Abstract: In a method for making a spark plug (10 and 86) with a predetermined spark gap (37), a method for mounting a center electrode assembly (34 and 85) in an insulator bore (25 and 65). A center electrode blank (48 and 80) is positioned in the insulator bore with a tip (36 and 81) projecting to a predetermined location relative to an external shoulder (22 and 62) on the insulator (11 and 55). A thin walled section (49 and 83) of the center electrode blank located above a step (28 and 67) in the insulator bore is heated and deformed to form a shoulder (39 and 84) contacting the bore step.

Abstract: An improved spark plug for use in an internal combustion engine having a capacitive discharge ignition system. The spark plug includes a conventional metal shell supporting an insulator having a center electrode bore extending therethrough. A center electrode mounted in the insulator bore includes an electrode tip which defines a spark gap with a ground electrode. An auxiliary spark gap is formed within the insulator bore immediately above the tip. A low resistance inductive suppressor is mounted above the auxiliary spark gap and has an end attached to a terminal for connection to the capacitive discharge ignition system.