am I reading it wrong?

In my opinion, you are. I read that to mean that you don't fly the plane with
more than 1% alcohol in the gas.

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.

"RST Engineering" wrote in message

a.. What you say is true...as far as it goes. What the first paragraph
IMPLIES is that there IS a safe way to fly with alcohol between 1 and 5%.
In fact, they even give guidelines for it (use caution, 24 hours to use
it,
drain the system afterwards, etc.). If you don't want to do this, then DO
NOT FLY.

a.. Or am I reading it wrong?\

That is about as poorly worded as anything I haave ever seen. My take on it
is that you should not fly with up to 5%, but you don't have to do something
to the fuel system for up to 24 hours. If you have more than 5%, you have
to act immediately, and take extreme actions in protecting your fuel system,
or your plane is screwed.

But in the long run, the only one who knows for sure is the person that
wrote that piece of work.
--
Jim in NC