Kibblewhite Premium C630 Bronze Exhaust Valve Guide Std

Description

The Kibblewhite Premium C630 Racing and Manganese Racing Bronze Valve Guide is designed for high-performance exhaust applications. Made from C630 nickel bronze, it features 80% copper for excellent heat conductivity and 5% nickel for superior wear resistance. This composition allows for tighter clearances, improving valve-to-seat sealing and oil control. The guide profiles are engineered to minimize airflow obstruction while maintaining critical cross-sectional thickness in high-temperature areas, enhancing both performance and durability. In many cases, simply installing these guides can improve airflow without additional modifications. A built-in flange ensures proper protrusion height for optimal seal-to-retainer clearance, eliminating the need for repeated measurements during installation. In applications where a flange would interfere with factory components, a reduced diameter section marks the correct guide protrusion. Tight concentricity tolerances help maintain precise geometry between the seat and guide, reducing material removal during valve jobs and ensuring consistent chamber volumes. For budget-conscious builders, the C67410 Manganese Bronze option offers good anti-galling and seizure resistance, with a 60% copper content that provides better thermal conductivity than iron guides. While not as hard as C630 bronze, manganese guides can be reamed to size using a carbide reamer. High nickel content increases wear and corrosion resistance, which is particularly important when using modern pump and performance fuels. Additionally, aluminum content improves compatibility with aluminum cylinder heads, and a radius transition at the nose profile helps prevent galling during installation. Each kit includes two valve guides unless otherwise noted.