What material are these exhaust valves made from?

These Manley Severe Duty exhaust valves are made from XH-428 material. This alloy is chosen for its exceptional strength at high temperatures, offering nearly double the tensile strength of common materials like EV-8 at 1500°F.

How durable are these valves compared to others?

Manley's Severe Duty valves have undergone rigorous fatigue testing and demonstrated impressive endurance. In tests simulating extreme conditions, they endured up to 100 million cycles, significantly outlasting competitor valves that failed much sooner.

Are any other components included with these valves?

This product listing is for a set of eight Manley Severe Duty exhaust valves only. Other engine components, such as intake valves or valve springs, are sold separately.

Specifications

Brand: Manley Performance
Part #: 11825-8
UPC: 807298053387

Manley Ford 427 (Medium/Hi Riser/Tunnel Port) 1.750 Dia Dish Severe Duty Exhaust Valves (Set of 8)

Name: Manley Ford 427 (Medium/Hi Riser/Tunnel Port) 1.750 Dia Dish Severe Duty Exhaust Valves (Set of 8)
Brand: Manley Performance
SKU: manley-performance-manley-ford-427-medium-hi-riser-tunnel-port-1-750-dia-dish-se-t14-307822
Price: 349.40 USD
Availability: BackOrder

$349.40

On Backorder

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Manley Performance Severe Duty exhaust valves for Ford 427 engines. Built with XH-428 material for extreme durability.

Key Features

This product is a set of 8 Manley Severe Duty exhaust valves.
Designed for Ford 427 engines with Medium/Hi Riser or Tunnel Port cylinder heads.
Constructed from XH-428 material, offering superior high-temperature tensile strength.
Features chrome stems and hard tips for enhanced durability and longevity.
Swirl polished under head areas and fully machined combustion faces improve airflow.
Tested to withstand up to 100 million cycles under extreme stress and temperature conditions.

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About this part

Product Details

This set includes eight Manley Severe Duty exhaust valves, specifically designed for Ford 427 engines with Medium/Hi Riser or Tunnel Port cylinder heads. These valves are constructed from XH-428 material, a high-strength alloy chosen for its exceptional performance in demanding, high-temperature gasoline engine applications.

Manley's Severe Duty valves have undergone extensive fatigue testing, demonstrating remarkable endurance. In rigorous tests simulating extreme operating conditions, these exhaust valves endured up to 100 million cycles at 40,000 psi and 1400°F, far outlasting competitor valves that failed after only 100,000 cycles. This is thanks to the XH-428 material, which offers nearly double the tensile strength at 1500°F compared to other common exhaust valve materials like EV-8. The valves also feature chrome stems and hard tips for added durability, along with swirl-polished under-head areas and fully machined combustion faces to promote better airflow and combustion efficiency.

These valves are a solid option for builders looking for robust components that can handle the stress of high-performance engines. For installation, always refer to the manufacturer's specific instructions to ensure proper fitment and function within your engine build.