Some video of a Lenape radial powered Cub being flown... 50 HP and three cylinders.
https://www.youtube.com/watch?v=Ft6FVrnOPsM
You have to hand prop it, but apparently not from particular position. That aside I've always thought the Cub setup for hand propping, behind with hand near throttle, is a great design. Especially so with a muffled (quiet) A65 engine, or the like.