IC engine for e.g. motorcycles has common camshaft parallel to crankshaft, with cams to open and close intake and discharge valves

摘要

The engine has a camshaft (46L,R) coupled to intake (36L,R) and discharge valves (37L,R). The valves are positioned parallel to each other in points, which are offset to one side relative to a plane (38L,R) passing through the axis lines of cylinder bores (21L,R) and crankshaft (29). Cams (48L,R, 49L,R) for direct opening/ closing of the valves are located on the camshaft, which is positioned parallel to the crankshaft so that it is common to intake and discharge valves.