An engine includes a housing defining an annular bore and a piston assembly disposed within the annular bore. The engine also includes a rotary valve comprising a circular faceplate and a wall structure disposed at an outer periphery of the faceplate, a portion of the at least one rotary valve disposed within the annular bore, and a rotary drive mechanism connected to the rotary valve and configured to rotate the rotary valve between a first position to align an opening of the wall structure with the annular bore to allow the piston of the piston assembly to travel within the annular bore from a first location relative to the rotary valve to a second location relative to the rotary valve and a second position to define a chamber relative to the piston of the piston assembly at the second location.