More About Leaning During Climb

wrote in news:beeeb3$13o$1
@solaris.cc.vt.edu:

What do you (or anyone else for that matter) think?

Sounds quite reasonable.

The idea of leaning during climb is to keep the mixture about the same,
and the temps in a good operating range - all of which it seems you are
doing.

Max power is about 100 ROP. That is a point where there is still excess
fuel to vaporize for added cylinder pressure, while at the same time
providing cooling. Lots of power, but it wastes fuel and is not a very
clean burn. Contrary to the original post, higher EGT's does NOT equate
to more power - often the contrary. From Best Power the power actually
declines as you approach peak EGT. This point gives you hotest exhaust
gasses (there are some technicalities here I won't bother with at the
moment), and best economy. LOP, we go further down the power curve
(which we can make up for if we still have more throttle available), and
start cooling with excess air instead of excess fuel. Exhaust is
cleanest.

Critical thing to watch is your CHT's. You are dead on as for keeping
them below 400, and lower would be better but may not be an option in
the climb. Technically EGT's on that Seneca can get to 1650 - but any
EGT measurement is guesswork at best and I prefer not to push it.

Look for CHT's down around 400 in the climb, and 350 in cruise, and you
will be in good shape.


-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------