What does the '+.100' sizing mean for these valves?

The '+.100' indicates that these valves are 0.100 inches larger in diameter than a standard valve. This means the cylinder head's valve seats and guides must be machined to accept this larger size for proper fitment and sealing.

What kind of applications are these valves best suited for?

These valves are specifically designed for extreme applications that generate high heat and force. This includes Top Fuel and Funny Car drag racing, as well as high-performance marine engines where durability and heat resistance are critical.

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

The swirl polishing process creates a smoother surface on the underside of the valve head. This helps to reduce turbulence and improve the flow of the air-fuel mixture into the cylinder, contributing to better engine performance.

Specifications

Brand: Manley Performance
Part #: 11701-8
UPC: 807298056333

Manley Extreme Duty Stainless Steel Exhaust Valves 1.600, +.100 - Set of 8

Name: Manley Extreme Duty Stainless Steel Exhaust Valves 1.600, +.100 - Set of 8
Brand: Manley Performance
SKU: manley-performance-manley-extreme-duty-stainless-steel-exhaust-valves-1-600-100--t14-4338202
Price: 596.61 USD
Availability: BackOrder

$596.61

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Manley Extreme Duty Stainless Steel Exhaust Valves. Set of 8, 1.600" diameter, +.100" over size. Built for extreme heat and force.

Key Features

Set of 8 Manley Extreme Duty Stainless Steel Exhaust Valves.
Valve diameter is 1.600 inches, with a +.100 inch over size.
Constructed from XH-432 XtremeAlloy for extreme heat and force resistance.
Features chrome stems and hard tips for exceptional longevity and wear resistance.
Swirl polished under head areas improve airflow into the combustion chamber.
Fully machined combustion faces enhance combustion efficiency.

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About this part

Product Details

These Manley Extreme Duty Stainless Steel Exhaust Valves are built with XH-432 XtremeAlloy, a material chosen for its exceptional strength and heat resistance. They measure 1.600 inches in diameter and are +.100 inches over standard size, meaning they are intended for engines that have been machined to accept larger valves. This specific alloy and sizing are critical for applications that experience extreme forces and high temperatures, such as Top Fuel and Funny Car drag racing, or high-performance marine engines.

Beyond the advanced XtremeAlloy, these valves feature chrome stems and hard tips. This construction detail is important because it significantly boosts longevity and wear resistance, especially in demanding environments where components are under constant stress. The under-head areas are swirl polished, which helps to smooth airflow into the combustion chamber, while the fully machined combustion faces ensure optimal efficiency. These features work together to improve how efficiently your engine breathes and burns fuel.

This set includes eight valves, making it suitable for most V8 engine configurations. If you're building an engine for extreme competition or a high-output marine application where reliability under severe conditions is paramount, these Manley valves are a solid choice. Always ensure your cylinder heads have been properly machined to accept the +.100 inch over size before installation.