What material are these intake valves made from?

These intake valves are made from Manley's NK-844 material. This material is chosen for its high tensile strength, especially at elevated temperatures found in high-performance gasoline engines.

What makes these valves 'Severe Duty'?

The 'Severe Duty' designation comes from extensive fatigue testing. These valves have demonstrated the ability to withstand millions of cycles under high stress and temperature conditions, far exceeding the lifespan of many standard valves.

Are these valves a direct replacement for all Big Block engines?

These are stock length valves with a 11/32 inch stem diameter, designed for Big Block engines. It's always recommended to verify the specific dimensions and requirements for your engine build to ensure proper fitment.

Specifications

Brand: Manley Performance
Part #: 11817-8
UPC: 807298053189

Manley Dart Big Block Pro 1 Stock Length 11/32in Stem Dia Severe Duty Intake Valves (Set of 8)

Name: Manley Dart Big Block Pro 1 Stock Length 11/32in Stem Dia Severe Duty Intake Valves (Set of 8)
Brand: Manley Performance
SKU: manley-performance-manley-dart-big-block-pro-1-stock-length-11-32in-stem-dia-sev-t14-4331915
Price: 349.40 USD
Availability: BackOrder

$349.40

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Manley Severe Duty Intake Valves (Set of 8). Built with NK-844 material for high-temp gasoline engines.

Key Features

Set of 8 Manley Severe Duty intake valves.
Constructed from NK-844 material, offering high tensile strength at elevated temperatures.
Designed for high-temperature gasoline engines.
Features swirl-polished under head areas and fully machined combustion faces for improved airflow.
11/32 inch stem diameter with chrome stems and hard tips for enhanced durability.
Rigorous fatigue testing shows exceptional cycle life under stress.

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About this part

Product Details

Manley Performance is well-known for making strong engine components, and their Severe Duty? Valves are a prime example. If you're rebuilding the top end of a big block engine, especially one that sees high temperatures, these intake valves are built to last. They use a special NK-844 material that has significantly higher tensile strength at high temperatures compared to other common intake valve materials.

These valves are designed for improved airflow and combustion efficiency, thanks to swirl-polished under-head areas and fully machined faces. The 11/32 inch chrome stems and hard tips add to their durability, making them a solid choice for demanding gasoline engines. Manley has put these valves through rigorous testing, showing they can withstand millions of cycles under high stress, far outlasting many competitor parts.

This set includes eight intake valves, ready to be installed in your big block build. Make sure to check the manufacturer's installation instructions for proper fitment and procedures.