What material are these exhaust valves made from?

These Manley exhaust valves are made from XH-428 material. This material is chosen for its high tensile strength, especially at elevated temperatures like 1500°F.

How do these valves perform under stress and heat?

Manley states these valves have undergone rigorous fatigue testing, enduring up to 100 million cycles at 40,000 psi and 1400°F. This is designed to provide exceptional longevity in demanding engine conditions.

What is the benefit of the swirl-polished under-head areas?

The swirl-polished areas under the head are designed to help optimize airflow into the combustion chamber. This can contribute to improved combustion efficiency.

Specifications

Brand: Manley Performance
Part #: 11679-8
UPC: 807298062808

Manley Chevy LS-7 Small Block Severe Duty/Pro Flo Exhaust Valves (Set of 8)

Name: Manley Chevy LS-7 Small Block Severe Duty/Pro Flo Exhaust Valves (Set of 8)
Brand: Manley Performance
SKU: manley-performance-manley-chevy-ls-7-small-block-severe-duty-pro-flo-exhaust-val-t14-267959
Price: 349.40 USD
Availability: InStock

$349.40

Only 3 left in stock

Manley Chevy LS-7 Small Block Severe Duty/Pro Flo Exhaust Valves (Set of 8). Built for high-temperature gasoline engines with exceptional fatigue life.

Key Features

Set of 8 exhaust valves for Chevy LS-7 small block engines.
Constructed from XH-428 material, offering high tensile strength at elevated temperatures.
Tested to withstand up to 100 million cycles under significant stress and heat.
Designed for high-temperature gasoline engine applications.
Features chrome stems and hard tips for enhanced durability.
Swirl-polished under-head areas and machined combustion faces improve airflow and combustion efficiency.

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About this part

Product Details

Manley Performance is well-known for making strong engine components, especially for racing applications. These Severe Duty exhaust valves are a prime example, designed specifically for Chevy LS-7 small block engines. If you're rebuilding a high-performance engine that runs hot, these valves are built to handle the stress.

Manley uses XH-428 material for these exhaust valves, which they say has nearly double the tensile strength at 1500°F compared to other common materials like EV-8. They've also put these valves through serious fatigue testing, enduring up to 100 million cycles at 40,000 psi and 1400°F, which is a notable improvement over many competitor valves that failed much sooner. The valves also feature chrome stems and hard tips for added durability, and the under-head areas are swirl-polished to help improve airflow into the cylinder.

This set includes eight exhaust valves, enough for a complete engine. They are designed for gasoline engines that operate at high temperatures, making them a solid choice for demanding builds.