The 7500 ft density altitude should help cool your engine, because unless it is turbocharged, it won't be able to generate full hp. As you ascend in altitude, your engine produces less hp, right? Mike Busch (SavvyAviation) has some lectures on engine leaning-ROP-LOP etc. He says the worst cht to operate at is, I think, 40 to 50 degrees ROP. This is where the most pressure and heat are generated in a normally aspirated engine. I'm no expert, but it is quite interesting to hear what Mr. Busch has to say. https://www.youtube.com/watch?v=X-tKyiUZ3ts&t=3344s
Re cooling effect at altitude:
Thermal conduction of air decreases with altitude, at about the same rate engine performance decreases.
Both effects are the result of fewer air molecules available for a given volume, In spite of standard temperature lapse, an engine running at sea level will experience similar CHT’s at 12,000’ - at same power setting and fuel mixture ratio. Running ROP & LOP to manage temps is another topic and does not address the underlying problem.
Engine/cooling/installation should provide for manageable temps under normal operating conditions, It’s no fun flying behind a hot engine, Ive been there, takes alot of fun out of flying.
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