Engine mixture guidelines

Lean the mixture until it peaks and then enrichen it
(turn it back in) until it drops 50°C.

Not necessary the best advice.

Remember FULL rich for takeoffs and landings unless your flying at
Leadville, CO or some other really high altitude airport.

That is actually VERY BAD and DANGEROUS advice! You will need to lean
for take-off at density altitudes of 3000 feet or above for max power.
Actual airport elevation is irrelevant in this discussion, density
altitude is all that matters.

--
Thomas Borchert (EDDH)

Mxsmanic,

t does indeed stall the
engines in the Dreamfleet Baron model I fly in simulation.


Engines don't stall. Airplanes do.

--
Thomas Borchert (EDDH)

Mxsmanic,

Thanks! Is the stated rule that mixture should be adjusted to just
short of maximum EGT pretty reliable under all circumstances?


No. It's a very bad rule, actually. Go find more info on leaning on the
net, and you'll see.

--
Thomas Borchert (EDDH)

Newps,

No. Lean above 5000 as a general rule.


I would say 3000. But that's pretty much a matter of taste. What's
important is: we're talking density altitude!

--
Thomas Borchert (EDDH)

That is too much anyway, 50 C is 90 F, really 25 C is more
than enough.



"Thomas Borchert" wrote in
message ...
| Lean the mixture until it peaks and then enrichen it
| (turn it back in) until it drops 50°C.
|
| Not necessary the best advice.
|
| Remember FULL rich for takeoffs and landings unless your
flying at
| Leadville, CO or some other really high altitude
airport.
|
| That is actually VERY BAD and DANGEROUS advice! You will
need to lean
| for take-off at density altitudes of 3000 feet or above
for max power.
| Actual airport elevation is irrelevant in this discussion,
density
| altitude is all that matters.
|
| --
| Thomas Borchert (EDDH)
|

Jim,

That is too much anyway, 50 C is 90 F, really 25 C is more
than enough.


That will put you right at the point of maximum internal combustion
pressure (and mostly maximum CHT). Is that good for the engine? I doubt
it.

--
Thomas Borchert (EDDH)

"Newps" wrote in message
...


Matt Barrow wrote:
"Michael Rhodes" wrote in message
...


Never heard of running LOP at 65% power.


And you probably won't unless the engine is turbo'ed.

Why not? I run LOP at 75% with my IO-520.

I didn't say definitely not, just _probably_ not.

Where does the average pilot (or even the vast majority) run the engine?

What damages the engine is excess oxygen and any combustion
temperature. Any mixture with a temperature drop means that
there is excess fuel. 25 C is easy to see on the gauge and
with a single probe assures that all cylinders are rich of
peak. A multi-probe system is best as is fuel injection.

At cruise power settings, you can lean aggressively. But
only the pressure wave of detonation will damage the
combustion chamber.



--
James H. Macklin
ATP,CFI,A&P

"Thomas Borchert" wrote in
message ...
| Jim,
|
| That is too much anyway, 50 C is 90 F, really 25 C is
more
| than enough.
|
|
| That will put you right at the point of maximum internal
combustion
| pressure (and mostly maximum CHT). Is that good for the
engine? I doubt
| it.
|
| --
| Thomas Borchert (EDDH)
|

Matt,


I didn't say definitely not, just _probably_ not.


I still don't get it. Why "probably not"?

--
Thomas Borchert (EDDH)

Jim,

What damages the engine is excess oxygen and any combustion
temperature.

I would want some kind of proof before buying any part of that
sentence. LOP operation is used with great success.

Any mixture with a temperature drop means that
there is excess fuel.

Nope. Search for "lean of peak" operation.


But
only the pressure wave of detonation will damage the
combustion chamber.

Hmm. I'm not sure the engine experts agree.

--
Thomas Borchert (EDDH)