What material are these exhaust valves made from and why is it important?

These valves are made from XH-428 material, which Manley Performance uses for its exceptional strength at high temperatures. This material is chosen to withstand the intense heat and stress found in high-performance gasoline engines, offering improved durability over standard valve materials.

What does the 'Severe Duty?' designation mean for these valves?

The 'Severe Duty?' designation indicates these valves have undergone rigorous testing and are built with materials and features to handle extreme operating conditions. They are designed to endure significantly more stress and cycles than standard valves, especially in high-temperature environments.

Are these valves sold individually or as a set?

This product is sold as a set of 8 exhaust valves, which is the typical quantity needed for a V8 engine. This ensures you have all the necessary valves for your Big Block Chevrolet application.

Specifications

Brand: Manley Performance
Part #: 11563-8
UPC: 807298050294

Manley Big Block Chevrolet 1.880 Head Dia. 5.354 O/A Length Severe Duty Exhaust Valves - Set of 8

Name: Manley Big Block Chevrolet 1.880 Head Dia. 5.354 O/A Length Severe Duty Exhaust Valves - Set of 8
Brand: Manley Performance
SKU: manley-performance-manley-big-block-chevrolet-1-880-head-dia-5-354-o-a-length-se-t14-626703
Price: 349.40 USD
Availability: BackOrder

$349.40

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Manley Big Block Chevrolet Severe Duty exhaust valves. XH-428 material for high-temp performance.

Key Features

Set of 8 severe duty exhaust valves for Big Block Chevrolet engines.
Constructed from XH-428 material, known for high tensile strength at elevated temperatures.
Features chrome stems and hard tips for improved durability and longevity.
Swirl-polished under head areas and fully machined combustion faces help optimize airflow.
Tested to withstand up to 100 million cycles at 40,000 psi and 1400?F.
Designed for high-temperature gasoline engine applications.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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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, built for Big Block Chevrolet engines that see a lot of hard use. They are designed to handle the intense heat and stress that come with high-performance gasoline engines, making them a solid choice when you're rebuilding or upgrading your top end.

These valves are crafted from XH-428 material, which Manley states has nearly double the ultimate tensile strength at 1500?F compared to other common exhaust valve materials like EV-8. The stems are chromed and the tips are hardened for extra durability, and the under-head areas are swirl-polished to help improve airflow into the cylinder. Manley also put these valves through some serious testing, reporting that they endured up to 100 million cycles in fatigue tests at 40,000 psi and 1400?F, which is a notable improvement over competitor parts that failed much sooner.

This set includes 8 exhaust valves, each with a 1.880-inch head diameter and an overall length of 5.354 inches. If you're working on a high-temperature gasoline engine and need valves that can really take a beating, these are a well-built option.