What makes these valves 'Severe Duty'?

The 'Severe Duty' designation comes from the advanced materials and rigorous testing Manley performs. These valves are made from XH-428 material, which offers significantly higher tensile strength at high temperatures, and they've been tested to endure up to 100 million cycles, far beyond typical valve requirements.

What is the benefit of the XH-428 material for exhaust valves?

XH-428 is a specialized material that Manley uses for its exhaust valves. It provides nearly double the ultimate tensile strength at 1500°F compared to common materials like EV-8, allowing the valves to withstand extreme heat and stress without deforming or failing.

Do these valves come with intake valves as well?

This specific product listing is for a set of 8 Manley SBC Severe Duty EXHAUST valves only. Manley also offers intake valves made from NK-844 material, but they are sold separately.

Specifications

Brand: Manley Performance
Part #: 11543-8
UPC: 807298049953

Manley SBC 1.600 Severe Duty Exhaust Valves (Set of 8)

Name: Manley SBC 1.600 Severe Duty Exhaust Valves (Set of 8)
Brand: Manley Performance
SKU: manley-performance-manley-sbc-1-600-severe-duty-exhaust-valves-set-of-8-t14-173512
Price: 349.40 USD
Availability: BackOrder

$349.40

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Manley SBC 1.600" Severe Duty Exhaust Valves (Set of 8). Built for high-temperature gasoline engines with exceptional fatigue life.

Key Features

Set of 8 Manley Severe Duty exhaust valves for Small Block Chevy engines.
Constructed from XH-428 material, offering exceptional tensile strength at high temperatures.
Tested to withstand up to 100 million cycles under high stress and heat, far exceeding competitor fatigue life.
Designed for high-temperature gasoline engines, handling demanding operating conditions.
Features chrome stems and hard tips for added durability and longevity.
Swirl-polished under-head areas and fully machined combustion faces improve airflow and combustion efficiency.

These valves are designed for Small Block Chevy engines. Always confirm compatibility with your specific engine build and manufacturer specifications.

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About this part

Product Details

Manley Performance is well-known for making strong internal engine components, especially for racing applications. These Severe Duty exhaust valves are a prime example of that commitment, designed to handle the intense conditions found in high-temperature gasoline engines. If you're rebuilding a Small Block Chevy and want parts that can take a beating, these are worth a close look.

What really sets these valves apart is the XH-428 material used for the exhaust side. Manley states this material has nearly double the tensile strength at 1500°F compared to other common exhaust valve materials. They've also put these valves through some serious testing, showing they can endure up to 100 million cycles under high stress and heat, which is a remarkable improvement over typical competitor parts. The chrome stems and hard tips add to their durability, and the swirl-polished under-head areas and machined faces help improve airflow into the combustion chamber.

This set includes eight exhaust valves, enough for a standard V8 engine. While these are built for demanding use, they are designed to fit standard Small Block Chevy applications. Make sure to check your specific engine's requirements to confirm compatibility.