Champion Center Electrode Designs

Center electrodes come in a variety of shapes and sizes.

Standard spark plugs typically feature a traditional 2.5mm center electrode. Champion center electrode variations include fine wire, necked down, oversized, and taper cut.

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Originally designed to improve starting and reduce fouling on two-stroke engines, a fine wire electrode was found to improve performance in four-stroke engines as well.

A smaller electrode requires less voltage to jump the gap, resulting in fewer misfires, which translates to increased fuel economy and horsepower. A smaller electrode also reduces flame quenching.

Reducing the electrode size on a standard nickel plug would result in a drastically shortened life span, so the smaller electrodes require exotic metals such as platinum or iridium to maintain (and at times surpass) the longevity of a traditional spark plug.

While a traditional electrode is 2.5mm in diameter, Champion's iridium series features a 0.7mm center electrode.

A necked down center electrode serves a similar function to a taper cut, fine wire and v-cut center electrode. All trimmed designs have the same purpose: to reduce quenching and shadowing by reducing the surface area between the electrodes which could hinder the growth of the flame nucleus.

Oversized electrodes are designed to withstand higher thermal and mechanical shock inherent with high compression motors.

A taper cut center electrode serves a similar function to a necked down, fine wire and v-cut center electrode. All trimmed designs have the same purpose: to reduce quenching and shadowing by reducing the surface area between the electrodes which could hinder the growth of the flame nucleus.