8.5mm Bulk Spark Plug Wire - 100'

The MSD IGNITION 8.5mm Bulk Spark Plug Wire – 100 Feet is a professional-grade ignition conductor engineered for high-performance engine applications requiring reliable spark delivery over extended distances. This spiral-core, silicone-jacketed wire is designed to handle demanding conditions where maintaining consistent ignition timing and signal integrity across a full 100-foot bulk spool is critical to engine performance and tuning flexibility.

The 8.5mm conductor diameter strikes a balance between current-carrying capacity and flexibility, allowing for clean routing through tight engine compartments without signal degradation. Silicone insulation provides superior temperature resistance and ozone resistance compared to older PVC jackets, extending service life in high-heat engine bays and ensuring the wire remains pliable even after years of thermal cycling. The spiral core design minimizes electromagnetic noise that can interfere with sensitive engine management systems, resulting in cleaner spark events and more predictable combustion timing. Red color facilitates quick identification and organized wire management during installation or troubleshooting.

This bulk format serves engine builders, restoration shops, and performance tuners who need the flexibility to cut custom lengths for specific engine configurations—whether fabricating harnesses for street-engine builds, classic car restorations, or competition vehicles. The 100-foot quantity reduces per-foot cost for multi-vehicle projects or shop inventory, making it economical for professionals managing multiple ignition installations without excess scrap waste.

MSD Ignition is established as a premier manufacturer of ignition components for high-performance and race-oriented powerplants, and their spark plug wire formulations are widely recognized in the automotive performance community for consistent conductivity and durability under sustained high-RPM operation and elevated under-hood temperatures.