| 摘要 |
<P>PROBLEM TO BE SOLVED: To discharge exhaust smoothly without complicating a structure, in a port structure of an internal combustion engine. <P>SOLUTION: An upstream part of an exhaust port 41 is substantially formed with a square cross section having two planes parallel to each other, while a throat portion 41a continuing from a combustion chamber 12 is formed with a circular cross section. As a result, the upstream part of the exhaust port 41 and the throat portion 41a are continuously formed with a smooth plane, which prevents separation of exhaust stream to increase an intake flow. <P>COPYRIGHT: (C)2012,JPO&INPIT |
