Patent ID: 7021277

Claim:
Method of operating a four-stroke internal combustion engine during part load operation, said engine including a variable volume combustion chamber defined by a piston reciprocating within a cylinder between top-dead center and bottom-dead center points, intake and exhaust passages, and intake and exhaust valves controlled during repetitive, sequential exhaust, intake, compression and expansion strokes of said piston comprising: trapping and re-compressing combusted gases in the combustion chamber when engine operation is below a predetermined part load operating point effective to provide elevated combustion chamber temperature and pressure conditions; establishing recirculated combusted gases within the combustion chamber during intake strokes when engine operation is above said predetermined part load operating point; supplying at least a portion of a total combustion cycle fuel requirement into said elevated combustion chamber temperature and pressure conditions when engine operation is below said predetermined part load operating point; and supplying the total combustion cycle fuel requirement during the intake stroke when engine operation above said predetermined part load operating point.