| 摘要 |
An internal combustion engine comprises a cylinder block, an upper crankcase, and a lower crankcase, which comprises an inner casing including an outer wall and the lower main bearing housings, and an outer casing, with a space therebetween. The outer casing has a sump mounted on it. Oil drainage passages from the cylinder head face of the cylinder block extend down to meet a pair of longitudinal passages from which oil drainage ports open into the space between the inner and outer casings. These passages add significantly to the stiffness of the engine. |
