RTK,
Some Interesting links that may be helpful (snatched from my forum):
http://www.rcshowcase.com./html/faq....0is%20cooling?
http://www.liquidcooledairpower.com/lc-longertbo.shtml
http://www.liquidcooledairpower.com/lc-topendheat.shtml
http://naca.larc.nasa.gov/reports/1929/naca-tn-328/
http://naca.larc.nasa.gov/reports/1938/naca-report-612/
http://www.pilotfriend.com/aero_engines/images/j5.jpg
http://www.tpub.com/content/construc.../14264_213.htm
http://www.lnengineering.com/pinz.html

Quote from http://www.allstar.fiu.edu/AERO/Propulsion1.htm
Quote:
Many of the best fighters of World War II were powered by liquid-cooled engines and by the mid-1940s the debate was over and air-cooled engines were the victors. One major development assisting the air-cooled engines was the development of the NACA cowling. This was an enclosure for the engine that limited the flow of air over the engine cylinders to the air actually in contact with the cooling fins of the cylinders. This advanced was very important in improving the efficiency of air-cooled aircrafts