| 摘要 |
PROBLEM TO BE SOLVED: To provide an internal combustion engine cylinder head capable of preventing an increase in a back pressure of exhaust gas discharged from a combustion chamber to a linear exhaust port, and preventing the degradation of exhaust gas discharge performance.SOLUTION: In a linear exhaust port 13 formed to be smaller in passage length than a curved exhaust port and having an inside diameter gradually larger from a combustion chamber 7B toward an exhaust gas collection portion 14, if a bottom surface of the exhaust gas collection portion 14 is defined as a reference surface 18 and a virtual extension surface 19 of the reference surface 18 extending toward an upstream end side of the linear exhaust port 13 is provided, a swollen portion 20 is formed on a bottom surface of the linear exhaust port 13 to be swollen upward of the virtual extension surface 19.SELECTED DRAWING: Figure 6 |
