Patent ID: 8011331

Claim:
A method comprising: operating an engine in an eight-stroke mode including: a first stroke forming an intake stroke and including opening an intake valve via a first peak of a first cam lobe to provide communication between an air source and a combustion chamber formed by an engine structure defining a cylinder bore and a piston disposed within the cylinder bore, the first stroke further including providing a first fuel mass to the combustion chamber; a second stroke immediately subsequent to the first stroke and forming a first compression stroke; a third stroke immediately subsequent to the second stroke and forming a first expansion stroke, the first expansion stroke including a first power stroke where the air-fuel mixture provided in the first stroke is ignited; a fourth stroke immediately subsequent to the third stroke and forming a second compression stroke, the fourth stroke including an exhaust valve in communication with the combustion chamber being in a closed position and preventing discharge of gas from within the combustion chamber when a valve lift mechanism engaged with the exhaust valve is engaged by a second peak of a second cam lobe; a fifth stroke immediately subsequent to the fourth stroke and forming a second expansion stroke, the second expansion stroke including the intake valve being in the closed position when a valve lift mechanism engaged with the intake valve is engaged by the first peak of the first cam lobe; a sixth stroke immediately subsequent to the fifth stroke and forming a third compression stroke, the third compression stroke including the exhaust valve being in the closed position, a second fuel mass being provided to the combustion chamber during the fourth or sixth stroke; a seventh stroke immediately subsequent to the sixth stroke and forming a third expansion stroke, the third expansion stroke including the intake valve being in the closed position; and an eighth stroke immediately subsequent to the seventh stroke, the eighth stroke forming an exhaust stroke and including opening the exhaust valve via the second peak of the second cam lobe.