On Nov 30, 3:43 pm, Matt Whiting wrote:
Really?

http://www.zenoswarbirdvideos.com/P-51_Variants.html

Seems like water cooling has been around just a little longer than that.

Matt

Much, much longer than that. Here's a quote from
http://www.allstar.fiu.edu/AERO/Propulsion1.htm

"The problem involving water cooled engines is the excess
drag and weight that would be added to the plane thereby having a
significant influence in aircraft performance. By 1908 this
degradation of aircraft performance due to liquid-cooled systems was
noticed and air-cooled engines were first introduced. The savings in
weight were substantial. The air-cooled engine weight (on average) was
between 30% and 40% of the weight of the liquid-cooled engine."