Patent ID: 8857177

Claim:
A piston engine, comprising: at least one cylinder in communication with a fresh-gas line that is at least one of unthrottled and dethrottled, the at least one cylinder having at least a first discharge valve and a second discharge valve; and a double overhead camshaft for controlling the first and a second discharge valves, wherein the double overhead camshaft includes an inner shaft, which has at least one first cam for controlling the first discharge valve, and an outer shaft that is coaxial to said first inner shaft and has at least one second cam for controlling the second discharge valve, wherein all cylinders of the piston engine have the first and second discharge valves that are separately controllable by the shafts of the double overhead camshaft, and wherein the inner shaft and the outer shaft are rotationally adjustable relative to one another to change the discharge timing of the first and second discharge valves.