Manley 11638-8 Stainless Steel Performance Valves

The Manley 11638-8 is a high-performance stainless steel valve engineered for demanding applications. Featuring a 46.83mm head diameter, .2750" stem diameter, and 4.630" overall length, this valve is precision-manufactured to deliver superior flow and durability in both street and race environments.

Key Specifications:

• Head Diameter: 46.83mm
• Stem Diameter: .2750"
• Overall Length: 4.630"
• Tip Length: .470"
• Underhead Angle/Radius: 10° x 3/8"
• Margin: .050"
• Seat Width: .080"
• Top of Head: 5° Dish
• Weight: 82 grams
• Installed Height: Stock

Performance Features:

• Manufactured from Manley's Race Series stainless steel alloy for exceptional strength and heat resistance
• Chrome-plated stems for superior wear resistance and reduced friction
• Swirl-polished underheads for optimized flow characteristics
• Fully hardened tips for extended durability with aggressive valve train components
• Completely machined combustion faces for precise sealing
• Exact stem-to-seat concentricity for reliable sealing and consistent performance

Manley Performance has been the industry standard in high-performance valves for over 40 years. These valves are engineered to outflow and outperform competitors in the most demanding conditions, from street performance builds to 1000+ horsepower racing applications. Each valve undergoes rigorous quality control to ensure it meets Manley's exacting standards for professional engine builders and racers.