"Cliff" wrote in message
...
Did all P-51s have intercoolers(aftercoolers) and where did the cooling
air
enter the cowling and where was it exhausted?

The original design of the Merlin powered Mustang had an intercooler between
the two stages of the blower and an aftercooler between the final stage and
the carburetor.
The intercooler was later eliminated in favor of a single larger
aftercooler. See the page below, about 3/4 of the way down:

http://nasaui.ited.uidaho.edu/nasasp...rollsroyce.htm