What are the specific materials used for the intake and exhaust valves?

The intake valves are made from NK-844 material, chosen for its high tensile strength at elevated temperatures. The exhaust valves are crafted from XH-428 material, which offers exceptional strength at high temperatures, nearly double that of common competitor materials.

How durable are these valves under stress?

Manley's Severe Duty? valves have undergone extensive fatigue testing. The exhaust valves, for example, endured up to 100 million cycles at 40,000 psi and 1400°F, demonstrating a significantly longer fatigue life compared to many other valve options.

What is included in this set of valves?

This product includes a set of eight (8) Manley Severe Duty? valves, with specific materials and designs for intake and exhaust applications in Ford 351 Cleveland engines.

Specifications

Brand: Manley Performance
Part #: 11800-8
UPC: 807298052779

Manley Ford 351C 2.190 Inch Head Diameter / .341 Inch Stem / 5.244 Inch Length ( Set of 8)

Name: Manley Ford 351C 2.190 Inch Head Diameter / .341 Inch Stem / 5.244 Inch Length ( Set of 8)
Brand: Manley Performance
SKU: manley-performance-manley-ford-351c-2-190-inch-head-diameter-341-inch-stem-5-244-t14-363758
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 Ford 351C valves. Set of 8, 2.190" head, 5.244" length. XH-428 exhaust, NK-844 intake.

Key Features

Set of 8 Manley Severe Duty? valves for Ford 351 Cleveland engines.
Intake valves are made from NK-844 material, and exhaust valves use XH-428 material for high-temperature strength.
Valves feature chrome stems and hard tips for increased durability.
Swirl-polished under-head areas and machined combustion faces improve airflow and combustion efficiency.
Exhaust valves have undergone rigorous fatigue testing, enduring up to 100 million cycles at 40,000 psi and 1400°F.
Designed for high-temperature gasoline engines.

Secure CheckoutFast Shipping631-982-0042

About this part

Product Details

If you're rebuilding the top end of a Ford 351 Cleveland engine, these Manley Severe Duty? valves are a solid option. This set includes eight valves, with specific materials chosen for intake and exhaust duties to handle high temperatures and stress. The intake valves use NK-844 material, and the exhaust valves are made from XH-428, both selected for their strength at high operating temperatures.

These valves are built for demanding gasoline engines. The exhaust valves have been tested to withstand significant stress and high temperatures for millions of cycles, far outlasting many competitors in fatigue tests. They feature chrome stems and hard tips for improved durability, and the under-head areas are swirl-polished to help with airflow into the combustion chamber. The machined combustion faces also contribute to better airflow and combustion efficiency.

This set is designed for a direct fit in Ford 351 Cleveland engines. You'll want to refer to the manufacturer's installation instructions for specific details on fitting these valves during your engine build.