Originally Posted by
Lead Balloon
Setting the mixture to around 25C ROP is the worst setting for a piston aero-engine
whatever the power setting. It will produce the highest CHT possible for that power.
Given the choice of a 74% power setting with a CHT of X and a 74% power setting with CHT less than X, I choose the latter.
Detonation is not the only thing that is detrimental to engine longevity. So is heat. The manufacturers say so.
On the attached chart, the CHT does not peak at 25 degrees C ROP.