Manley 11389-8 Sodium Dia-Chrome Exhaust Valve 1.625" +.300

Engineered for high-performance and racing applications, these valves are designed to withstand extreme heat and combustion pressures that exceed the capabilities of standard OEM valves.

Key Features:

• Head Diameter: 1.625 inches for optimized flow and sealing surface
• Extended Stem Length: +0.300 inches over standard to accommodate custom head configurations or deck height changes
• Sodium-Filled Construction: Hollow sodium-filled stems dramatically improve heat transfer from the valve head to the guide, reducing operating temperatures and extending valve life
• Dia-Chrome Steel: High-chromium stainless steel alloy provides superior corrosion and heat resistance in harsh exhaust environments
• Racing-Grade Quality: Manufactured to Manley's exacting tolerances for consistent performance across all cylinders

Manley Performance has been a trusted name in professional engine building for decades. The S/D Series valve line is ideal for builds where exhaust temperatures are elevated, such as turbocharged, supercharged, or high-compression naturally aspirated engines. The extended stem length (+.300) makes these valves suitable for applications with non-standard spring retainer heights or custom cylinder head work.