Piper Commanche vs Money 201

Pirep:

Went flying yesterday and tried LOP again in my Bulldog
(Lycoming IO-360, standard FIs). Seemed to work ok.
Needed a fair bit higher MP to maintain the speed, but the
CHT (only one) was much lower than "normal". However
one thing I found was that the fuel burn for the same speed
didn't seem any lower, and was possibly a bit higher than
what I normally fly. I fly on pretty low power anyway usually
so I lean until the power starts reducing then bring it back a
shade. Probably the max-power setting, though only at about
50% power or so.

Paul

On Thu, 27 Nov 2003 18:34:09 -0000, "Paul Sengupta"
wrote:

Pirep:

Went flying yesterday and tried LOP again in my Bulldog
(Lycoming IO-360, standard FIs). Seemed to work ok.
Needed a fair bit higher MP to maintain the speed, but the
CHT (only one) was much lower than "normal". However
one thing I found was that the fuel burn for the same speed
didn't seem any lower, and was possibly a bit higher than
what I normally fly. I fly on pretty low power anyway usually
so I lean until the power starts reducing then bring it back a
shade. Probably the max-power setting, though only at about
50% power or so.

Paul


I, too, have a Lycoming IO360 with standard FI's.

If I lean relatively slowly, I find that my airspeed doesn't drop off until
I am 25-50° LOP. If I then enrichen a bit, I'm still LOP.

If I lean very, very slowly, I will see the airspeed drop off sooner.

Could it be that your "normal" procedure leads to LOP settings?



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

"Ron Rosenfeld" wrote in message
news
I, too, have a Lycoming IO360 with standard FI's.

If I lean relatively slowly, I find that my airspeed doesn't drop off
until
I am 25-50° LOP. If I then enrichen a bit, I'm still LOP.

If I lean very, very slowly, I will see the airspeed drop off sooner.

Could it be that your "normal" procedure leads to LOP settings?

Ah, interesting Ron. Since I don't have any EGT sensors and
only one CHT, this may well be the case. By leaning more I
managed to bring the CHT down, I don't know if that means
anything. The "normal" CHT is still down from a full power full
rich climb (I'd expect it would be!).

If I am going somewhere I use more power, maybe 65-75%
but I use a higher fuel flow by flying richer comparatively than
I do when I'm pottering around. The CHT in this case seems to
be exactly the same.

I will have to try leaning to LOP on higher power, but since I don't
have an analyser to see what's going on I'm a bit reluctant. I take the
view that at less than 65% power I can't screw it up whatever I do
with leaning.

Paul

Paul Sengupta wrote:

I will have to try leaning to LOP on higher power, but since I don't
have an analyser to see what's going on I'm a bit reluctant. I take the
view that at less than 65% power I can't screw it up whatever I do
with leaning.

Note that running a little rich at 75% power will be far, far worse than
running a little lean -- you'll have to be running *very* rich to have any
safety margin, since the hottest CHTs come on the rich side.


All the best,


David

On Fri, 28 Nov 2003 13:17:38 -0000, "Paul Sengupta"
wrote:

I will have to try leaning to LOP on higher power, but since I don't
have an analyser to see what's going on I'm a bit reluctant. I take the
view that at less than 65% power I can't screw it up whatever I do
with leaning.

Paul,

Since you don't have EGT sensors, based on my experience with
multi-cylinder sensors and several Lyc IO360 engines, I am virtually
certain that you are running LOP with your method, unless your injectors
are way off.

But there are only a few points that can give you a clue.

In my experience with this engine, when I get to about 50° LOP, my IAS will
have dropped 8 knots or so (and CHT's will also come down after a while).
At peak IAS for the power setting, you will be comfortably ROP, and not in
the 25°-50° ROP "danger zone".

On my engines, if I lean slowly to roughness, and then enrichen just a bit
(as Lycoming recommends!), I will be well LOP.

HTH,

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

"Dan Luke" wrote in message
...
I like ROP for the
power...

Then why did you buy the Gamis?

...and because gas is cheaper then cylinders.

The setting you use, peak power, is the worst of all for cylinder stress
and produces the very highest CHTs.
--

That's what I was thinking, Dan.

My understanding of "everything else" and GAMIjectors is that you run normal
stuff 50-100 degrees, well rich, of peak, to avoid excess heat and
detonation, or you do "the big pull" on the mixture, as the GAMI-types call
it, to get the mixture quickly past the danger zone around peak EGT, then
run GAMIs LOP and get the benefits of cooler temps and fuel economy at
little loss of performance or efficiency.

"A tiny bit ROP" scares the hell out of me, especially now that my Comanche
260 is having a fresh Mattituck overhaul installed. I'll surely not run it
like that.

"CriticalMass" wrote:
"A tiny bit ROP" scares the hell out of me, especially now that my
Comanche 260 is having a fresh Mattituck overhaul installed. I'll
surely not run it like that.

What's your plan for break-in?
--
Dan
C172RG at BFM

But, as he said, "gas is cheaper than cylinders"...until you have to replace them :~)
"CriticalMass" wrote in message ...

"Dan Luke" wrote in message ...
I like ROP for the
power...

Then why did you buy the Gamis?

...and because gas is cheaper then cylinders.

The setting you use, peak power, is the worst of all for cylinder stress
and produces the very highest CHTs.

"Dan Luke" wrote in message
...

What's your plan for break-in?
--

Basically, I plan to cruise around 100-125 degrees ROP at around 75 percent
power, never baby it, always keeping a eye on the GEM.

My IA tells me Mattituck provided some guidelines with the engine when it
came back, and I haven't had the opportunity to review those yet. But the
main things are to keep the power up, temps down (or at least, normal), and
keep the mineral oil in there till consumption stabilizes or after.

I should have said "especially when you have to replace them".
"Tom S." wrote in message ...
But, as he said, "gas is cheaper than cylinders"...until you have to replace them :~)
"CriticalMass" wrote in message ...

"Dan Luke" wrote in message ...
I like ROP for the
power...

Then why did you buy the Gamis?

...and because gas is cheaper then cylinders.

The setting you use, peak power, is the worst of all for cylinder stress
and produces the very highest CHTs.