To avoid enlargement of an engine in which a first and a second cam shafts are respectively rotatably supported by a plurality of first and second bearing portions provided in a cylinder head at positions apart from one another in a direction of arrangement of cylinders, a first and a second rotating wheels which are mutually connected for interlocking movement are secured to the first and second cam shafts at the portions projecting from the one-end side first and second bearing portions located on one side along the direction of arrangement of the cylinders among the plurality of first and second bearing portions, and the first rotating wheel is provided with a cylindrical protrusion projecting toward the one-end side first bearing portion rather than the second rotating wheel, by making it possible to arrange both the rotating wheels adjacently to the cylinder head when one of the rotating wheels mutually connected for interlocking movement is provided with the cylindrical protrusion projecting rather than the other of the rotating wheels.
The one-end side first bearing portion 33A is offset and arranged on a side away from the first rotating wheel 51 with respect to the one-end side second bearing portion 34A.
HARA IKUAKI
TAKAGISHI HIROSHI
SHIMOYAMA KAZUAKI
Kazuaki Niki