RE: Engine cooling with cowl aircraft
I use an air dam on my gasoline powered planes. Gassers run a lot hotter, so cooling is CRITICAL if you want your engine to survive more than a few gallons. It works. Check out this cowl on my 75cc Extra. The lip goes around 3 sides. I didn't make it - came from the factory like this. But it's not just for looks. It's a functional air dam to draw air out of the cowl. The louvers on the side are cut and functional as well.