Patent ID: 8683987

Claim:
An Otto cycle internal combustion engine ( 12 ) comprising: a pump ( 58 ) comprising an input ( 56 ) and an output ( 62 ); at least two enclosed and individually partitioned dry-sump cylinder crankcases ( 46 , 48 , 50 , 52 ) in pneumatic closed loop connection, each defining an air volume between an underside of a piston ( 18 ), a wall of a cylinder ( 16 ), and a crankshaft bearing support girdle ( 68 ) separating said dry-sump cylinder crankcases ( 46 , 48 , 50 , 52 ) from a wet-sump crankcase ( 38 ); at least two evacuation conduits ( 54 ) in pneumatic series connection with said individually partitioned cylinder crankcases ( 46 , 48 , 50 , 52 ) and with said input ( 56 ); at least two expansion conduits ( 60 ) in pneumatic series connection with said individually partitioned cylinder crankcases ( 46 , 48 , 50 , 52 ) and with said output ( 62 ); at least two synchronized evacuation valves ( 64 ) disposed between said individually partitioned cylinder crankcases ( 46 , 48 , 50 , 52 ) and said evacuation conduits ( 54 ), said evacuation valves ( 64 ) being operable between an open position for allowing air flow from said individually partitioned cylinder crankcases ( 46 , 48 , 50 , 52 ) and into said evacuation conduits ( 54 ) and a closed position for restricting air flow from said individually partitioned cylinder crankcases ( 46 , 48 , 50 , 52 ) and into said evacuation conduits ( 54 ); and at least two synchronized expansion valves ( 66 ) disposed between said individually partitioned cylinder crankcases ( 46 , 48 , 50 , 52 ) and said expansion conduits ( 60 ), said expansion valves ( 66 ) being operable between an open position for allowing air flow into said individually partitioned cylinder crankcases ( 46 , 48 , 50 , 52 ) and a closed position for restricting air flow into said individually partitioned cylinder crankcases ( 46 , 48 , 50 , 52 ); wherein said air volume of the individually partitioned cylinder crankcase ( 46 ) is evacuated by said pump ( 58 ) when said evacuation valve ( 64 ) of said individually partitioned cylinder crankcase ( 46 ) undergoing an intake stroke is open and displaced to the air volume of the individually partitioned cylinder crankcase undergoing an exhaust stroke when said expansion valve ( 66 ) of said individually partitioned cylinder crankcase undergoing the exhaust stroke ( 50 ) is simultaneously open.