wrote:
: Basically, I'm talking about two slight variations on the general rule is that
: max power possible in a non-turbo plane is 75% at 8000'. The first is that I'm
: running a fixed-pitch prop, so I don't have independent control over the prop speed.
: The second is that the 75%@8000' number is at best power mixture setting... 50 ROP.
: At peak/LOP, box the torque from the engine decreases (less power per bang), *and* the
: propeller slows down (less bangs/time). I'd say probably about 5% each for both
: issues... so I can't run 65% at above 7000-8000'. The corollary to that is that above
: 7000-8000', I can do *anything* to the red knob and not hurt anything.

OK, I see now. I agree that once over 7500' you need WOT and peak power EGT
to get any useful power out of the engine. At lower altitudes you can use LOP
techniques because its possible to add MP back to minimize the power losses
caused by LOP operations. With a turbo, presumably it is possible to add back
MP up to a much higher altitude, which is what Deakin is always talking about.

I almost always fly at 70% power when it is available, leaned to "a little
richer than shaking". Without EGT/CHT instruments, it's the best that I can
do. I use 9.5 GPH with my technique, so I am running a bit richer than I
should be for 70% power. I get the grey dust on the bottom of the plane
behind the exhaust stacks, so I am close to the optimum mixture anyway.
--
Aaron C.