Overhead cam follower plunger and ceramic valve arrangement in cylinder head

摘要

A cylinder head includes valves and cam follower plunger cups. The material of the cylinder head (1) has a greater thermal expansion coefficient (A) than that (B) of the valve (2). The plunger has yet a third thermal expansion coefficient (C) greater than that of the cylinder head. Preferably the plunger body (8) has a thermal expansion coefficient about that of the cylinder head, and includes an insert (9) with thermal expansion coefficient (C'') greater than that of the cylinder head. The expansion behaviour of the insert dominates. The plunger is made of hardened steel and the insert is a plastic with the greatest possible expansion coefficient. It is made of polytetrafluoroethylene or fluorinated rubber.