| 摘要 |
PURPOSE:To omit the working step of removing sand and as well to prevent sand or insulating material from being scattered out of an insulating layer, by constituting such an arrangement that an exhaust port liner is prevented from being deformed or cracking due to thermal expansion and retraction even if the insulating layer is completely sealed. CONSTITUTION:The end part 20a of an exhaust port liner 20 on the side of the combustion chamber 10 of an engine is anchored to projections 14a formed on the inner peripheral surface of a cylinder head 14, and an insulating layer charged with an insulating material 18 is provided on the inner peripheral surface of an exhaust port 16. Further, the other end part 20c of the exhaust port liner 20 on the side of the outlet of the exhaust port 16 is also anchored to projections 14a formed in the inside of the cylinder head 14 so that the insulating layer charged with the insulating material 18 is completely sealed. Further more, the exhaust port liner 20 is formed with, in the intermediate part thereof, an annular recess 20d of substantially ''U'' letter like cross-sectioned shape which may absorb the thermal expansion and retraction of the exhaust port liner 20. |
