V or horizontally opposed motorcycle engine with overhead camshafts arran ged perpendicular to crankshaft

摘要

A motorcycle engine of V or horizontally opposed type has all of the overhead camshafts extending perpendicular to the axis of the crankshaft (4). The engine also includes an auxiliary shaft (22) extending above the crankshaft (4) and parallel thereto and connected to the crankshaft to rotate therewith. The auxiliary shaft (22) carries two drive gears (24), which cooperate with two driven gears (26) which are connected to respective drive pulleys (28, fig.3) and are mounted to rotate about respective axes parallel to the axes of the overhead camshafts associated with each cylinder, respectively. The inner ends of the camshafts carry respective driven pulleys (10), the two driven pulleys associated with each cylinder being connected to be rotated by a respective one of the drive pulleys (24) by respective drive chains (30). The inlet duct and exhaust duct associated with each cylinder is located at the front and rear of the cylinder spaced apart in the axial direction of the crankshaft.