| 摘要 |
PROBLEM TO BE SOLVED: To prevent the temperature of lubricating oil in an oil pan from raising abnormally by guiding exhaust gas, which flows into an exhaust passage by an exhaust communication pipe in a wall part of a cooling water passage of a crankcase, in the direction for receding from the bottom of the crankcase. SOLUTION: A water jacket 51 and a cooling water passage 31 of a crankcase 23a are communicated with each other by a cooling water communication passage 52 which is integrally formed in an exhaust communication pipe 48. The cooling water passage 31 of the crankcase 23a is projected downward so as to form a wall part 54 and the wall part 54 is so constituted that the exhaust gas which flows horizontally into an exhaust passage 47 is guided in the direction for receding from the bottom of the crankcase 23a, namely an oil pan, by the exhaust communication pipe 48. This constitution prevents high-temperature exhaust gas from directly touching the bottom wall of the oil pan and consequently prevents the temperature of the lubricating oil in the oil pan from raising abnormally. |
