Bourne HPP Exhaust Valve Springs Honda K20 K24

Bourne HPP K-Series High Performance Exhaust Valve Spring Set

Secure the reliability of your engine's exhaust cycle with this premium performance exhaust valve spring set, developed by Bourne HPP. Designed to withstand the immense heat and pressure of high-output configurations, these springs offer a critical upgrade for builds pushing beyond factory power limits.

Engineered for versatility, these exhaust 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 (Exhaust 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 specifically for its superior fatigue resistance and thermal stability under high exhaust temperatures. 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 maintain seal integrity against high backpressure.

Kit Contents

• 8x Bourne HPP Exhaust Valve Springs

Installation Note: Please note that these are sold in a pack of 8, which covers the exhaust 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.