Engine provided with cooling device in motorcycle

摘要

A motorcycle engine having a cooling device is constructed as an OHC type multi-cylinder engine arranged on a vehicle frame with a plurality of cylinders being aligned perpendicularly to the longitudinal direction of the body frame, wherein a radiator provided with a forced cooling fan and a carburetor leading to engine intake ports are disposed forwardly and rearwardly of the engine, respectively, a timing transmission device for driving a valve-actuating cam shaft of the engine is arranged so as to deviate to one side from the center of the cylinder block in the alignment direction of said cylinders, the timing transmission device and the radiator fan being arranged side-by-side in the longitudinal direction of the frame, a plurality of bearing holders are provided separately on the engine cylinder head correspondingly to the cylinders to rotatably support a valve-actuating cam shaft extending in the alignment direction of the cylinders, and a head cover covering the cylinder head provides wind guiding passages of a concave cross section extending in the longitudinal direction of the frame through between the adjacent bearing holders, outlets of the wind guiding passages being oppossed to the carburetor.