Yesterday Flight Club showed you a bunch of cool large-scale R/C aircraft, but all of the piston-powered ones for the most part had single or twin-cylinder engines carefully disguised by cowling or engine covers. This WWII F4F Wildcat model, however, has a more authentic 5-cylinder radial engine, which at that scale is a pretty neat accomplishment by itself. The guy even flies the engine bare to show it off (during a testing flight).
Also check out this scale model of a Lockheed XH-51 with asymmetric ducted fan propulsion:
And finally this scale model of an apparently real ring-winged airplane: