ACCEL 137 Copper Core spark plugs (2401)

Accel HP copper spark plugs are the modernized successors to the Accel U-Groove spark plugs. The HP Copper plugs develop a large spark for more complete combustion. Insulators are made of highly purified alumina powder, superior in strength and thermal conductivity. Glass and copper powder bond the center electrode to the insulator by electroforming process to assure a gas tight seal. An electric heat seal seals tighter for a stable heat range. Plugs feature machine rolled threads for trouble-free installation and removal.