Gordon,
At the shop we have seen the results of up to 10% ethanol in MOGAS.
I did a paper on the pros and cons of MOGAS vs AVGAS. See my website:
www.customflightcreations.com/sitebuildercontent/sitebuilderfiles/ethanol.pdf
Effects ethanol on the Europa are summarized and editorialized below:
The fuel tank is unaffected by ethanol (or alcohol) of any type. The
"plastic tanks" are not as prone to water condensation as metal tanks are.
Note: Ethanol absorbs water, so read below.
The fuel filler neck (that 57 degree black rubber hose between the tank and
the FS18 cobra neck inlet tube) tends to harden with ethanol laced fuel when
the tank is filled well into the neck. It also tends to stink. Using 2
inch aluminum pipe bent or welded to the proper angle and trimmed close the
the plastic tank and FS18, cures this.
The Red stripped fuel hose used on the fuel tank bosses are fine, especially
if you change the hoses every 5 years anyway. When installed properly, the
hose doesn't contact the fuel. I've been known to use ProSeal 890 to seal
the aluminum to tank boss gap then put the hose on to assure a good seal.
The Redux used to secure the coarse screens in the tank fuel fittings tends
to get brittle with exposure to ethanol. About the 10 year point or so it's
really crumbly. It may be a good idea on the 5 year hose change to pull
these fittings and inspect /replace the Redux. Since ethanol laced fuel
cannot be used in ANY fiberglass tank (epoxy or polyester) that problem
should be expected. Pro Seal (PPG 890) fuel sealant will soften with
ethanol but holds up well with up to 10 percent ethanol.
Fuel delivery lines should be of the newer SAE J30 R-9 or better. In the
US, the EPA carb fuel lines (now a SAE J30 R 14 or better (incorporates a
synthetic flourelastomer liner) have proven to be quite reliable. The fuel
hose has an inner liner and a normal outer rubber with fiber reinforcement
in the rubber section and works well on barbed fittings. The fuel smell
does not permeate these lines. Caution, do not over tighten these lines
with your hose clamps.
The braided fuel hose sold by Aeroquip is not double lined and tends to
permeate the smell through the lines over time, but I only use them in the
mono wheel well, and have no smell problems with the MOGAS as the wheel well
is ventilated. Everywhere else in the mono, I use an SAE J30 R-14 line.
IF USING MOGAS WITH AEROQUIP RUBBER LINES, change them at 5 years as
although they seem fine with ethanol up to 10%, they do harden over time.
Teflon fuel lines are fine, but know your fuel line. PTFE fuel lines crack
just like the tank does with flexing. Do not bend them beyond their radius.
Use only proper fittings, and in our experience, these lines take a set
after a few years. If removed and bent from their original shape during
re-installation, test them as they do crack easily if flexed. Nothing lasts
forever, so I tend not to use these lines as they are expensive to purchase
and make, and over time have proven to be fragile...
The fuel pumps are OK as the Facet pumps for the 912 Series can handle up to
10% ethanol. The Piersburgs fail about every 5-7 years in some way so I
can't verify the 914 pumps over time.
The Rotax engine and its components is fine with fuel with up to 10%
ethanol. Mechanics have concerns about flying with ethanol of 10% due to
vaporization. Read on below.
Many have commented on and shared their own experiences with ethanol laced
fuel in the past. Do your research. My clients get shown a video we did on
ethanol effects on a 914 and its tank from an aircraft that sat for six
months with a half a tank of MOGAS with 10% ethanol gas. It is sobering.
Here are the problems I have experienced:
Ethanol laced fuel should not be stored in the aircraft for any longer than
30 days. Especially if in low temp high humidity conditions such as winter.
Water condenses in the fuel over time and once the ethanol reaches water
saturation, a layer of nasty scum forms in the water on the bottom of the
tank. This is some sort of fungus by the looks of it and quite tough to
clean out.
Even if the aircraft was properly decommissioned at the end of the flying
season, pull the carb float bowls, clean them, re-commission the engine and
prep for startup.
Ethanol fuel will also affect the oil so be sure to put new oil in at the
end of the season, fog the cylinders and turn the engine over to keep the
gears and cylinders coated.
When in doubt or buying a used aircraft, fuel lines which do not meet the
current fuel permeation standards tend not to leak but do allow the fuel
scent to permeate through the lines and smell up the aircraft (so you think
you have a leak) and are brittle or cracked on the ends, so do yourself a
favor and replace them.
Rotax 91X engines:
Ethanol will corrode the carb bowls if the fuel is left to sit for a few
months (many manufacturers say degradation begins in less than 30 days).
The aluminum coating in the float bowls actually flakes off the bottom.
This particulate causes premature wear in the main and needle jets and can
clog the jets.
The 912S and 914, with the higher octane rating requirements, are fine with
fresh MOGAS fuel. However, six month old premium fuel in Florida or wet
climates will absorb water, to saturation and will lower the ethanol content
and octane. I have never had a problem with detonation or pinging at high
power after the aircraft has set in the hanger up to 30 days. Plugs look
good over 50 hours of engine operation at cruise operation and local flying.
(Sorry, but I change plugs every annual and typically average only 50 to 100
hours per year, and since plugs are cheap, I don't clean them.)
Flying with fresh ethanol MOGAS has not been a problem. Up to 10K we have
had no problems with vaporization, detonation or misfires over various power
settings ranging from max power down to 65% power. Some reliable sources
have commented that after landing on a cross country fuel stop, fuel
vaporization has prevented engine start. I have not had the problem as we
properly shield and run our fuel lines clear of heat sources and always use
fresh fuel. We do Young Eagle orientation flights and have found on hot
summer days, engine restarts between two and three flights have been problem
free.
Bottom line is, don't leave ethanol laced fuel in the system over a month
(my opinion) and if the plane is to be stored for any length of time (over
30 days), use a fuel stabilizer and run it through the engine to assure the
fuel additive fills the float bowls. Even if the aircraft was properly
decommissioned at the end of the flying season, pull the carb float bowls,
clean them, re-commission the engine and prep for startup. Drain the
MOGAS and refill with fresh fuel.
OR, drain or burn off the ethanol MOGAS and fill completely with 100LL
AVGAS. It is fairly easy to just use AVGAS in your last couple of tanks of
the year then ad a fuel stabilizer if you like, and put the covers on the
plane until flying again. Some aviation fuel suppliers say that 100LL does
lose some of its lead and should not be used if stagnant in the tanks for a
year, but Shell Aviation experts says properly stored and free of water,
AVGAS lasts for years with no degradation.
I do not use ethanol fuel in my 914 any longer as our local MOGAS fuel
suppliers can only supply 92 octane, and can't guarantee it being that high
after only a short period of time. I do not leave even AVGAS in my tank for
over six months without pumping out a large amount to assure the bottom of
the tank, filters and float bowls are clean, and the fuel has the right
color, odor and cleanliness. I change oil every 25 hours with AVGAS and use
a fuel additive (Decalin) to keep the lead in suspension. Works Great. The
fuel price difference and extra oil cost is made back in consistent engine
operation and piece of mind.
Best Regards,
Bud Yerly
Custom Flight Creations, Inc.
--------------------------------------------------
From: "GBWFH2010" <gaxuk2001@gmail.com>
Sent: Wednesday, November 26, 2014 6:38 PM
Subject: Europa-List: Europa fuel system - is it suitable for MOGAS with
ethanol?
>
> It is getting difficult to obtain ethanol-free MOGAS in the UK. Given that
> Rotax equipped microlights in the UK have been operating using MOGAS
> containing ethanol for several years, seemingly without incident, the
> indications are the CAA/LAA may be willing to grant dispensation for
> ethanol based fuel on a type by type basis.
>
> We know the Rotax 912 is approved for up to 10% ethanol and the fuel pipes
> and connectors in our Europas are the same as many microlights, so in
> theory these would appear to be suitable, but my question is does anybody
> know if the Europa fuel tank is ethanol resistant? If it is we may be able
> to get clearance to operate on MOGAS with ethanol.
>
> Of course whenever possible it would always be preferable to use ethanol
> free fuel, but it would be good to have the flexibility to operate legally
> on MOGAS with ethanol when necessary.
>
> --------
> Gordon Grant
>
> G-BWFH
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=434794#434794
>
>
>
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