Triple ground electrode spark plugs with hybrid type ground configuration.
This bulletin will explain the difference in the air gap setting and main gap setting on hybrid type ground electrode spark plugs, the reason for them, and how to safely check these settings when necessary.
Spark plugs with multiple ground termination points are a great addition to a high-performance application where fouling at low engine speed may be a problem. Understanding the gap setting on this type of spark plug can be confusing due to the multiple gap specifications on hybrid type ground electrode spark plugs. The spark plug gap setting of 0.044+0.022 found in the specification guide is an example of a correct gap setting for this spark plug. The 0.044 specification is referring to the actual gap of the main firing ground electrode, while the 0.022 is referencing the air gap of the side electrodes to the center insulator.
The illustration below shows the location of these air gaps providing better understanding of the two different specifications. These two side ground electrodes are designed to aid in removing carbon deposits that can lead to spark plug fouling. If the center ground electrode becomes fouled the intermittent spark will jump the air gap to the side ground electrode rather than following a path up the ceramic insulator to the shell. Continuing a normal spark event will aid in burning off the unwanted carbon buildup.
Hybrid type ground electrode spark plugs all have a manufacturer set center ground electrode air gap and side ground electrode air gap setting. No attempt should be made to alter these air gaps for any reason. For your curiosity and if the specifications are in question, a wire style gap tool will be needed to safely measure these air gaps. The wire style gap tool will allow you to check the actual air gap without applying pressure to the center electrode or DFE ground electrode in this configuration. Any pressure could damage the electrodes of the spark plug resulting in poor engine performance and in some cases severe internal engine damage.
For addition support contact the GoTech technical services team at 855-207-5630 M-F 7:30-6:00 CST for assistance.