Engine with a camshaft with cams part

A motor assembly may include a cam shaft which is rotatably supported on an engine structure. The cam shaft may include a first shaft, a second shaft arranged in the first shaft and is rotatable relative thereto, and a part of cams disposed on the first shaft. The partial cams may have a region with rounded, and may define a portion of the bore. A radial distance is defined by the part of the bore between a first and a second circumferential end of the bore portion may be greater than a radial width of the first shaft or equal to this. The partial cams may define a first recess extending in a radial direction by the bore portion and the partial cams. The cam shaft may include a sleeve which is arranged in a radial passage defined by the second shaft and the recess in the partial cams, the partial cams and radially positioned relative to the second shaft.