Originally Posted by
James McIlvenny
I'm about four years late, but I can give it a crack.
In my PA31-350 manual (early), it describes in the footnote for the cruise performance chart that at best economy power, power is reduced by 4.5%.
so 60.5% of 350 is 211.75 hp, using 13.5 to find hp
Interesting, have not found any such reference in the newer manual where LOP is prescribed but maybe they were too busy at Piper back then for these little details. Like deleting the climb power leaning chart and replacing it with CLIMB FULL RICH!
We have many more hours on our PA31 nearly all LOP now. Zero issue except if anyone can share their CHT data would much appreciate it. Not sure if it's just ours but both sides CHTs are spread ridiculously - looks like most off the effective cooling air goes past No.6 and leaves Nos.3&4 warmer than they should be. I suspect the cowls were designed for looks back then, scant attention paid to where the air actually goes.