MoGas Tips, Tricks, Concerns, How To

If I have not had too long a taxi, I can wipe the INSIDE of the exhaust
stack on my O-320 with a white handkerchief and get very little
smudging. I've never experienced a rough mag (or sticking valve) in
its 1700 hrs. Spark plugs are cleaned as an annual insp formality.

A solution that might be explored by non-turboed 100LL users is to use
a combination of FADEC and reduce the compression ratio as necessary to
use auto premium, and reduce the gross weight of the aircraft if
necessary to maintain performance.

I have no answer for turboed aircraft except to note that they are used
primarily at higher altitudes where the compression ratio is not a
limiting factor. Intercoolers would be have to be used universally.

Then we would be down to one environmentally tolerable fuel for piston
engines.

"xyzzy" wrote in message
oups.com...

nrp wrote:
The major Mogas concern I have is that so few have endorsed the
concept, that it may not ever get to critical mass. The engine
manufacturers ignore it or don't support it, the AOPA never mentions
it, many FBOs simply state "our insurance won't cover it", the hodge
podge of state gasahol laws are eroding the practicality of it all, and
lastly we owners of low compression engines simply are not using it
anywhere near as much as we should.

Mogas is simply assumed by most "real pilots" and mechanics to be a
substitute fuel, inferior or harmful to engines, and something that is
only used by a small minority of old aircraft owners. For those and
probably still other reasons, mogas isn't widely available for cross
country use. The advantages of Mogas are only talked about in forums
such as these.

Mogas users have to get this situation changed. Some day 100LL is
going to disappear by an EPA mandate & then where will we be? I feel
the 100LL users are whistling in the dark as no substitutes seem to be
forthcoming to their leaded fuel.

Both Aviation Consumer and AOPA pilot have articles on this subject in
their current issues. They both conclude that 100LL is really not
going to be going away in the foreseeable future (the EPA has delegated
the issue the FAA and the FAA is not interested in getting rid of
100LL), and they also both describe research into alternatives that is
in fact going on now.

Somehow I don't believe the oil companies are going to base their business
on what the FAA and AOPA think is going to happen.

"nrp" wrote in message
oups.com...
It seemed as though the AOPA article ignored the proven success of
MoGas, but it did point out the very limited success of 100LL
alternatives. I wonder if there are any more high compression engines
running in test cells trying replacement fuels. It sounded like there
was only one.

GAMI has been running a Lycoming GTSIO-540 on a test stand using rot gut gas
using it's PRISM system without a burp, and hoping for an STC when they can
work out vibration tests.

http://www.gami.com/prism.html

"Jay Honeck" wrote in message
oups.com...
For example in their article on fuel, Aviation Consumer had a sidebar
on mogas saying it wasn't as good as advertised. They said several
shop owners told them that when they get engines or cylinders in for
work, they can immediately tell if the owner is running mogas by the
corroded camshafts and deposits on the valves and seats. These shop
owners claimed that the extra overhaul costs eliminate the mogas
savings, and attribute it to the "varying additives" used in mogas and
to the fact that most mogas sold doens't really meet the ASTM standards
dictated by the STC.

I read that article, and it is the closest thing to total bull**** I've
ever read on the subject. I can line up several shop owners who will
absolutely contradict the statements of those supposed "shop owners".


100 LL has FOUR TIMES the amount of lead that my engine was designed to
run with. As a result, spark plugs foul with lead far easier, making
it necessary to aggressively lean the engine. Which, of course, in
turn leads to much higher exhaust gas temperatures, and unnecessary
wear and tear on the engine.

Now that's bull****. Aggressive leaning is COOLER when done properly (i.e.,
using the proper temp range when LOP. It also produces lower internal
cylinder pressures, more through combustion, lower CHT temps.

100 LL has FOUR TIMES the amount of lead that my engine was designed to
run with. As a result, spark plugs foul with lead far easier, making
it necessary to aggressively lean the engine. Which, of course, in
turn leads to much higher exhaust gas temperatures, and unnecessary
wear and tear on the engine.


Geez Jay, better get yourself educated on leaning. Leaning properly on
the ground means way, way lean of peak which by definition is downright
cold EGT's although on the ground at low power there's no such thing as
high EGT. You need to familiarize yourself with the red box when it
comes to leaning. Done properly the EGT's are as cool or cooler than
rich of peak and the CHT's are significantly cooler. An example is that
about the worst place to run your engine while at 75% would be 60-80
degrees rich of peak.

"nrp" writes:


Mogas users have to get this situation changed. Some day 100LL is
going to disappear by an EPA mandate & then where will we be? I feel
the 100LL users are whistling in the dark as no substitutes seem to be
forthcoming to their leaded fuel.


I have to agree; the refiners want to dump any TEL product; the EPA wants
them to do so; the whole national market is the size of a decimal point
to the distribution side.....


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

Geez Jay, better get yourself educated on leaning. Leaning properly on
the ground means way, way lean of peak which by definition is downright
cold EGT's although on the ground at low power there's no such thing as
high EGT.

Welcome to 1952, where you have to move levers on the panel in order to
make your plane run properly while on the ground. And you say MOGAS is
bad? Strange how I have to do none of that, when I run with mogas.
The engine just purrs like a kitten, without any input from me at all.

Of course it's *possible* to run avgas in my engine with minimal
fouling of the plugs. All I've got to do is pull that red lever back
until the engine coughs and sputters, and then push it in a tiny bit
more. But do you really think that it's better to run an engine with
stuff that REQUIRES such bizarre (outside of the aviation world) engine
management?

How in the world did pilots ever come to accept a fuel that they know
won't run in their engines without aggressive leaning? Can you
imagine selling a fuel like this to car owners?

"Well, sir, this fuel is usable in your car only at speeds of 45 mph
and above. Below that speed, you'll have to pull this little lever out
-- but only until the engine sputters a bit. Then push it back in a
bit, and you SHOULD be okay..."

It would be laughable, if it weren't considered "the norm" by so many
pilots...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:
Now that's bull****. Aggressive leaning is COOLER when done properly (i.e.,
using the proper temp range when LOP. It also produces lower internal
cylinder pressures, more through combustion, lower CHT temps.

Not in a carbureted engine. The fuel flows are simply not matched well
enough between cylinders to run lean of peak without risking damage.

Now, in a fuel-injected engine (especially with GAMI), that's a whole
different world. But in the low compression carbureted world, you run
rich of peak, or you risk destroying your engine.

Again, untrue, Jay.

The Continental E-225 (with a PS5-C carburator) in my Bonanzan runs just fine LOP.
I can't quite get as far LOP as my fuel injected bretheren. About 25-30 degrees
LOP seems to be about as far as it goes. Would you like to see the downloads
from my JPI?

Walter Atkinson (sp?) of GAMI has told me he routinely operated a carbed
Cessna 182 (O-470) LOP. In order for it to be smooth he had to play with the
throttle and carb heat some, though.

Now, if you had said that you can't run a carbed Lycoming engine LOP I might
have given you a bit of slack. I think it still can be done, but I think
its much more difficult.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR

Jay Honeck wrote:
: Now, in a fuel-injected engine (especially with GAMI), that's a whole
: different world. But in the low compression carbureted world, you run
: rich of peak, or you risk destroying your engine.

Sorry Jay, but it's not necessarily so cut-n-dried. Yes, fuel distribution is
rather poor in your flat six. Not quite as bad in my flat four, but I still have
uneven fuel distribution. The real issue is knowing *FOR SURE* what power setting
you are at and never exceeding the POH amount. Lycoming says essentially *ANY*
mixture setting is fine if you stay below 75% and 450 degrees CHT. I personally don't
like to run it that close and use the more conservative 65% and 375 degrees CHT. At
those power settings and temperatures, you cannot damage your engine with the red
knob. You can lean it until it wheezes if the CHT stays cool enough.

Now, whether or not it runs smoothly there is an entirely different matter....
one of vibration acceptability. Having some above peak and some below peak EGT is
fine if you keep the power and temps low enough.

-Cory

--

************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

"Jay Honeck" wrote in message
oups.com...
Geez Jay, better get yourself educated on leaning. Leaning properly on
the ground means way, way lean of peak which by definition is downright
cold EGT's although on the ground at low power there's no such thing as
high EGT.

Welcome to 1952, where you have to move levers on the panel in order to
make your plane run properly while on the ground. And you say MOGAS is
bad? Strange how I have to do none of that, when I run with mogas.
The engine just purrs like a kitten, without any input from me at all.

Nice change of subject when caught with your pants down.