21-4N Stainless Steel Swirl-Polished Valves

The GSC Power-Division intake valve set is engineered to be the best performance and longest-lasting valves available for the aftermarket, specifically designed for the 4G63T engine. Utilizing advanced 3D design and simulation software, these valves feature a stronger, higher-flowing head design that has been flow-tested in specific applications to ensure optimal performance. The 21-4N stainless steel material and chrome polished finish contribute to less valve distortion at the face compared to other designs, ensuring better sealing under extreme conditions and consistent performance throughout their lifespan. Key features of these intake valves include swirl-polished heads for smoother air flow and back-cut valve heads to reduce weight. This weight reduction allows for higher RPM operation, increased boost pressure capabilities, and compatibility with more aggressive cam profiles without necessitating higher valve spring pressures. The micro-polished valve stems minimize oil retention and drag, promoting smoother motion within the valve guides. These intake valves are constructed from modified 21-4N stainless steel, providing high heat capacity and longevity. The valve tips are hardened or feature a stelite wafer tip, ensuring the tip's hardness is within 5 Rockwell C of the rocker or valve tappet for extended life and reduced wear. GSC Power-Division has also adjusted valve tip heights to minimize the need for valve tipping, helping to maintain proper valvetrain geometry and reduce installation time when setting valve lash. Additionally, the keeper groove has been adjusted to balance intake and exhaust spring pressures, reducing the need for valve spring shims and maximizing performance when used with GSC's spring and retainer kits. These valves are compatible with OEM keepers/locks, though replacing old valve locks is recommended for performance applications.