Leaning Procedure for a Carbureted 182

Jeffrey,

Typical cruise power setting is 20"
manifold pressure 2300 RPM.

Wow! Why so low?


Can someone please give me the proper leaning procedure for both cruise
flight and ground operations (taxing)?


For taxi: lean right after start-up and stabilized RPM very aggresively
until a slight rise in RPM occurs. If you lean any further, the engine
should quit. The RPM rise should be around 25 RPM. If it is higher, have
your idle mixture adjusted. If you advance the throttle for the mag check,
the engine will stumble because it is so lean. That's GOOD because it
reminds you to enrichen again for take-off power. You cannot hurt the
engine by leaning at taxi power.

For flight: Lean whenever the power is below 75 percent. Lean until the
first cylinder peaks (that's not identical with the cylinder having the
highest EGT, it is the first cylinder whose EGT goes down again during
leaning). Then leave the mixture there if the engine runs smoothly or
enrichen until abojut 100 F rich of peak.

Have you read John Deakin's columns on engine management at www.avweb.com?

--
Thomas Borchert (EDDH)

One reason and one reason only. With anything but a direct headwind, this
will get the fuel consumption down below 10 gallons of $3.50 fuel an hour.

Jim
20" and 2200.


"Thomas Borchert" wrote in message
...
Jeffrey,

Typical cruise power setting is 20"
manifold pressure 2300 RPM.

Wow! Why so low?

RST,

One reason and one reason only. With anything but a direct headwind, this
will get the fuel consumption down below 10 gallons of $3.50 fuel an hour.

Jim
20" and 2200.


If it's any help, I'm paying 7.75. However, your trip time will be much
longer. You'll reach hour-based maintenance intervals sooner, too. Are you
sure you're saving money on this?

--
Thomas Borchert (EDDH)

Hi Thomas;

Well I didn't think it was too low a power setting. What do you prefer to
use?

As for Deakin's articles, I've not read them, thanks for the tip on that!
But which one should I start on?

Thanks again for the input!
Jeffrey

"Thomas Borchert" wrote in message
...
Jeffrey,

Typical cruise power setting is 20"
manifold pressure 2300 RPM.

Wow! Why so low?


Can someone please give me the proper leaning procedure for both cruise
flight and ground operations (taxing)?


For taxi: lean right after start-up and stabilized RPM very aggresively
until a slight rise in RPM occurs. If you lean any further, the engine
should quit. The RPM rise should be around 25 RPM. If it is higher, have
your idle mixture adjusted. If you advance the throttle for the mag check,
the engine will stumble because it is so lean. That's GOOD because it
reminds you to enrichen again for take-off power. You cannot hurt the
engine by leaning at taxi power.

For flight: Lean whenever the power is below 75 percent. Lean until the
first cylinder peaks (that's not identical with the cylinder having the
highest EGT, it is the first cylinder whose EGT goes down again during
leaning). Then leave the mixture there if the engine runs smoothly or
enrichen until abojut 100 F rich of peak.

Have you read John Deakin's columns on engine management at www.avweb.com?

--
Thomas Borchert (EDDH)

Jeffrey,

Well I didn't think it was too low a power setting. What do you prefer to
use?

75 percent as long as it's available, all that's there when not. And yes, it
could be too low a power setting influencing the scavenging process through
lower temps and pressures. But the main culprit is likely not enough leaning
on the ground.

As for Deakin's articles, I've not read them, thanks for the tip on that!
But which one should I start on?


There's a trio in succesion dealing with Mixture, Prop and Manifold
Pressure, IIRC. The latter is easy to recognize by its title, which is
"Manifold Pressure Sucks" (get it? - if not, you will after reading).
There's a general one dealing with engine management older than those. These
are the foundation. But basically, you'll be ok if you read all of them in
chronological order. It's a lot to read, but well worth it.

--
Thomas Borchert (EDDH)