Aluminum heads with a low compression 440 will loose compression? Huh?

also most of the heat loss from the chamber is caused by vapourising the incoming charge.

running lean means less of the charge being liquid particless hence less heat loss and a very hot motor or burnt piston

latent heat of vapourisation is key to the survival of the motor

if you run on vapour you melt your motor. as stated elsewhere it needs to be a mixture of air and small liquid particles right up to the back of the inlet valve to pack in enough energy.
once in there, vapourisation of the liquid fuel particles cools the chamber
when you vapourise something it sucks in heat the temperature of its surroundings stays the same or decreases as that heat is sucked in by the change of state liquid-gas.

the coolant just maintains an average temperature around the chamber. If the matcerial of the chamber is a better conductor then anything hot in there, has the heat energy it contains transfered to the coolant a bit quicker.