ethanol question

Recently my gas station placed stickers on the pumps warning it could
contain up to 10% ethanol.

My ride is an experimental built in 1997 with a C-85 always run on mogas.

Quick research indicates 3 concerns:
1-loosens debris inside the fuel system affecting filters.
2-mixes more readily with water (hydroscopic) but can experience "phase
separation" during climbs causing water to overload filter/sediment bowls.
3-can deteriorate composites, rubbers and plastics causing leaks/breakages.


Leaning towards more frequent gascolator inspections for 1 and 3, but
unsure on overloading a sediment bowl....

I'm wondering how others are addressing these concerns.

Thanks, Dick

On Thu, 12 Jun 2008 11:46:58 GMT, "Dick" wrote:

Recently my gas station placed stickers on the pumps warning it could
contain up to 10% ethanol.

My ride is an experimental built in 1997 with a C-85 always run on mogas.

Quick research indicates 3 concerns:
1-loosens debris inside the fuel system affecting filters.
2-mixes more readily with water (hydroscopic) but can experience "phase
separation" during climbs causing water to overload filter/sediment bowls.
3-can deteriorate composites, rubbers and plastics causing leaks/breakages.


Leaning towards more frequent gascolator inspections for 1 and 3, but
unsure on overloading a sediment bowl....

I'm wondering how others are addressing these concerns.

Thanks, Dick


for the reasons you mention I run my O-200 on 100/130 avgas with
REM38E plugs.

you have more worries than you've identified.

bacterial contamination that is not often checked for in mogas.
(surface of water stuff)

UV deterioration of the fuel leading to waxy deposits settling out.

a lot of your carby seals are actually leather. add that to your list.

just bye the bye when I pulled apart a marvel schebler carby I was
using, between the inlet filter and the needle seat was a lot of
friable black gunk which is supposedly from mogas that was used
previously. it was causing fuel dribbles after shutdown.

"Dick" wrote in message
news:S084k.10872$kW2.67@trnddc01...
Recently my gas station placed stickers on the pumps warning it could
contain up to 10% ethanol.

My ride is an experimental built in 1997 with a C-85 always run on mogas.

Quick research indicates 3 concerns:
1-loosens debris inside the fuel system affecting filters.
2-mixes more readily with water (hydroscopic) but can experience "phase
separation" during climbs causing water to overload filter/sediment bowls.
3-can deteriorate composites, rubbers and plastics causing
leaks/breakages.


Leaning towards more frequent gascolator inspections for 1 and 3, but
unsure on overloading a sediment bowl....

I'm wondering how others are addressing these concerns.

Thanks, Dick

I am not flying at the present time, and I am really annoyed by the entire
"gasohol" farce.

(Brief Rant)
E-10 is a more expensive product, contains as little as 96 percent of the
energy, is generally regarded as less stable, and is the result of purely
political decisions of questionable merit!
(End of Brief Rant)

OTOH, since it is an experimental and you have been using MoGas all along,
you are more likely to know what materials are in the fuel system--if it was
mine and the problem was the tanks, I would switch immediately to AvGas and
avoid idling with rich mixture during warmup and taxiing.

Some assistance regarding the hoses, seals, and gakets may be as close as:
1) The auto parts store--those guys have been on the "front lines" a lot
longer, or
2) The nearest hose and o-ring suppliers for aircraft--who probably have
product data sheets for what the sell.

This is the first that I remember hearing of "phase separation" which may
just mean that I forgot. However, there is at least one obvious way to
test. Get something that can produce a good suction--a "feeding syringe"
from the nearest feed store might be a good choice. Then, put some E-10
gasohol in a clear glass soda bottle, connect the bottle to the feed syringe
with a sturdy hose (or something similar), pull back on the plunger, and see
what happens. That should give you a way to take your fuel sample from
about sea level to about 18000 feet in a hurry. Obviously, you would need
to add some instruments and test at various temperatures to learn what might
happen over a wide range of temperatures and altitudes; but a lot of us
bloviate a lot on usenet and, with some very simple testing, you should be
able to get an idea of whether the whole discussion really applies to your
application.

Peter

P.S.: A home brew test for the actual presence of ethanol was discussed
on this forum a few months ago.

"Peter Dohm" wrote in message
...
"Dick" wrote in message
...

This is the first that I remember hearing of "phase separation" which may
just mean that I forgot. However, there is at least one obvious way to
...

Phase seperation is when you add water to the gas / ethanol mix and the
ethanol / water seperates out. The ammount of water required to do this
depends on the ethanol concentration and the temperature - so things might
be OK on the ground where it's warm...

The water / ethanol mix will be too "lean" for you engine and the gasoline
left behind will have a lower octane than the gasoline / ethanol blend that
may or may not be adequate for your needs.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"Capt. Geoffrey Thorpe" The Sea Hawk At Wow Way D0t C0m wrote in message
...
"Peter Dohm" wrote in message
...
"Dick" wrote in message
...

This is the first that I remember hearing of "phase separation" which may
just mean that I forgot. However, there is at least one obvious way to
...

Phase seperation is when you add water to the gas / ethanol mix and the
ethanol / water seperates out. The ammount of water required to do this
depends on the ethanol concentration and the temperature - so things might
be OK on the ground where it's warm...

The water / ethanol mix will be too "lean" for you engine and the
gasoline left behind will have a lower octane than the gasoline / ethanol
blend that may or may not be adequate for your needs.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.
I know that I am flagellating a dead horse; but there are a very limited
munber of real solutions, and trying to substitute usenet dialog for the
work and expence of a new STC is simply ot one of the real
solutions--expecially since the percentage of ethanol or other oxiginate is
sure to remain a moving target.

1) Obviously, as already mentioned, you can switch to Avgas.

2) Presumably, with an experimental, you can just assume the risk and
"run watcha brung".

3) As discussed in several previous threads, you can precipitate the
alcohol out of the fuel, separate the remaining water (resulting from the
precipitation process) from the "pute" gasolene, and dispose of the
contaminated alcohol and water mixture which will probably contain too much
water to burn. As you just pointed out, an octane test would then be in
order--although I suspect that the fuel will remain well above the
requirement for a C-85 engine. I also have my doubts whether the resulting
fuel will be below the rating originally shown on the pump--mainly because I
strongly suspect that the ethanol is simply added to the existing fuel on an
"as available" basis.

4) The most correct solution is to recruit enough a sufficient user group
at the airport, and possibly at several nearby airports as well, to
guarrantee sufficient usage justify fuel deliveries to the FBOs and also
stocking of the additional fuel type by those FBOs. Unless there are
currently unused tanks at self service pumps, that would probably also mean
a substantial investment by the user group to purchase the needed equipment
for the FBOs. It is not just that that the FBOs probably can not afford or
justify the expense; but the phrasing of the original post suggests that the
local FBOs are not strangers to the problem of off-airpost price shopping.

IMHO, based on what I have seen and heard in my own local area, solution no.
4 will not happen; solutions 2 and 3 are problematic and probably
unacceptable; and that leaves the switch to AvGas--simply because the users
lack the understanding and resolve to support their FBOs in any other way.

Peter

On Thu, 12 Jun 2008 09:43:50 -0400, "Peter Dohm"
wrote:

"Dick" wrote in message
news:S084k.10872$kW2.67@trnddc01...
Recently my gas station placed stickers on the pumps warning it could
contain up to 10% ethanol.

My ride is an experimental built in 1997 with a C-85 always run on mogas.

Quick research indicates 3 concerns:
1-loosens debris inside the fuel system affecting filters.
2-mixes more readily with water (hydroscopic) but can experience "phase
separation" during climbs causing water to overload filter/sediment bowls.
3-can deteriorate composites, rubbers and plastics causing
leaks/breakages.


Leaning towards more frequent gascolator inspections for 1 and 3, but
unsure on overloading a sediment bowl....

I'm wondering how others are addressing these concerns.

Thanks, Dick

I am not flying at the present time, and I am really annoyed by the entire
"gasohol" farce.

(Brief Rant)
E-10 is a more expensive product, contains as little as 96 percent of the
energy, is generally regarded as less stable, and is the result of purely
political decisions of questionable merit!
(End of Brief Rant)

OTOH, since it is an experimental and you have been using MoGas all along,
you are more likely to know what materials are in the fuel system--if it was
mine and the problem was the tanks, I would switch immediately to AvGas and
avoid idling with rich mixture during warmup and taxiing.

Some assistance regarding the hoses, seals, and gakets may be as close as:
1) The auto parts store--those guys have been on the "front lines" a lot
longer, or
2) The nearest hose and o-ring suppliers for aircraft--who probably have
product data sheets for what the sell.

This is the first that I remember hearing of "phase separation" which may
just mean that I forgot. However, there is at least one obvious way to
test. Get something that can produce a good suction--a "feeding syringe"
from the nearest feed store might be a good choice. Then, put some E-10
gasohol in a clear glass soda bottle, connect the bottle to the feed syringe
with a sturdy hose (or something similar), pull back on the plunger, and see
what happens. That should give you a way to take your fuel sample from
about sea level to about 18000 feet in a hurry. Obviously, you would need
to add some instruments and test at various temperatures to learn what might
happen over a wide range of temperatures and altitudes; but a lot of us
bloviate a lot on usenet and, with some very simple testing, you should be
able to get an idea of whether the whole discussion really applies to your
application.

Peter

P.S.: A home brew test for the actual presence of ethanol was discussed
on this forum a few months ago.

Phase separation is temperature dependent.
If the water content of the fuel is borderline at 70F and you go up
3000 feet the 54F temperature may cause the water and ethanol to drop
out.
** Posted from http://www.teranews.com **

clare at snyder dot ontario dot canada wrote in message
...

Phase separation is temperature dependent.
If the water content of the fuel is borderline at 70F and you go up
3000 feet the 54F temperature may cause the water and ethanol to drop
out.

Why is this not a problem in cars? They can see a considerable temperature
swing between night and day, and I have yet to see a problem caused by ethanol.
(Not to say it has never happened, it is just not on my radar screen. Educate
me.)

Vaughn

On Fri, 13 Jun 2008 10:23:31 GMT, "Vaughn Simon"
wrote:


clare at snyder dot ontario dot canada wrote in message
.. .

Phase separation is temperature dependent.
If the water content of the fuel is borderline at 70F and you go up
3000 feet the 54F temperature may cause the water and ethanol to drop
out.

Why is this not a problem in cars? They can see a considerable temperature
swing between night and day, and I have yet to see a problem caused by ethanol.
(Not to say it has never happened, it is just not on my radar screen. Educate
me.)

Vaughn

It happens.
However, MOST cars on the road today have SEALED fuel systems, so
condensation is not a major issue.
I know of NO aircraft with sealed fuel suystems.

** Posted from http://www.teranews.com **

Perhaps rather than sitting in front of the computer knocking MOGAS
for no longer being a cheap alternative to 100LL, we might actually
start educating ourselves and experimenting on how to make gasahol or
even E85 work in an aircraft. A quick web search turned up this
project: http://www.age85.org/. If there's going to be a new and
viable alternative to 100LL, somebody is going to have to either find
or invent one.

Or you could just learn to hang-glide. (did I say that out loud???)

Harry Frey
gliders n' stuff

clare at snyder dot ontario dot canada wrote in message
...
On Fri, 13 Jun 2008 10:23:31 GMT, "Vaughn Simon"
wrote:
Why is this not a problem in cars? They can see a considerable temperature
swing between night and day, and I have yet to see a problem caused by
ethanol.
(Not to say it has never happened, it is just not on my radar screen. Educate
me.)

My point is that perhaps we need to be learning from taking a long hard look
at our cars. If cars can be made to run reliably on a gas-ethanol blend, than
so can airplanes, I see no big differences. If differences exist, they have
nothing to do with temperature changes at altitude, since cars see similar
temperature swings without apparent problems.

I see no insurmountable difficulties in retrofitting at least many of our
planes to sealed gas caps and installing a different venting system to the tanks
(if that is what it takes). Nothing in aviation is cheap and I don't predict
that this would be, but it may beat being grounded.

Vaughn