Brian Crower BC3131 29 mm Exhaust Valve for 2008-2015 Evo X 4B11T

Vehicle Fitment

• 2008-2015 Mitsubishi Lancer Evolution X (GSR and MR trims, 4B11T Turbocharged 2.0L I4)

Features

• 29 mm exhaust valve - factory standard diameter
• One-piece stainless steel construction with friction-welded Stellite tip
• Swirl-polished undercut stem for weight reduction and airflow improvement
• Dished head enhances valve stability at high RPM
• Designed for high-boost, high-temperature, and performance-tuned environments
• Durable design ensures long-term reliability under demanding conditions
• Optimized for use with stock or upgraded valvetrain assemblies
• Sold as a full set of 8 exhaust valves

Specifications

• Material: Heat-resistant stainless steel with Stellite tip
• Head Diameter: 29 mm (standard OE size)
• Stem Diameter: ~5.46 mm
• Overall Length: ~105.9 mm
• Design Features: Dished head, swirl-polished finish, undercut stem

Included Components

• 8x Brian Crower BC3131 29 mm Exhaust Valves (standard size)

Product Description

The Brian Crower BC3131 exhaust valves are precision-engineered replacements built for the 4B11T turbocharged engine in the Mitsubishi Lancer Evolution X (2008-2015, GSR and MR models). With stock-spec 29 mm sizing, these valves offer seamless compatibility with OEM heads while delivering improved durability and high-RPM performance. Crafted from heat-resistant stainless steel with a friction-welded Stellite tip and a swirl-polished undercut stem, these valves reduce reciprocating mass and improve throttle response under demanding conditions.

Designed to withstand the rigors of tuned applications, including high boost and high engine speeds, the BC3131 valves provide enhanced reliability compared to stock components. Sold as a full set of 8, they are ready for direct replacement with no need for modifications. Professional installation and confirmation of valvetrain compatibility are recommended for best performance.