METHOD FOR ASSEMBLING A SPARK PLUG

摘要

A method for assembling a spark plug 20, 66 which includes providing a ground electrode 24 on a spark plug shell 22 having a predetermined final configuration and position and then mounting an insulator 34 in the shell. The distance from a step 38 in an insulator bore 37 to the ground electrode is measured. Based upon this measurement and a desired dimension for a spark gap 56, the dimension on a center electrode 48, 68, 74 between a shoulder 50, 76 and a tip 52, 80 is adjusted so that when the center electrode it disposed in the insulator bore with the shoulder seated on the bore step, the tip forms the desired spark gap with the ground electrode. The center electrode then is assembled into the insulator.