| 摘要 |
Exhaust ports (8 and 9) of paired middle cylinders (#2 and #3) in which respective power strokes take place with one intervening power stroke therebetween are joined together in a cylinder head (1) to form a joint exhaust port (11). Exhaust ports (7 and 10) of paired end cylinders (#1 and #4) in which respective power strokes take place with one intervening power stroke therebetween extend from the respective cylinders (#1 and #4) toward the joint exhaust port (11). Then, on the respective sides of the joint exhaust port (11), the exhaust ports (7 and 10) extend along the joint exhaust port (11) to a side wall face (5) of the cylinder head (1) while the exhaust ports (7 and 10) and the joint exhaust port (11) are separated from each other by respective thin walls (12 and 13). |
