Bourne HPP K-Series High Performance Inlet Valve Spring Set Optimize the breathing of your engine with this premium performance inlet valve spring set, developed by Bourne HPP. Designed to support high-performance cylinder head configurations, these springs offer a critical upgrade for builds pushing beyond factory power limits, ensuring precise valve control during the intake stroke. Engineered for versatility, these inlet springs are rated to handle between 350-700 HP in boosted applications and 200-350 HP in naturally aspirated setups. Despite their enhanced capabilities, they are designed for standard fitment, allowing for a straightforward installation using the original platform shims and retainer setups. Key Specifications Fitment: K20 (Inlet Side) Material: EN 10270-2 SiCr (Silicon Chrome) Wire Diameter: 4.10mm Outside Diameter: 29.90mm Inside Diameter (Min): 21.70mm Free Length: 49.61mm Solid Length: 25.83mm Performance Pedigree These springs are manufactured from high-grade Silicon Chrome alloy (SiCr), selected for its superior fatigue resistance and ability to maintain consistent pressure over time. Whether you are building a high-compression N/A track car or a turbocharged street monster, these springs provide the necessary seat pressure to prevent valve float and ensure maximum airflow efficiency at high RPMs. Kit Contents 8x Bourne HPP Inlet Valve Springs Installation Note: Please note that these are sold in a pack of 8, which covers the inlet side of a standard K-Series cylinder head. When installing, it is critical to verify installed heights and check for coil bind to ensure proper clearance. We recommend professional installation and measurement.
