The ignition system used on these engines is a High-Energy Ignition (HEI) system with Electronic Spark Timing (EST). The High-Energy Ignition (HEI) system controls fuel combustion by providing a spark to ignite the air/fuel mixture at the appropriate time.
The ignition circuit consists of the battery, the distributor, the ignition switch, the spark plugs, and the primary and secondary wiring.
The spark plug wires used with the HEI system are composed of four major components:
An 8 mm silicone jacket for high temperature protection. This outer jacket also provides excellent insulation for the high voltage produced in the HEI system.
A reinforced fiberglass braid for strength.
Inner core insulation is composed of Ethylene Propylene Diene Monomer (EPDM) for strength and voltage insulation.
A composite High Temperature (CHT) core composed of aramid fibers impregnated with conductive latex and wrapped with conductive silicone.