I would rather call it vacuum cooling, because the air is drawn through the fins by the low pressure begind it.
I received an engine for evaluation, together with plane pictures. These show the desastrous effect of the standard cooling rule.
Oil Castrol TTS, it helped to let the piston survive this ordeal save for a few light scratches
Spark plug dark brown, proof of excellent carb tuning.
Piston top carbon is ash gray, piston inner side black, just short of "death ash"
The cylinder max temperature was gray, corresponding too 400°C!! Needless to say, this engine did not make it past the 2 gallon mark.
Interesting to see is the bleaching of the anodize of the head. This is caused by heat above 180°C, before the steel will start to turn yellow at about 200°C