TWO-STEP CAM CONTROLLED EXHAUST VALVE DEACTIVATION TO OPERATE A DIVIDED EXHAUST BOOST SYSTEM

An exhaust system includes a plurality of cylinders, and each cylinder includes a scavenge exhaust valve and a blowdown exhaust valve. A scavenge path leads from the scavenge exhaust valves and a blowdown path leads from the blowdown exhaust valves. An arrangement activates and deactivates the scavenge exhaust valves and the blowdown exhaust valves. Further included is a cam shaft including a plurality of scavenge cams and a plurality of blowdown cams. During rotation of the cam shaft, the scavenge cams interact with the scavenge exhaust valves to open and close the scavenge exhaust valves when the scavenge exhaust valves are activated. Additionally, during rotation of the cam shaft, the blowdown cams interact with the blowdown exhaust valves to open and close the blowdown exhaust valves when the blowdown exhaust valves are activated, and at different times with respect to the opening and closing of the scavenge exhaust valves.