Piper Commanche vs Money 201

because I dont want to kill the engine.
when you lean that much and dont get any engine roughness, my common
sense (and knowing my airplane) tells me thats more then plenty.

I was leaning by tempeture today and 12 gph was right at 100 degrees ROP



Dan Luke wrote:

"Jeff" wrote:
I have leaned it to 8 gph and the engine was still running fine,
but that just seems to much.

Why?
--
Dan
C172RG at BFM

it peaks at about 10-10.5 gph
today I took my time, after it peaked, I noted the temp, then increased the richness about
100 degrees, which put me at 12-12.2 gph



Ron Rosenfeld wrote:

On Sun, 23 Nov 2003 08:49:28 -0800, Jeff wrote:

what makes me nervous is that the engine does not get rough, I was assuming due to the
gami's, so I am not sure where the cut off point would be. I have leaned it to 8 gph and
the engine was still running fine, but that just seems to much

How many degrees LOP are you at 8 or 9 gph?

Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

with as many types of planes out there as there are, there is no telling, asking
someone to guess the type of plane you have is about the same as asking someone to
guess your social security number.

I havnt seen any get the book number either, but you get pretty close if you
subtract 10 kts from what they say they will do. Excxeption is Cirrus, people who
own them tend to say they get pretty much what the book says they will get.

Stu Gotts wrote:

Which kind to you think?

I've yet to see the majority of planes get the book numbers, so I'd
say that's a bit aggressive.

On Sun, 23 Nov 2003 18:45:14 -0800, Jeff wrote:

it peaks at about 10-10.5 gph
today I took my time, after it peaked, I noted the temp, then increased the richness about
100 degrees, which put me at 12-12.2 gph




Well, 100° ROP *is* in a safe area so far as CHT is concerned. But you'd
still reduce your peak cylinder pressures by 7-8% by running the same HP at
50° LOP. This will result in less stresses on your engine.

And your BSFC will be improved, also, leading to decreased fuel consumption
for the same HP generated.

Perhaps as you gain more experience with the GAMI's, you'll feel more
comfortable running LOP. I don't believe that running 50° LOP EGT with a
smooth engine puts you in any risk of getting so lean that the engine might
stop.

However, even if you choose to keep things ROP, you'll still show some
improvement in fuel consumption due to the more balanced fuel flows.

Best wishes,

Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

see this is what confuses me, if you run LOP, lose some HP, then add MP to regain the lost HP,
are'nt you still putting the same stress on the engine?
I have been running the gami's for about 8 months now.

Ron Rosenfeld wrote:


Well, 100° ROP *is* in a safe area so far as CHT is concerned. But you'd
still reduce your peak cylinder pressures by 7-8% by running the same HP at
50° LOP. This will result in less stresses on your engine.

And your BSFC will be improved, also, leading to decreased fuel consumption
for the same HP generated.

Perhaps as you gain more experience with the GAMI's, you'll feel more
comfortable running LOP. I don't believe that running 50° LOP EGT with a
smooth engine puts you in any risk of getting so lean that the engine might
stop.

However, even if you choose to keep things ROP, you'll still show some
improvement in fuel consumption due to the more balanced fuel flows.

Best wishes,

Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

On Sun, 23 Nov 2003 20:57:28 -0800, Jeff wrote:

see this is what confuses me, if you run LOP, lose some HP, then add MP to regain the lost HP,
are'nt you still putting the same stress on the engine?
I have been running the gami's for about 8 months now

Engine stress is not solely a matter of HP generated.

The reason you are NOT putting the same stresses on the engine is because
in the LOP regime, cylinder peak pressures are less (for the same HP
generated). CHT is also less.

The reason cylinder peak pressures are less is because the rate of burn of
the fuel charge is slower.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

When you say "kill the eingine" do you mean have it stop running or break
it?

Mike
MU-2


"Jeff" wrote in message
...
because I dont want to kill the engine.
when you lean that much and dont get any engine roughness, my common
sense (and knowing my airplane) tells me thats more then plenty.

I was leaning by tempeture today and 12 gph was right at 100 degrees ROP



Dan Luke wrote:

"Jeff" wrote:
I have leaned it to 8 gph and the engine was still running fine,
but that just seems to much.

Why?
--
Dan
C172RG at BFM

What kind of stress are you talking about? Engines experience themal stress
and mechanical stress. Both are lower when running the same power LOP.

Mike
MU-2


"Jeff" wrote in message
...
see this is what confuses me, if you run LOP, lose some HP, then add MP to
regain the lost HP,
are'nt you still putting the same stress on the engine?
I have been running the gami's for about 8 months now.

Ron Rosenfeld wrote:


Well, 100° ROP *is* in a safe area so far as CHT is concerned. But
you'd
still reduce your peak cylinder pressures by 7-8% by running the same HP
at
50° LOP. This will result in less stresses on your engine.

And your BSFC will be improved, also, leading to decreased fuel
consumption
for the same HP generated.

Perhaps as you gain more experience with the GAMI's, you'll feel more
comfortable running LOP. I don't believe that running 50° LOP EGT with
a
smooth engine puts you in any risk of getting so lean that the engine
might
stop.

However, even if you choose to keep things ROP, you'll still show some
improvement in fuel consumption due to the more balanced fuel flows.

Best wishes,

Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

"O. Sami Saydjari" wrote in message ...
I am looking at buying one of two planes: a 1978 Mooney M20J or a 1965
Piper Commanche PA-24-260.
(3) I heard Mooney is teetering on bankruptcy. Is this a real big
downside?

So what? Piper has already been there. Take the Mooney, it is newer,faster
and more efficient.

"Jeff" wrote in message
...
see this is what confuses me, if you run LOP, lose some HP, then add MP to
regain the lost HP,
are'nt you still putting the same stress on the engine?
I have been running the gami's for about 8 months now.


Don't confuse cylinder pressures (also addressed in Deakin's articles) with
the stress of HEAT, particularly in CHT.