SplitFire SF522D Copper Core Resistor Spark Plug , Pack of 1

The SplitFire Resistor Spark Plugs feature a patented ¿V' design on the side electrode. This is instrumental in helping to improve combustion efficiency. Since the flame kernel is not blocked by the side electrode like other spark plugs, it can travel upward through the ¿V' notch into the combustion chamber. They expose the gas / air mixture to a larger flame kernel for a more aggressive burn. The spark plug has a center electrode with a gasket seat and copper core that aids in cooling. The hex measures 5/8 and they have a precision-tooled metal shell to resist seizing in the cylinder head. Their smooth ceramic insulator eliminates spark flashover that can lead to ignition misfiring and potential damage to your engine. It ensures a tight seal at the plug boot.