ORIGINAL: skillet92
craigteffe it is mounted to the airframe. As for the heat i would have thought that with the cowl off and the prop pushing air over the head that it would cool fine. The oil is lawnboy ashless at 32-1
There are *tons* of posts through the years about this myth. The head cooling doesn't occur with a prop unless it is moving forward (basically). Sure, there is SOME air going back, but at full bore, or near too it, the engine is generating LOTS more heat than a restrained airframe only with prop airflow can dissipate.
The very best breaking in after that "initial" tweaking run on the ground, occurs in the AIR, with lots of throttle changing, lots of airspeed changing and LOTS of airflow.
Fact.