| 摘要 |
An internal combustion engine has an exhaust pipe (117) fastened to a cylinder head (111) by a flange (119) secured by studs (127). The end face (126) of the exhaust pipe (117) directly contacts the cylinder head over an area which is no greater than the cross-sectional area of the adjacent pipe end portion (118), thereby reducing the heat conducted from the exhaust pipe to the cylinder head. The flange (119) is secured to the exhaust pipe by three lugs (128) thereby reducing the thermal mass and the heat absorbed immediately following a cold start. In a modification (Figs.10 and 11, not shown) the end of the exhaust pipe is recessed into the cylinder head to reduce the length of the exhaust port and a wear ring of hard material is interposed between the pipe and the base of the counterbore. In this modification the end face of the pipe end portion is chamfered to further reduce the area in contact with the cylinder head. <IMAGE> <IMAGE> |
