| 摘要 |
PROBLEM TO BE SOLVED: To improve engine performance by making group-exhausting possible from multiple cylinders with a simple structure and a satisfactory manufacturability and design and preventing exhaust interference. SOLUTION: This exhaust system has plural independent exhaust passages 58, 59 extending in a vertical direction integrally formed on a cylinder block 5 of a four-cycle multi-cylinder engine longitudinally mounted so as to direct a crankshaft to the vertical direction, and each of exhaust passage 58, 59 is communicated with exhaust ports 19A-19D of multiple cylinders 10A-10D where exhaust timing is not continuous with each other. The exhaust port 19D of the cylinder 10D placed at a lower position among the multiple cylinders 10A-10D is communicated with the exhaust passage 58 of the far side among the plural exhaust passage 58, 59, and the exhaust passage 58, 59 are joined at a lower position than a communicating position of the exhaust port 19D of the cylinder 10D positioned at the lowest position. |
