MANLEY 11677-8 Exhaust Valve Kit Severe Duty Series for CHEVROLET Gen III/IV Small Block LS1 / LS2 / LS8

Description MANLEY 11677-8 Exhaust Valve Kit Severe Duty Series for CHEVROLET Gen III/IV Small Block LS1 / LS2 / LS8

Manley Severe Duty Valves are designed for high-performance and racing applications. Exhaust valves are manufactured from XH-428 material, while Intake valves are manufactured from NK-844 material.

Severe Duty Valves have undergone rigorous fatigue testing. During normal operation, valves experience 20,000 to 25,000 lbs of applied stress. When valves bounce on the seat, stress increases to 40,000 to 60,000 lbs.

• Designed for high-temperature gasoline engines
• Chrome stems and hard tips for durability and longevity
• Swirl-polished under-head areas and fully machined combustion faces for improved Airflow and combustion efficiency
• XH-428 Exhaust valve material and NK-844 Intake valve material
• Manley Exhaust valve fatigue test: 40,000 psi at 1400°F
• Manley Exhaust valve fatigue life: Up to 100,000,000 cycles
• Competitor fatigue life: 100,000 cycles
• XH-428 ultimate tensile strength at 1500°F: Nearly double that of EV-8
• NK-844 ultimate tensile strength at 1000°F: Over four times that of the competition’s best Intake valve material

Specifications:

• Product Market: Domestic
• Head Diameter: 1.600 IN
• Stem Diameter: 0.3136 IN
• Valve Stem Diameter: 0.3136 IN
• O/A Length: 4.923 IN
• Installed Height: Stock
• Tip Length: 0.175 IN
• Margin Width: 0.065 IN
• Seat Width: 0.115 IN
• Top of Head: 18 Degree Dish
• Underhead Radius: 7/16 IN
• Weight: 92 GR
• Emissions Code: 3
• Cylinder Head: LS6 Cylinder Head
• Valve Series: Severe Duty Series
• Valve Material: Stainless Steel
• Valve Type: Exhaust
• Product Type: Engine Exhaust Valve Kit
• Valve Quantity: 8