| 摘要 |
PROBLEM TO BE SOLVED: To attain the improvement of an output by collecting an exhaust pipe two by two of each cylinder in a multicylinder 4-cylcle engine of a water glider boat, constituting a single exhaust pipe finally having two exhaust paths separated by a partition, and arranging a variable valve in an opening provided so as to mutually communicate with the partition. SOLUTION: Four exhaust pipes 15 connected to each exhaust port of a 4-cycle straight 4-cylinder engine are linearly extended parallelly to the engine, a length of all the exhaust pipes 15 is almost equalized, each right/left two end parts of each exhaust pipe 15 are collected, an upper/lower two exhaust pipe 15' is formed. This pipe is separated by a partition 18d in the upper/lower center, to be formed as a single cylindrical exhaust pipe 18 having upper/lower two semicylindrical exhaust paths 18c. The upper/lower exhaust paths 18c formed to a base end of the partition 18d of this exhaust pipe 18 are mutually connected by an opening 18e, a variable valve 19 is turnably supported at the opening 18e, to be opened in a high rotational region of the engine, so as to generate an exhaust inertia effect, improvement of an output is attained. |
