| 摘要 |
PURPOSE:To reduce the flowing resistance of intake air by opening an intake passage communicating to an intake valve in the neighborhood of the bore center of a cylinder and intake passages communicating to the other intake valves, on the two side surfaces of cylinder heads provided adjacent to each other respectively out of more than three intake valves provided per cylinder. CONSTITUTION:A recessed part 5 is formed facing to a cylinder 2a in a cylinder block 2, and four intake ports 8a to 8d and two exhaust ports 9a and 9b are opened on the recessed part 5. One intake port 8a out of these intake ports 8a to 8d is provided on a bore center X1, and the other intake ports 8b to 8d are mounted along the circumference of the intake port 8a on one side of the axial line of a crank shaft 1a. Further, in this occasion, in the four intake passages 35a to 35d communicating individually to respective intake ports 8a to 8d, intake passages 35b to 35d are opened in alignment on the one side surface of a head main body 3a, while the intake passage 35a communicating to the intake port 8a in the bore center X1 is opened on the other side surface of the intersecting head main body 3a adjacent to the intake passages 35b to 35d. |
