| 摘要 |
PURPOSE:To improve the extent of combustibility, by forming an exhaust port so as to extend sideway to a cylinder after the part near by a combustion chamber is curved outward almost centering on the center line of a spark plug, in case of an overhead camshaft type three valve multicylinder engine. CONSTITUTION:In case of a device which opens two suction ports 7a and 7b branched off in bifurcation to a combustion chamber 6 of each cylinder 1a at the more one side than a line connecting the cylinder center of each cylinder 1a, and also opens one exhaust port 8 in opposite to the first suction port 7a at the other side, a spark plug 9 is inclinatorily set up so as to adjoin the center of the combustion chamber 6 in the state that its setting angle stands erect. And, the exhaust port 8 is formed so as to extend sideway to the exhaust side after the part 8a nearby the combustion chamber is curved outward with a radius of curvature R in almost centering on a center line l of the spark plug 9. With this constitution, improvement in combustibility and compactification in the overall length of a cylinder head are well promoted. |
