Piper Commanche vs Money 201

"Ron Rosenfeld" wrote in message
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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)