| 摘要 |
PURPOSE:To make output of a front cylinder possible to be brought into full play by setting combustion temperature in a rear cylinder to be yet lower, in case of an engine whose front and rear cylinders are set up in a V-type along the longitudinal direction of a car body. CONSTITUTION:An air-cooled series V-type engine 2 is mounted on a car body of a motorcycle. And the engine 2 is made up of having both front and rear cylinders F and R of the same displacement erected on a crankcase 3. These front and rear cylinders F and R are set up so as to become a V-type in the longitudinal direction looking from the side of the car body 1. In this engine 2, combustion temperature in the rear cylinder R should be set to become lower than that in the front cylinder F. To make the combustion temperature lower, for example, such concrete measures that each compression ratio of these cylinders F and R and each on-off timing of both suction and exhaust valves are varied, and so on, are adopted. |
