Patent ID: 8443716

Claim:
A method of forming a piston having a piston head to provide micro chambers for creating and supplying charge ignition radicals to a combustion zone defined in part by the piston head, the piston having an axial length, an annular top side area surrounding a bowl, the bowl formed by a depression in the top side of the piston head, a top piston ring groove adjacent the piston top side area, comprising the steps: forming at least one axially and circumferentially extending groove in the annular top side area of the piston, said groove extending circumferentially along a given length of the annular top side area and defining a length of the micro chamber to be formed in the piston; covering and sealing the groove completely with a plug formed of piston material or piston compatible material while leaving an open area of the groove beneath the plug, said open area defining a volume of the desired micro chamber; permanently securing the plug and piston together; and providing at least one orifice providing communication between the bowl of the piston and the open area of the groove below the plug.