In my mind, the difference in temperature would be so small regarding it's effect on cylinder pressure, it would likely be immeasurable. When the balloon shrinks in the freezer, there is a 30 degree difference at least (my mind is thinking Celsius here), same for the tire. As far as the air gap intake goes, the plenum never gets as hot, so less heat can get transferred into the air as it rushes through. It is likely a measurable difference in plenum temperature between an air gap intake and any other.
The cooling system in the engine should be designed to maintain a steady temperature of all engine components including the heads that have coolant passing through them. Aluminum has the ability to better transfer the temperature spikes than Iron but I can't see it really affecting cylinder pressure because the average temperature would be what is having the most effect here.
That's my non scientific view on the subject from a guy who graduated grade 8 and as has been said before, it's worth what I charged you for it?
Cley
