Description Triumph® 500 & 650’s 1951-1962 Triumph® 650 / 750 1963-1983We choose to use the copper based C63000 nickel-aluminium bronze as a material to make our bronze valve guides because of its ideal characteristics for the application. The 5% nickel content provides superior resistance to wear, and the approximately 80 percent copper content delivers outstanding heat conductivity. KPMI® guide profiles are designed to have minimal effect on the airstream while maintaining critical cross sectional thickness in high temperature areas, which promotes high performance and endurance.