| 摘要 |
PROBLEM TO BE SOLVED: To improve cooling performance of a cylinder and a cylinder head in a multi-cylinder engine and improve output of the engine in cold start.SOLUTION: In a multi-cylinder engine, a cylinder 13 having plural cylinder bores 17 and a cylinder head having plural combustion chambers corresponding to the cylinder bores, intake ports and exhaust ports 20, that communicate with the combustion chambers, are sequentially joined to an engine case. In the cylinder, a cylinder side cooling oil passage 36 is continuously formed in the vicinity of the respective combustion chambers around the plural cylinder bores 17. In the cylinder head, a cylinder head side cooling oil passage 39 are formed to cover the respective peripheries of the plural exhaust ports 20 and communicate with the cylinder side cooling oil passage 36. Cooling oil cooled in an oil cooler flows through the cylinder side cooling oil passage 36 and then flows through the cylinder head side cooling oil passage 39.SELECTED DRAWING: Figure 5 |
