For 4B11T EVO X – GSC P-D STD (29mm) Polished Exhaust Valve – Set of 8 GSC Power Division

For 4B11T EVO X – GSC P-D STD (29mm) Stainless Exhaust Valve – Set of 8.

Stem Diameter (mm): 5.5
Overall Length (mm): 105.85
Head Diameter (mm): 29.00

When creating our new valve line we set out to create the best performance, longest lasting valves available to the aftermarket. Using advanced 3D design and simulation software, we have created a stronger and higher flowing valve head design. We flow test prototype valve heads in the specific applications to make sure we have the highest flowing valve head available on the market today. With the materials used, we have less valve distortion at the face than any of the tested designs. Less distortion allows for better sealing under extreme conditions and more consistent performance throughout the life of the valve. GSC Power-Division’s new valves are sure to become the industry standard for sport compact performance valves.

Valve Features

• Swirl polished heads for smoother air flow over the valve

• Back cut to reduce valve weight for higher RPM, higher boost pressure, and allow for more aggressive cam profiles without increasing valve spring seat pressures

• Valve stems are micro polished to allow for less oil retention on the stem, which creates less drag on the stem to guide for a smoother motion

• Intake valves are a modified 21-4n stainless and exhausts are a modified 23-8n stainless material for high heat capacity while maintaining longevity

• Valve tips are either hardened or have a stelite wafer tip fused so that the tip is within 5 Rockwell C of the rocker or valve tappet for extended life and less wear

• Valve tip lengths – we have taken extra time to adjust tip heights on the applications to require less tipping of the valve, to maintain proper tip height for proper valve train geometry, and to cut down on install times when setting valve lash

• We have also adjusted the keeper groove to properly balance intake and exhaust spring pressures to reduce the use of valve spring shims and maximize performance from our spring and retainer kits

• Valves will work with an OEM keeper/lock or, when available, our upgraded keeper/lock. It is not mandatory, but it is suggested, that any valve lock not be reused on performance applications due to material grooving