| 摘要 |
PURPOSE:To reduce the overall size of an engine and to activate a catalyst converter and an exhaust reactor, by a method wherein an exhaust valve is positioned facing the one side of a suction valve, an ignition source is situated opposite to the other side thereof, and exhaust valve ports of adjoining combustion chambers are positioned adjacent to each other. CONSTITUTION:Two suction valve ports 8a and 8b with the same diameter are formed parallel to each other on one side 7a of a roof surface 7 of each of combustion chamber 61-64. Further, exhaust valve ports 121-124 are opened in other side 7b of the roof surface 7. Ignition plugs P1 and P4 are disposed outside a cylinder head 2, while ignition plugs P2 and P3 are disposed close to the center of the cylinder head 2. Additionally, exhaust valve ports 121, 122 and 123, 124 of adjoining combustion chambers 61, 62 and 63, 64, respectively, are positioned adjacent to each other. This reduces the overall size and the weight of an engine, and enables promotion of activation of a catalyst converter and an exhaust reactor, which are connected to an exhaust system. |
