" Spark plug erosion and top of piston erosion show definite signs of = detonation but additionally I look at the bearing area of the connecting = rod and the back side of the rod bearing for black carbon streaks. This = also indicates that detonation has taken place. This may come in handy = when looking at a customer's engine that you have not had 1st hand = exposure to. cb "It's interesting to note that the Lancairs, and the IV-Ps in = particular, tend to run hot. The baffling isn't as good as it could be. = Running a CHT 50 degrees cooler buys you about 5 octane points of = detonation margin. THAT is not an insignificant thing." Actually....in my opinion, that is a huge thing. When you have time, = please send a personal e-mail relative to your Advanced Pilot Seminars. = I've followed the ADA cooling exchange with great interest. cb Craig Berland IV-P ------=_NextPart_000_0176_01C4D180.847F70A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Walter,

Thanks for the feedback.

"Aircraft Turbo charged engines will not detonate if they are = conforming=20 engines and are run on conforming fuel unless the pilot pulls a stupid = pilot=20 trick with the mixture! <g> "

Spark plug erosion and top of piston = erosion show=20 definite signs of detonation but additionally I look at the bearing area = of the=20 connecting rod and the back side of the rod bearing for black carbon=20 streaks. This also indicates that detonation has taken = place. This=20 may come in handy when looking at a customer's engine that you have not=20 had 1st hand exposure to. cb

"It's interesting to note that the Lancairs, and the IV-Ps in = particular,=20 tend to run hot. The baffling isn't as good as it could be. Running a = CHT 50=20 degrees cooler buys you about 5 octane points of detonation margin. THAT = is not=20 an insignificant thing."

Actually....in my opinion, that is a = huge=20 thing. When you have time, please send a personal e-mail relative = to=20 your Advanced Pilot Seminars. I've followed the ADA=20 cooling exchange with great interest. = cb

Craig Berland

IV-P

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