Iridium Saver GK3-7 Spark Plug for Cummins ISL-G
Spark Plug & Boot Kit for the Cummins ISL-G, 6-Cylinder, 8.91 CNG engine
Denso recently released the only aftermarket spark plug designed specifically for this Cummins engine. As the global leader in compressed natural gas (CNG) spark plug technology, Denso has created these unique spark plugs to include two side ground electrodes to block the very rapid gas flow at the spark plug, which allows the proper spark to be generated.
MurCal has created a Kit to Replace Cummins Part # 4955850
We've combined the Denso GK3-7 Iridium Saver Spark Plug and a specially designed rubber boot to create an aftermarket kit that replaces Cummins part # 4955850. The protective rubber boot slides over the spark plug to shield and insulate the plug from the harsh environment of the engine compartment on transit buses, many of which are manufactured with Cummins ISL-G, 6-Cylinder, 8.91 compressed natural gas engines. The spark plug and boot kit can be ordered here.
Why Three Electrodes Is Better Than One
The diagram below illustrates how Denso's improved design, incorporating 3 electrodes, blocks the rapid natural gas flow in a CNG fueled engine. By blocking the onrush of natural gas, the proper spark is generated.