Patent ID: 7621240

Claim:
An internal combustion engine comprising: at least two cylinders, each of the at least two cylinders having a reciprocating piston and at least one inlet for receiving at least one combustion ingredient; a communication conduit configured to provide selective fluid communication between a first cylinder of the at least two cylinders, and a second cylinder of the at least two cylinders, the communication conduit having a first state where the first cylinder and the second cylinder are in fluid communication and a second state where the first cylinder and the second cylinder are not in fluid communication; and a control system, the control system placing the communication conduit in the first state to provide fluid communication between the first cylinder and the second cylinder during at least a part of an engine operation period starting during a movement of a piston of the first cylinder towards a bottom dead center (BDC) position at a work stroke of the first cylinder and ending during a movement of the first piston away from the bottom dead center (BDC) position, during the engine operation period a piston of the second cylinder moves at least one of towards a bottom dead center (BDC) position and away from the bottom dead center (BDC) position, wherein the engine operation period, during at least a part of which communication is provided by the communication conduit, starts at 100 crankshaft degrees before the bottom dead center (BDC) position of the first piston.