Tenneco Inc.
Piston and method of making a piston

Abstract:

A one-piece piston including a combustion bowl which is cast to its final form and includes at least one irregularity spaced from a central axis. The piston is initially fabricated of an upper crown member and a lower crown member, which are joined together. The piston is then chucked into a machine tool, such as a CNC lathe, which locates either the piston's top surface or a portion of the combustion bowl and establishes its location as a datum plane. It is this datum plane which serves as a reference location for subsequent machining operations of the piston.