| 摘要 |
<p>A small four cycle engine (10) is enclosed having a cylinder head assembly (12) which comprises a cylinder head (48) which cooperates with a cylinder block (16), and a rocker box (50) connected to the cylinder head (48) so as to define an air passage (64) therebetween through which air may pass. The cylinder head (48) has cooling fins (70) projecting into the air passage (64) between the head (48) and box (50) and aligned transversely to a line extending between the axes of the intake and exhaust valves (18, 20). The air passage (64) preferably extends between an intake port (66) and an exhaust port (68), and above an exhaust gas recirculation port (77). A pair of push rod tubes (78, 80) are integral with the rocker box (50) and extend between the box (50) and a crankcase (24) externally of the cylinder block (16). The engine (10) of the present invention also includes a cam tower assembly comprising a base member (86) and a pair of parallel shafts (32, 84) extending from the base member (86).</p> |
