Caterpillar Inc.
Piston having smoothed outer crown surface in deposit-sensitive zone

Abstract:

A piston for an internal combustion engine includes a piston crown having a crown outer surface forming piston lands alternating axially with piston ring grooves together with the piston lands defining a deposit-sensitive zone. The crown outer surface is smoothed to inhibit deposit formation and/or adhesion within at least a portion of the deposit-sensitive zone to a roughness average (Ra) of 0.0002 millimeters or less, and in a refinement to a mirror finish Ra of 0.000125 or less.