| 摘要 |
<p>PURPOSE:To satisfactorily operate an exhaust timing valve by matte-finishing at least one of the slide surfaces of an exhaust timing valve and a valve guide. CONSTITUTION:An exhaust timing valve 17 and a valve guide 18 are provided in the vicinity of an exhaust port 15 in an engine. A matte-finished surface 33 is formed by shot-peening, sand-blasting or the like in a slide contact surface 31 of the exhaust timing valve 17 which makes contact with a slide surface of a valve guide 18. Even though tar enters between both slide surfaces, the viscosity of the tar is reduced since an oil film is broken. Thereby it is possible to satisfactorily operate the exhaust timing valve.</p> |
