What makes these valves 'Severe Duty'?

The 'Severe Duty' designation comes from the materials used and the rigorous testing these valves undergo. They are made from XH-428 material, which is stronger at high temperatures than common exhaust valve materials, and have been tested to endure significantly more cycles than competing valves.

What is the benefit of the XH-428 material?

XH-428 material offers nearly double the ultimate tensile strength at 1500°F compared to standard EV-8 exhaust valve material. This allows the valves to better withstand the high heat and stress found in demanding gasoline engines.

Are these valves suitable for a stock 351C engine?

While designed for severe duty and high-temperature applications, these valves can be used in a stock 351C if you are looking for an improved, more durable option. They offer enhanced longevity and performance under stress.

Specifications

Brand: Manley Performance
Part #: 11857-8
UPC: 807298054179

Manley Ford 351C 5.167 O/A Length 1.710 Dia Dish Severe Duty Exhaust Valves (Set of 8)

Name: Manley Ford 351C 5.167 O/A Length 1.710 Dia Dish Severe Duty Exhaust Valves (Set of 8)
Brand: Manley Performance
SKU: manley-performance-manley-ford-351c-5-167-o-a-length-1-710-dia-dish-severe-duty--t14-4315314
Price: 349.40 USD
Availability: BackOrder

$349.40

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Manley Severe Duty exhaust valves for Ford 351C. Made from XH-428 material for high temps and improved durability.

Key Features

Fits Ford 351 Cleveland engines.
Set includes 8 severe duty exhaust valves.
Constructed from XH-428 material, offering superior tensile strength at high temperatures compared to standard materials.
Tested to withstand up to 100 million cycles under high stress and 1400°F, far exceeding competitor fatigue life.
Features chrome stems and hard tips for increased durability and longevity.
Swirl-polished under-head areas and fully machined combustion faces improve airflow and combustion efficiency.

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About this part

Product Details

If you're working on a Ford 351 Cleveland engine, especially one that sees hard use or high temperatures, these Manley Severe Duty exhaust valves are a solid choice. They're built from XH-428 material, which is a step up from common EV-8 steel, offering significantly more strength at high temperatures. This means they can handle the stress and heat of demanding gasoline engines without failing prematurely.

Manley put these valves through some serious testing, pushing them to endure up to 100 million cycles under high stress and heat, which is a lot more than many other valves can handle. They also feature chrome stems and hard tips to resist wear, and the under-head area is swirl-polished for better airflow into the cylinder. The machined combustion faces help optimize how the fuel and air mix and burn.

This set includes eight exhaust valves, enough for a complete V8 engine. If your 351C is built for performance or just needs a reliable replacement for a high-stress application, these valves offer a well-built option designed to last.