What material are these valves made from?

These Manley Race Series exhaust valves are constructed from XH-426 stainless steel. This material is chosen for its durability and ability to withstand high temperatures and demanding engine conditions.

What is the benefit of the swirl polished under head area?

The swirl polished under-head area helps to smooth the airflow as it enters the cylinder. This can contribute to improved airflow dynamics and potentially more efficient combustion.

Are these valves suitable for street use?

Manley Race Series valves are engineered for racing applications like bracket, drag, and oval track racing, operating under 8000 RPM. While durable, they are designed for the specific demands of performance engines.

Manley Chevrolet Big Block Exhaust Valve Kit 11777-8

Name: Manley Chevrolet Big Block Exhaust Valve Kit - 1.940in Head Dia. 5.522in O/A Length, 0.3415in Stem
Brand: Manley Performance
SKU: manley-performance-manley-chevrolet-big-block-exhaust-valve-kit-1-940in-head-dia-t14-879405
Price: 218.97 USD
Availability: BackOrder

Manley Chevrolet Big Block Exhaust Valve Kit - 1.940in Head Dia. 5.522in O/A Length, 0.3415in Stem

$218.97

On Backorder

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

Manley Chevrolet Big Block Exhaust Valve Kit - 1.940in Head Dia. 5.522in O/A Length, 0.3415in Stem. Stainless steel construction for durability.

Key Features

Fits Chevrolet Big Block engines.
Constructed from XH-426 stainless steel for durability.
Features chrome stems and hard tips for enhanced wear resistance.
Swirl polished under head areas and fully machined combustion faces optimize airflow.
Recommended for exhaust valves in alcohol engines.
Suitable for engines operating under 8000 RPM.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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Product Details

These Manley Race Series exhaust valves are made from XH-426 stainless steel, a material chosen for its strength and ability to handle high temperatures. They measure 1.940 inches across the head and are 5.522 inches from end to end, with a 0.3415-inch stem diameter, making them a solid choice for Chevrolet big block engines. The chrome-plated stems and hard tips are there to help them last longer and resist wear, especially in demanding applications like drag or oval track racing where engines might see up to 8000 RPM.

You'll notice the under-head area is swirl polished, which helps smooth out airflow into the cylinder, and the combustion face is fully machined. This attention to detail is meant to help improve airflow and make combustion more efficient. Manley also recommends these for use in alcohol-fueled engines, where they've shown reliable performance under those specific conditions. You can choose between a straight stem or a Race Flo shape depending on what your engine build needs.