What makes these Manley valves 'Severe Duty'?

The 'Severe Duty' designation comes from the advanced materials used, like the NK-844 intake valve material, and the extensive fatigue testing they undergo. These valves are built to withstand significantly higher stress and more cycles than standard valves, making them suitable for high-performance and high-temperature engine applications.

Are these valves a direct replacement for all LS engines?

These valves are specifically listed for Chevy LS-1, LS-2, and LS-6 small block engines. While they share common dimensions, it's always best to verify the specific valve requirements for your particular LS engine variant and cylinder head configuration before installation.

What is the benefit of hollow stem valves?

Hollow stem valves are lighter than solid valves. This reduced weight allows the valvetrain to operate more reliably at higher RPMs, as there's less inertia for the springs and other components to control. This can lead to improved engine response and stability at high engine speeds.

Specifications

Brand: Manley Performance
Part #: 11682H-8
UPC: 807298069715

Manley Chevy LS-1/LS-2 (LS-6) Head Small Block Severe Duty/Pro Flo Hollow Intake Valves (Set of 8)

Name: Manley Chevy LS-1/LS-2 (LS-6) Head Small Block Severe Duty/Pro Flo Hollow Intake Valves (Set of 8)
Brand: Manley Performance
SKU: manley-performance-manley-chevy-ls-1-ls-2-ls-6-head-small-block-severe-duty-pro--t14-106592
Price: 805.63 USD
Availability: BackOrder

$805.63

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Manley Chevy LS-1/LS-2 (LS-6) Severe Duty/Pro Flo Hollow Intake Valves (Set of 8). These well-built valves offer improved fatigue life for high-temp engines.

Key Features

Set of 8 hollow intake valves for Chevy LS-1, LS-2, and LS-6 small block engines.
Intake valves made from NK-844 material, offering significantly improved tensile strength at high temperatures compared to competing materials.
Proven fatigue life, enduring up to 100 million cycles in rigorous testing, far exceeding competitor performance.
Designed for high-temperature gasoline engines, helping maintain performance under demanding conditions.
Features chrome stems and hard tips for enhanced durability and longevity.
Swirl polished under head areas and fully machined combustion faces optimize airflow and combustion efficiency.

These valves are specifically designed for Chevy LS-1, LS-2, and LS-6 small block engines. Always confirm compatibility with your specific engine build.

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About this part

Product Details

Manley Performance is known for making strong engine components for racing and high-performance applications. These Severe Duty/Pro Flo hollow intake valves are a prime example of that dedication, built specifically for Chevy LS-1, LS-2, and LS-6 small block engines. If you're pushing your LS engine hard, especially in high-temperature conditions, these valves are designed to handle the stress and keep your engine running efficiently.

What really sets these valves apart is the material and the testing behind them. The intake valves use NK-844 material, which Manley states has over four times the ultimate tensile strength of competing intake valve materials at 1000°F. They've also undergone rigorous fatigue testing, enduring up to 100 million cycles under high stress, which is a staggering 1000 times longer than some competitors that failed after just 100,000 cycles. This means they're built to last even when subjected to the extreme forces and temperatures found in performance engines. The valves feature chrome stems and hard tips for added durability, and the under-head areas are swirl polished with fully machined combustion faces to help improve airflow into the cylinder and optimize combustion.

This set includes eight hollow intake valves, each measuring 2.080 inches in head diameter, with a .3133-inch stem diameter and an overall length of 4.874 inches. If you're rebuilding or upgrading the top end of your LS engine and need components that can withstand severe duty, these Manley valves are a solid option.