Exhaust Valve - Extreme Duty - 1.900 in Head - 0.342 in Valve Stem - 6.450 in Long - Stainless - Big Block Chevy - Set of 8

Valve - Exhaust

Manley Severe Duty® Valves deliver the ultimate in strength, reliability, and high-performance durability. Engineered for extreme gasoline engine temperatures, these valves are crafted from exclusive materials (XH-428 for exhaust and NK-844 for intake), offering unmatched tensile strength compared to competitive alloys. In fatigue testing at 40,000 psi and 1400°F, Manley exhaust valves endured 100 million cycles, while competitors failed after just 100,000, proving a 1,000× longer fatigue life. Each valve features chrome stems, hard tips, and swirl-polished underheads with fully machined combustion faces for superior airflow, efficiency, and wear resistance. Built for those who demand race-winning strength and precision, Manley Severe Duty® Valves set the industry standard for performance and endurance.

Part Type

Engine Exhaust Valve

• Chrome stems and hard tips enhance durability
• Exotic alloys for superior tensile strength, reliability, and longevity
• Proven fatigue strength for extreme performance
• Swirl polishing and machined faces improved airflow/optimized efficiency

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Reference Information

Valve, Exhaust, Extreme Duty, XH-432 Xtreme Alloy, 1.90 in Diameter, 0.3415 in. Stem, 6.45 in Length, Set of 8

Manley Extreme Duty Series performance steel valves are a great choice for supercharged, alcohol-burning, or high-revving engines. These engines generate a lot of heat and require special valves that can handle that kind of punishment. All valves are made from the best stainless steel available, with chrome stems and hardened valve tips. Extreme Duty Series valves are swirl-polished and fully machined and available with either undercut heads or straight stems.