| 摘要 |
PURPOSE:To form an insulating space with even gap along nearly whole length of the exhaust port, by using specified core. CONSTITUTION:A pair of upper and lower split parts 2, 3 press-formed of metal plate having heat resisting and corrosion resistance property taking prescribed space for plural projection 4, after pipe shape exhaust port liner 1 has been formed joining them, core 7 for casting is provided with sand 5 for casing on the outer recess and sand core 6 inside the port, which is charged to form. When the cylinder head 8 is casted to form, the core 7 is casted in a body to the corresponded spot to the exhaust port, sand 5 for casting and sand core 6 are removed from the cylinder head 8 after casting. Thereby the top of every projection 4 of exhaust port liner 1 is joined to the inner wall of the exhaust port of the cylinder head 8, even insulating space 9 is formed nearly whole around of the exhaust port between outer surface of exhaust port liner 1 and the inner wall of the exhaust port. |
