What makes these valves 'Severe Duty'?

The 'Severe Duty' designation comes from the advanced materials like NK-844 for intake valves and rigorous fatigue testing. These valves are built to withstand higher stresses and temperatures than standard valves, especially in demanding engine conditions.

What is the benefit of swirl polished under-head areas?

Swirl polishing the area under the valve head helps to smooth airflow as the air-fuel mixture enters the combustion chamber. This can lead to improved volumetric efficiency and better overall combustion performance.

Do these valves come with any hardware?

This set includes 8 intake valves. It does not include valve springs, retainers, or locks; these components are typically sold separately and should be matched to your engine's specific requirements.

Specifications

Brand: Manley Performance
Part #: 11827-8
UPC: 807298053424

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

Name: Manley SBC 1.600 Severe Duty Intake Valves (Set of 8)
Brand: Manley Performance
SKU: manley-performance-manley-sbc-1-600-severe-duty-intake-valves-set-of-8-t14-4338206
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 SBC Severe Duty Intake Valves (Set of 8). Made from NK-844 material for high-temp gasoline engines.

Key Features

Set of 8 Manley SBC Severe Duty Intake Valves.
Constructed from NK-844 material, offering superior tensile strength at high temperatures.
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 improve airflow.
Underwent rigorous fatigue testing, demonstrating exceptional cycle endurance.

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About this part

Product Details

These Manley SBC Severe Duty intake valves are made from NK-844 material, a choice that offers over four times the ultimate tensile strength of competing intake valve materials at 1000°F. This makes them a solid option for high-temperature gasoline engines where valve stress can reach extreme levels, especially during valve float events. Manley has put these valves through rigorous fatigue testing, with their exhaust valve counterparts enduring up to 100 million cycles at 40,000 psi and 1400°F, far outlasting competitors that failed much sooner.

Beyond the advanced material, these intake valves feature chrome stems and hard tips to improve durability and longevity. The under-head areas are swirl polished, and the combustion faces are fully machined. This design work helps optimize airflow and combustion efficiency within the cylinder. If you're rebuilding a Small Block Chevy engine and need valves that can handle demanding conditions, these are built to perform.