Originally Posted by Pianorak
The same presumably applies to a M20F.
No, the gear doors of the M20F aren't as close to the ground. The F isn't quite as aerodynamically tidy as the J and part of that is that the gear doors weren't as tight fitting.
Originally Posted by IO540
I wonder why your LOP figures are so much slower. The fuel flow doesn't have to be that much lower. There is no efficiency gain in going that far LOP. The tiniest amount past peak EGT is every bit as good. Perhaps you cruise at 75% or higher power.
In part that's a factor of me not liking to run at the higher EGTs you get just LOP. If I do run LOP, it tends to be at least 25 LOP, which is the setting that was giving the figures I quoted earlier, so that I'm not cooking the valves. I understand the theory and know that at FL100 I can run at peak EGT, I just don't feel comfortable doing so.
Although LOP does give lower CHTs, they're never that high to begin with. At 100 ROP the hottest cylinder never goes above 360F, which is fine. At 25 LOP the CHT falls to around 290F. And LOP does give lower fuel burn, but again it's not that high to begin with, so the saving in relation to the speed loss doesn't seem worth it.
The late Roy LoPresti who designed the M20J had a motto - "Life is short - Fly
FAST!" It seems disrespectful to his memory to fly a Mooney at anything less than full chat.