ORIGINAL: downunder
Not that it's totally applicable to sports models but some might find it interesting the extent that one guy went to with a pylon engine to get decent cooling.
http://www.supercoolprops.com/articl...ed_cooling.php
Some of the ideas could be a help with even our basic type cowling, especially the bit about a plenum chamber and intake shape.
I have started a rant about cooling at
http://prme.nl/forum/viewtopic.php?t=37 . Experimental baffling pictures of my 35cc test engine included.
So far, it works very well, as could be expected.