Patent ID: 7426916

Claim:
A method of operating an engine having at least one cylinder including an intake valve and an exhaust valve, the method comprising: injecting a first amount of fuel into the cylinder; auto-igniting a first mixture of air and said first amount of fuel by compressing said first mixture; injecting a second amount of fuel into the cylinder after auto-igniting said first mixture; exhausting a portion of gasses from auto-ignition of said first mixture before combusting said second mixture; varying a timing of exhausting the portion of gasses from auto-ignition of said first mixture to vary a timing of combustion of said second mixture; combusting a second mixture of said second amount of fuel and gasses from auto-ignition of said first mixture; holding an intake valve of the cylinder closed between auto-igniting the first mixture and combusting the second mixture; and exhausting said combusted second mixture.