5/16 Valve Locks - 10 Degree Radius Groove

PAC Racing Springs 5/16 Valve Locks with 10 Degree Radius Groove are precision-engineered components designed for high-performance engine builds where valve control and reliability are non-negotiable. These titanium valve locks secure the valve spring retainer to the valve stem with a spring-lock design that prevents valve float across the full RPM range, a critical requirement in racing and performance applications where valve train stability directly impacts horsepower delivery and engine longevity.

The 10-degree radius groove geometry is engineered to match valve stem taper and provide consistent engagement across the full valve lift spectrum. Standard height construction ensures compatibility with stock or performance valve springs without requiring spacers or modifications to the valve train geometry. The titanium construction reduces inertial mass compared to steel alternatives, allowing the valve train to respond more quickly to cam profile changes and improving overall engine responsiveness. Each set contains 16 locks—a complete set for an eight-cylinder engine or two sets for V16 configurations. Natural finish titanium resists galling and seizing during assembly and disassembly, extending component service life across multiple engine rebuilds.

These valve locks serve professional engine builders, racing teams, and performance enthusiasts building naturally aspirated and forced-induction powerplants. They are essential for applications where high valve spring pressures demand maximum security—from bracket racing and circle-track competition to street performance builds designed for sustained high-RPM operation. PAC Racing Springs' manufacturing standards ensure consistent tolerances and fit across all 16 pieces in the set, eliminating the risk of premature wear or valve train noise that can result from undersized or inconsistent locks.