Patent ID: 7503296

Claim:
An internal combustion engine comprising: a cylinder block defining a plurality of cylinders at least half of said plurality of cylinders being selectively deactivatable by a plurality of switching hydraulic lifters; a source of pressurized oil; at least one solenoid-actuated hydraulic control valve operable to selectively communicate pressurized oil from said source of pressurized oil to actuate said plurality of switching hydraulic lifters thereby deactivating said at least half of said plurality of cylinders; an electronic control unit in electrical communication with said at least one solenoid-actuated hydraulic control valve; a plurality of selectively deactivatable intake valves each of which is in mechanical communication with a respective one of said plurality of switching hydraulic lifters; and a plurality of selectively deactivatable exhaust valves each of which is in mechanical communication with a respective one of said plurality of switching hydraulic lifters; wherein the number of said at least one solenoid-actuated hydraulic control valves is fewer than the number of said at least half of said plurality of cylinders that are selectively deactivatable; and wherein said electronic control unit is operable to command said at least one solenoid-actuated hydraulic control valve to selectively deactivate said plurality of selectively deactivatable exhaust valves and intake valves only when in or near respective closed positions.