Patent ID: 8397693
Filing Date: 2013-03-19
Classification: F02D,Y02T

Abstract:
1. An engine assembly comprising: an engine structure defining a combustion chamber and a first port in communication with the combustion chamber; a piston located within the combustion chamber and reciprocally displaceable from a top dead center position to a bottom dead center position during an intake stroke and displaceable from the bottom dead center position to the top dead center position during a compression stroke immediately subsequent the intake stroke; a first valve supported by the engine structure and selectively opening and closing the first port; and a first valve actuation assembly engaged with the first valve and operable in first and second modes, the first valve actuation assembly operated in the first mode when fuel is provided to the combustion chamber and operated in the second mode when fuel is cutoff from the combustion chamber while the piston reciprocates between the top dead center position and the bottom dead center position during a fuel cutoff condition comprising one of fuel cutoff during electric operation of a hybrid vehicle that includes the engine assembly and deactivation of less than all cylinders of the engine assembly, the first mode providing a first opening duration of the first valve during one of the intake stroke and the compression stroke and the second mode providing a second opening duration of the first valve during the one of the intake stroke and the compression stroke that is different than the first opening duration to reduce vacuum in the combustion chamber.