Anti-carbon fouling spark plug

摘要

A spark plug (100) includes a ground electrode (125), a firing electrode (115), an insulator core (105) having an insulator core nose (120), and an outer shell (110) surrounding the insulator core (105). The improvement includes the insulator core nose (120) including a high temperature glaze applied to an outer surface of the insulator core nose (120) and the high temperature glaze composition. The composition includes, by weight: (i) between about 72 and 84% SiO2; (ii) between about 10 and 20% Al2O3; (iii) between about 2.0 and 2.5% K2O; (iv) between about 0.50 and 0.65% Na2O; (v) between about 3.0 and 5.5% CaO; (vi) between about 0.1 and 0.25% MgO; and (vii) the remainder impurities.