Tempest URHM40E Massive Electrode Spark Plug, 3/4"-20 Thread

Tempest Plug Eligibility Guide

High Conductivity Copper Core Center Electrode
Copper, co-extruded inside a nickel alloy sleeve ensures outstanding heat and electrical conductivity while the nickel sleeve offers high resistance to corrosive combustion gases.

Proprietary Glass Center Seal
21st century “fired in” resistor replaces the multipart screw, spring, and carbon pile stack up used in competitive plugs and known to suffer from resistance value instability that can cause misfires, wasted fuel, and engine roughness.

High Alumina Ceramic Insulator
High mechanical strength, superior dielectric properties, and proprietary protective glaze, provides high performance to conquer severe operational conditions. “Clean Collar” massive electrode “V” tip focuses heat to reduce fouling and enhance heat range control.

Nickel Finish
Environmentally preferable electrolytic nickel provides outstanding durable finish, superior corrosion protection, and extreme wear resistance.

Nickel Ground Electrodes
Aviation grade nickel electrode design focuses on minimizing sparking voltage requirements while maintaining specification gaps to ensure large, stable “flame kernels” for on-time ignition and complete combustion.

Vacuum Infused Center Electrode
The proprietary vacuum infusion process seals the electrode/insulator gap providing stable heat range and superior center electrode cooling (heat flow to the insulator).

Hot-Lock Assembly
Intense pressure and heat create positive, zero-leakage, shrunken in seal between insulator and shell to contain the hot, high pressure combustion cycle gases.

Harness Wire Contact
The spring contact surface is smooth, uninterrupted, oxide-treated, and corrosion resistant. It’s chemically bonded to the fired-in resistor providing the ultimate harness/spark plug termination integrity and energy transfer.