On Sat, 22 Nov 2003 16:10:07 -0800, Jeff wrote:

The gamiJectors say you can run lean of peak, but when I tried it, I seemed to
lose some airspeed, so I lean to 12 gph which is just a tiny bit ROP, thats
seems to be the best mixture setting for me.

Jeff,

I don't have GAMIJECTORS but have read quite a bit about them. So let me
say the following but, by all means, check with Braley or someone you
respect as knowledgeable.

By running LOP you are running more efficiently -- by that I mean you
produce more HP per unit of fuel consumed. However, as you have noted,
leaning the mixture that far will reduce the total power produced, and you
will certainly see a drop in airspeed.

If by "running a tiny bit ROP" you mean in the range of 25-50° ROP EGT,
that is a baaad place to run an engine. CHT's are higher, and cylinder
pressures are also higher than at other settings. IF you are going to run
ROP, you should try to run around 100-125° ROP.

An alternate method of maintaining the increased BSFC, lower temperatures,
and lower cylinder pressures you obtain by running LOP EGT, if possible
with your setup, would be to, for example, set your power to 65%; lean to
25-50° LOP EGT; and then, instead of using the mixture control to get your
12 gph, use your throttle! That regains the power you lost while
maintaining the benefits of running LOP! You might find you need less than
12 gph to regain your lost airspeed. (GAMI should have a multiplier for
the fuel flow in your engine which you can use to determine HP from fuel
flow).


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