Patent ID: 8646421

Claim:
An internal combustion engine comprising: four cylinders each having a respective piston positioned therein and connected with a crankshaft for movement in the respective cylinder according to a four-stroke cycle having an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke; each cylinder having a plurality of ports with a plurality of valves openable and closable to control fluid flow into and out of the cylinder through the ports; wherein combustion occurs in a first two ( 18 B, 18 C) of the four cylinders ( 18 A, 18 B, 18 C, 18 D) that are each operatively interconnected in fluid flow communication between a second two ( 18 A, 18 D) of the four cylinders via respective passages (P 1 , P 2 , P 3 , P 4 ) connecting respective ones of the ports of the respective cylinders, each such passage connecting only two of the four cylinders; a controller ( 19 ) operatively connected to the plurality of valves (V 1 i , V 1 e , V 2 a , V 2 b , V 3 a , V 3 b , V 4 a , V 4 b , V 5 a , V 5 b , V 6 e , V 6 i ) and configured to open and close different ones of the valves such that fluid directed from the first two ( 18 B, 18 C) of the four cylinders to the second two ( 18 A, 18 D) of the four cylinders via the respective passages (P 2 , P 4 ) after combustion in the first two ( 18 B, 18 C) of the four cylinders is redirected via the passages (P 1 , P 3 ) from the second two ( 18 A, 18 D) of the four cylinders to the first two ( 18 B, 18 C) of the four cylinders after the respective exhaust strokes of the second two ( 18 A, 18 D) of the four cylinders.