Manley 11631-8 Stainless Steel Engine Valve Race Series 37.5mm Head

The Manley 11631-8 is a precision-engineered stainless steel engine valve, manufactured to Manley Performance's exacting Race Series standards. Featuring a 37.5mm head diameter and a swirl-polished underhead, this valve is built for demanding performance applications ranging from street builds to high-horsepower racing engines.

Key Specifications:

• Head Diameter: 37.5 mm
• Stem Diameter: 0.2345"
• Overall Length: 4.585"
• Tip Length: 0.380"
• Underhead Angle/Radius: 25 x 11/32"
• Margin: 0.080"
• Seat Width: 0.100"
• Top of Head: 20° Dish
• Installed Height: Stock
• Weight: 68g (approximately 0.15 lbs)

Race Series Construction & Features:

• Premium Race Series stainless steel alloy for exceptional durability and heat resistance
• Chrome-plated stems for wear resistance and smooth operation
• Swirl-polished underhead for improved airflow and reduced turbulence
• Fully hardened tips to withstand repeated valve train contact
• Completely machined combustion faces for precise sealing
• Closely controlled margin heights for consistent performance
• Exact stem-to-seat concentricity for superior sealing and longevity

Manley Performance has been manufacturing high-performance stainless steel valves for over 40 years, establishing themselves as an industry standard for quality and performance. These valves are engineered to outflow and outperform in even the most severe operating environments, making the Manley 11631-8 a trusted choice for engine builders tackling everything from mild street performance builds to 1,000+ horsepower race applications.