Manley Performance LS-1/LS-2 Small Block Severe Duty Exhaust Valves Set of 8 - Part No. 11675-8

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. Head Diameter: 1.575 in. - Stem Diameter: .3136 in. - O/A : 4.923 Manley Valve - Exhaust, Valve-LS1 S/D 1.575.

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

Upgrade your Chevrolet LS-1 or LS-2 small block engine with the Manley Performance Severe Duty Exhaust Valves, part number 11675-8. Designed for high-performance applications, these valves are crafted from exclusive alloys (XH-428 for exhaust) to deliver exceptional tensile strength, reliability, and longevity. Engineered to withstand extreme engine temperatures, they are ideal for race cars and high-performance street builds. Each valve features chrome stems, hard tips, and swirl-polished underheads, which optimize airflow and improve combustion efficiency. The fully machined combustion faces ensure superior sealing and reduced wear, contributing to increased engine durability and consistent power output. These valves have undergone rigorous fatigue testing, surviving over 100 million cycles at 40,000 psi and 1,400°F, demonstrating their superior endurance compared to standard valves. The set includes eight valves designed specifically for LS-1 and LS-2 engines, making them a direct replacement for stock components while providing a significant upgrade in strength and performance.

Features:

• Swirl-polished underheads and machined faces for optimized airflow and efficiency

• Constructed from exotic alloys (XH-428 for exhaust) for superior tensile strength and durability

• Proven fatigue strength with endurance over 100 million cycles at extreme temperatures

• Chrome stems and hardened tips enhance wear resistance and longevity

Air Freight Prohibited: false
Not Carb Approved: false
Ltl Freight Required: false
Prop 65: Y
Part Type: automotive
Epa: N/A
Carb Acknowledgement Required: false
Regular Stock: false
Units Per Sku: 1
Clearance Item: t