What material are these exhaust valves made from?

These Manley Severe Duty exhaust valves are made from XH-428 material. This material is chosen for its high tensile strength at elevated temperatures, making it suitable for demanding engine applications.

What does 'Severe Duty' mean for these valves?

The 'Severe Duty' designation indicates these valves have undergone rigorous testing for fatigue life under high stress and temperature conditions. They are designed to withstand significantly more cycles than standard valves, especially in high-performance or high-heat applications.

Are these valves a direct replacement for all Small Block Chevy engines?

These valves have a 1.600-inch head diameter and a 0.3136-inch stem diameter, and are 0.100 inches larger than stock. While designed for Small Block Chevy engines, it's important to confirm these dimensions and specifications are compatible with your specific cylinder heads and engine build.

Specifications

Brand: Manley Performance
Part #: 12337-8

Manley Small Block Chevy 1.600in Head Dia Severe Duty Exhaust Valves (Set of 8)

Name: Manley Small Block Chevy 1.600in Head Dia Severe Duty Exhaust Valves (Set of 8)
Brand: Manley Performance
SKU: manley-performance-manley-small-block-chevy-1-600in-head-dia-severe-duty-exhaust-t14-808792
Price: 349.40 USD
Availability: BackOrder

$349.40

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

Manley Performance Severe Duty exhaust valves for Small Block Chevy engines. Made from XH-428 material for extreme durability.

Key Features

Fits Small Block Chevy engines.
Set includes 8 exhaust valves.
Each valve has a 1.600-inch head diameter and a 0.3136-inch stem diameter.
Made from XH-428 material, designed for high-temperature gasoline engines.
Features chrome stems and hard tips for enhanced durability.
Swirl polished under head areas and fully machined combustion faces help improve airflow.

These valves are designed for Small Block Chevy engines. Please verify compatibility with your specific engine build.

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About this part

Product Details

Manley Performance is well-known for making strong engine components, and these Severe Duty? exhaust valves are a prime example. If you're building a high-performance Small Block Chevy engine that needs to handle serious heat and stress, these valves are built to last. They are specifically designed for gasoline engines that run at high temperatures, ensuring reliable performance when you push your engine hard.

These exhaust valves are crafted from XH-428 material, which Manley states has nearly double the tensile strength at 1500°F compared to other common exhaust valve materials like EV-8. They've also undergone rigorous 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 feature chrome stems and hard tips for added durability, and the under-head areas are swirl polished to help improve airflow into the combustion chamber.

This set includes eight exhaust valves, each with a 1.600-inch head diameter and a 0.3136-inch stem diameter. They are also designed to be 0.100 inches larger in diameter than stock, which can help improve flow. If you're looking for valves that can withstand demanding conditions and offer improved fatigue life, these are a solid option for your build.