Interesting, I never even considered hot/cold plugs. I'll definitely look into it. I run the engine between 5,000 and 5,600 RPM always as the prop reduction unit is 2.4-to-1, the prop is only spinning at 2,500 when the engine is at 6,000 RPM
The motor is not rebuilt yet. It has about 600 hours on it and it maintained to a much higher standard than when in a car. Compression tests are performed yearly and compared for the life of the engine. Every other oil change has an oil analysis performed and every oil change the filter is cut open to check for metal and contamination.
I recently replaced the water pump, thermostat, oil pump (bad seal w/slight leak, replaced the whole thing) timing belt, cam seal, tensioner, etc.
Temps are about 190-200 on the ground. In flight 180-190. I was having some after-boil issues, so switched to Evans NPG+. Valves are due for an adjustment, its been about 12 months since they were last addressed.