GSC Exhaust Valve 33mm / +1mm Standard (Subaru EJ20 / EJ257 Turbo) GSC2013-01

GSC Power-Division +1mm Oversized Exhaust Valve, Single (Subaru EJ20 / EJ257 Turbo) - GSC2013-01

Looking to unlock more power and enhanced airflow from your Subaru EJ series turbo engine? The GSC Power-Division +1mm Oversized Exhaust Valve is the ideal upgrade. This high-performance, single valve is engineered using advanced 3D design and simulation software to create a stronger, higher-flowing valve head. Each prototype is meticulously flow-tested for its specific application, guaranteeing maximum efficiency. The superior materials and design minimize valve face distortion, providing a better seal and more consistent performance throughout the life of your engine.

Key Performance Features

• +1mm Oversized Design: This larger 33mm head diameter is engineered to significantly increase airflow and exhaust gas scavenging, resulting in more power for high-performance builds.
• Swirl Polished Heads: Precision polishing promotes smoother airflow over the valve, optimizing performance.
• Back-Cut Design: Reduces valve weight, a critical factor for high-RPM and high-boost applications, and allows for more aggressive cam profiles without requiring increased valve spring seat pressures.
• Micro-Polished Stems: The valve stems feature a micro-polished finish to reduce oil retention and friction, ensuring a smoother motion within the valve guide for extended longevity.
• Advanced 23-8N Stainless Material: Constructed from a modified stainless alloy specifically chosen for exhaust valves, offering exceptional resistance to extreme heat while maintaining long-term durability.
• Hardened Tips: Tips are hardened or feature a stellite wafer for maximum resistance to wear from the rocker or tappet, extending valvetrain life.

Installation & Fitment

The GSC2013-01 is a single, oversized valve designed to fit Subaru EJ20 and EJ257 turbo engines. Note: Due to the +1mm oversized nature, cylinder head machine work is required for proper installation. GSC has fine-tuned the valve tip lengths to ensure proper valvetrain geometry and reduce installation time by minimizing the need for extensive valve tipping during lash adjustments. This valve is compatible with both OEM and upgraded keepers/locks. While not mandatory, it is highly recommended to use new valve locks for any performance application, as used locks may have material grooving from previous use.