NACA cowling
Initial versions of the Sportster were powered by a 5-cylinder LeBlond radial engine of 70-85 hp. The third model of the Sportster offered either the Warner Scarab or LeBlond radial engine (renamed as a Ken-Royce engine when Rearwin bought that company). Both produced 90 hp. Initially the engine was left uncovered but Townend rings and a propeller spinner were an option on the Deluxe model; a 1939 redesign introduced the streamlined NACA cowling. Range was about 500 miles for all versions.