| 摘要 |
PURPOSE:To suppress each constitutional part from interfering with each other, by arranging a cooling fan in one side of an engine main unit while providing a push rod insertion hole, intake and exhaust ports and a cooling air path or the like to be arranged with a specific relation to the cooling fan. CONSTITUTION:A cooling fan is arranged in one side of an overheadvalve engine. And the engine forms a push rod insertion hole 11 to one lateral side part of a cylinder head 5 as viewed from a cooling fan side further opens an intake port 14, inducted from a suction port 8, to the other lateral side surface. While an exhaust port 16, inducted from a discharge port 7, is opened to a side surface in the side of providing the cooling fan to be arranged in the cylinder head 5. Further the engine forms the periphery of a rocker arm chamber, provided to be arranged in the top part of the cylinder head 5, in a cooling air passage 19 while a cooling air path 13 in the intermediate between the push rod insertion hole 11 and the exhaust port 16. And one side part of the peripheral wall surface of the exhaust port 16 is formed by one side wall of the rocker arm chamber 18, appearing in the cooling air path 19. |
