What effect does high power with a lean mixture have on engine temperature?

High power with a lean mixture can lead to overheating in an aircraft engine. When the mixture is leaned, there is less fuel relative to the amount of air entering the engine. While this can improve fuel efficiency and allow for a more complete burn of fuel, it also means that less fuel is available to absorb and dissipate heat generated during combustion.

At high power settings, the engine produces a significant amount of heat. If the mixture is leaned excessively, especially under high power conditions, the result can be increased combustion temperatures, leading to higher engine operating temperatures. This situation can cause damage to the engine components if not managed properly, as the engine may run too hot, potentially resulting in issues such as damage to the cylinder heads or piston overheating.

A balanced and well-managed mixture is critical in ensuring that the engine operates within its optimal temperature range. Thus, while a lean mixture might initially seem beneficial for efficiency, it can be detrimental to engine health when combined with high power settings.