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

Fat Albert the Apache dines on a diet of the cheapest, stinkiest,
crapola, 83 octane, gas I can find... He only gets toxic, lead spewing,
plug fouling, valve sticking, 100LL, on trips where I can't get to the
gas station....

My mechanic is mumbling because the plugs have gone 4 years and way
over 400 hours and are going strong... This annual he said he HAD to
change the plugs because of the hours, he felt he JUST couldn't sign
them off for another year... I said, "Fine, JUST as long as you are
paying for them!"... He changed the subject...


I lean by the EGT at 70% or higher... On local flights I am normally at
60 - 65% power, lean em until they go rough, and smile...

ymmv, sar, bni

denny

wrote in message
news:_CBfe.4084$nX1.2291@trnddc09...

On 8-May-2005, "BTIZ" wrote:

BTW, how many out there are aware that 80 octane unleaded avgas used
to
be available, back in the 40s and 50s?

Actually I think it was available up into the mid to late 70s...

80/88, and it was colored Red...


80/87 avgas was (is) NOT unleaded. It just has less lead content than
even
"low lead" 100 (100LL) and WAY less than "conventional" 100 octane (which
you never see anymore).

The specification for red 80 octane did include the option for no lead to be
added. We had it at the airport until about a year ago.

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