I read the stuff, but again I am a bit confused as to why you say this. Everything I have read refers to the effect as dimininshing the affect of drag induced by a radiator. Nothing I have seen say it offers thrust which would then equal more speed. Can you please clarify?
Not to be overly simplistic but there are two forces that act along the longitudinal axis of an aircraft, thrust and drag. In level flight, any force which tends to move the aircraft forward is thrust and any that impedes its forward motion is drag, right? The only ways to make any airplane faster is to increase thrust or decrease drag (or both). A good cooling system would be designed for minimum drag and the P51's does this. In addition, the P51 uses the expansion of gas caused by the heat from the radiator to increase the velocity of the air exhausted by the system through a relatively small opening (i.e., a "nozzle") to produce a small amount of thrust. It doesn't offset the entire amount of cooling system drag but it is still a force pushing the aircraft forward, i.e., thrust. So, the P51's system not only reduces net drag but increases net thrust. The net result is increased speed.
