THREE-VALVE TYPE INTERNAL-COMBUSTION ENGINE

PURPOSE:To improve the combustion capacity by shaping a ceiling face of a combustion chamber into two ceiling slopes by a ridge line approximately at the central part for providing the first and the second suction valves on one side and an exhaust valve, an ignition source and a squash part on the other side. CONSTITUTION:A ceiling face 7 of a combustion chamber 6 is composed of two ceiling slopes 71 and 72 going down to both sides from a ridge line 8 approximately in the centeral part; the first and the second suction valve ports 91 and 92 are opened in parallel on the slant face 71, and a single exhaust valve port 10 is opened on the other slant face 72 to be deviated to the opposite side of the 91. A squash part 11 is provided in an area surrounded by a circumferential brim of the combustion chamber 6 and valve ports 92 and 10, and on its side face 11a, torch nozzles 12 and 12 are opened to be approximately directed to the valve port 91. Consequently, an ignition source and the squash part can be arranged in a position where a deisred capacity can be obtained, and the sqash part can give a swirl directed toward the exhaust valve port. This construction permits to intensify the flow of air-fuel mixture and obtain a high compression ratio for improving the combustion as a whole.