| 摘要 |
PURPOSE:To reduce radiating quantity from an exhaust port and improve heat efficiency, and to prevent crack of the exhaust port and improve durability by forming the exhaust port with heat-insulating and heat-resisting material and making upper and lower cylinder heads pinch it elastically. CONSTITUTION:An exhaust port 7 is formed with heat-insulating and heat- resisting material such as ceramics. And valve side upper and lower end portions and an exhaust manifold 19 side end portion are elastically supported between upper and lower cylinder heads 3, 4 air-tightly through gaskets 9, 10 and a seal ring 22. Then, radiating quantity of exhaust gas from the exhaust port can be reduced and break of the exhaust port formed by fragile ceramics can be prevented. |
