A cylinder head and a method for producing a valve seat

摘要

A cylinder head, in particular for a 4-cycle stroke internal combustion engine, comprises an air intake system having an intake passage communicating with a combustion chamber at an intake port and an exhaust system being an exhaust passage communicating with the combustion chamber of an exhaust port. Said ports are provided with valve seats at respective peripheral edges and a minimal inner diameter (A,C) of at least one of said valve seats (4,5) is larger than a minimal diameter (B,D) of an associated intake or exhaust passage upstream or downstream of said valve seats. <IMAGE>