MoGas Long Term Test: 5000 gallons and counting...

Huh??? On my 230 hp O-470, I cruise at 23-squared, without any fancy
engine monitors. Using the "pull-until-it-feels-about-right" method of
leaning, I get 12 gph.

I can lean to that fuel flow without any undue engine sounds, too. But my
EGTs go well over 1500 degrees, and my CHTs push 350 when I do.

I would rather burn a bit more gas.

On a side note, as I asked you earlier, what part # spark plugs are you
running? I am curious due to your undue propensity to fouling while
running avgas.

I have no idea, and I don't have my logs handy. However, as I said, I will
be replacing them with a hotter-burning plug when they wear out.

Of course, without all that lead fouling, they may never wear out!

;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jim Carriere wrote:

Awww, anecdotal evidence. Statistically speaking, you need a larger
sample size

Actually would be more like a longitudinal case study... same subject
evaluated over a long period of time. Applicable only to the individual,
or perhaps a population of similar subjects... but still a valid data point.

I like the bit about the hours/years on the spark plug...

Dave

"Jay Honeck" wrote in message
news:shJfe.64410$r53.14308@attbi_s21...
On a side note, as I asked you earlier, what part # spark plugs are you
running? I am curious due to your undue propensity to fouling while
running avgas.

I have no idea, and I don't have my logs handy. However, as I said, I
will
be replacing them with a hotter-burning plug when they wear out.

Of course, without all that lead fouling, they may never wear out!

And I've never had a fouled plug (at all...nada) in the 1400 hours I've had
my airplane, burning nothing but 100LL (TN IO-550). Maybe you're just
unlucky :~)

"Jay Honeck" writes:

Huh??? On my 230 hp O-470, I cruise at 23-squared, without any fancy
engine monitors. Using the "pull-until-it-feels-about-right" method of
leaning, I get 12 gph.

I can lean to that fuel flow without any undue engine sounds, too. But my
EGTs go well over 1500 degrees, and my CHTs push 350 when I do.
I would rather burn a bit more gas. [...]

OK, but that brings into doubt your assertion about your fueling style
being a big cost savings, doesn't it? Using 25% more fuel at 70% of
the cost per unit volume is only about a 10% savings. Or maybe you
didn't lean aggressively on avgas either?

- FChE

I can lean to that fuel flow without any undue engine sounds, too.
But my
EGTs go well over 1500 degrees, and my CHTs push 350 when I do.
I would rather burn a bit more gas. [...]

OK, but that brings into doubt your assertion about your fueling
style
being a big cost savings, doesn't it? Using 25% more fuel at 70% of
the cost per unit volume is only about a 10% savings. Or maybe you
didn't lean aggressively on avgas either?

Right -- I leaned no differently with avgas. A cooler running engine
will, all other things being equal, last longer.

I *can* lean a lot more, push my EGTs over 1500 degrees, push my CHTs
to 350+ degrees, save some gas -- and risk my new engine.

Now, of course, there are many theories on leaning (I've read 'em all),
but with my normally aspirated engine having such (relatively)
unbalanced fuel flow to each cylinder, I don't feel comfortable
aggressively leaning.

If I had fuel injected, balanced-flow GAMI-jectors, I'd be singing a
different tune.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:



At cruise we
tend to run 23 squared, leaned back to 15 gph.

????? No wonder you got fouled plugs. You should be around 13 gph at
23 squared for a 230 hp engine.

Jay Honeck wrote:

Huh??? On my 230 hp O-470, I cruise at 23-squared, without any fancy
engine monitors. Using the "pull-until-it-feels-about-right" method of
leaning, I get 12 gph.


I can lean to that fuel flow without any undue engine sounds, too. But my
EGTs go well over 1500 degrees, and my CHTs push 350 when I do.

EGT is irrelavant and 350 is not hot.

On 9 May 2005 10:21:51 -0700, "Jay Honeck" wrote:

I *can* lean a lot more, push my EGTs over 1500 degrees, push my CHTs
to 350+ degrees, save some gas -- and risk my new engine.

Now, of course, there are many theories on leaning (I've read 'em all),
but with my normally aspirated engine having such (relatively)
unbalanced fuel flow to each cylinder, I don't feel comfortable
aggressively leaning.

John Deakin has written that if you lean to the lean side of peak and
the engine runs rough, pulling on full carb heat will distribute the
fuel into the air mixture better and give you the ability to lean to
the lean side of peak.

You might just try it, if only for a little bit if you are too
uncomfortable with the process.

Corky Scott

Jay,

Have you run 93 octane?


Trip

In article y6zfe.67777$WI3.10767@attbi_s71, says...

Yesterday I noticed that we had pumped more than 5000 gallons of mogas
through the Mighty Grape. This represents something like 60 complete fills
(our plane has four gas tanks, totaling 84 gallons), and around 350 hours of
flight time over the last 2.5 years.

(See: http://alexisparkinn.com/fuel_truck.htm for details on our Jim
Weir-inspired fuel truck, the "Mighty Grape"...)

At an average saving of over $1 per gallon (at the moment, it's more like
$1.25), we have paid for the truck (which we use extensively at the hotel),
the tank & pump installation (which has worked flawlessly from "Day One") --
and put aside over $2500 toward our next overhaul.

Best of all, Atlas (our Lycoming O-540-powered Cherokee Pathfinder) simply
runs best on regular, 87-octane unleaded car gasoline. In fact, the ONLY
time we've had trouble with our new engine has been when we were forced to
buy 100LL avgas, which causes lead-fouling of our spark plugs at the drop of
a hat.

All the worries that people stated, both personally and here in this forum,
have turned out to be entirely baseless. After flying with mogas for the
last 2.5 years, I can unequivocally state the following:

1. Mogas works better in my plane than avgas. Our engine runs noticeably
better on mogas.
2. I have had no problems with contamination of any kind (my pump/tank
installation has a very good filtration system)
3. If we've run across any ethanol, the engine has never burped because of
it.
4. We've run mogas from sea level to 13,500 feet, in temperatures from -15
to +97 degrees Fahrenheit, without problem.

Because of this, I state further that:

1. I would burn mogas in my plane even if it cost MORE than avgas -- it runs
that much better.
2. I will never buy a plane that doesn't have the auto gas STC.

The autogas STC is undoubtedly the best thing that has ever happened to
aircraft owners. If you've got the STC, but aren't using it, you are
literally flushing thousands of dollars down the toilet.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Corky Scott wrote:

John Deakin has written that if you lean to the lean side of peak and
the engine runs rough, pulling on full carb heat will distribute the
fuel into the air mixture better and give you the ability to lean to
the lean side of peak.

You might just try it, if only for a little bit if you are too
uncomfortable with the process.


Doesn't always work. I tried it on the O-360 in my Cherokee and the
carb heat made no difference. It still stumbled right after peaking.
Induction systems are different from plane to plane and even from year
to year on the same model. The carb heat trick does work on certain
planes that I fly, so I think it's worth a try. Just don't get your
hopes up.

John Galban=====N4BQ (PA28-180)