Manley Performance NexTek Series .580" Lift High Performance Valve Springs | Multiple Fitments (221433-24)

Ford 4.6L, 5.4L 3 Valve NexTek® Series High Performance Valve Springs - Set of 24 by Manley Performance

These Manley NexTek valve springs are better-designed valve springs using state-of-the-art machinery for purpose-built racing engines. They're manufactured from super-clean, high-tensile chrome silicon steel and are shot-peened to MIL specs for maximum fatigue life. They feature a proprietary, multi-step heat-treating that minimizes load loss and have computer-aided modeling to minimize valve bounce and valve gear separation.

The Manley NexTek valve springs are smaller diameter and lightweight, allowing engines to rev higher faster. They have an extended tip thickness designed to eliminate overload breakage, and their tightly controlled open-end flatness reduces valve stem side loading.

Features

• Manufactured from “super clean” Hi-Tensile Chrome Silicon steel
• Tip thickness designed to eliminate overload breakage
• Shot-peened to MIL spec for maximum fatigue life
• Computer-aided modeling or designs minimizes valve bounce and valve gear separation
• Tightly controlled open end flatness reduces valve stem side loading
• Proprietary multi-step heat treating minimizes load loss
• Optimized “Select Size Fitting” between outer and inner springs to maximize harmonic dampening and reduce heat generated during operation
• Many offerings are a damperless design which eliminates unnecessary damper weight and reduces retainer wear

Benefits

• Higher natural frequency and lower active mass provides improved valvetrain control and higher RPM potential
• Dual spring design reduces friction, which generates less heat and translates into greatly reduced load loss
• Extensively tested on the Spintron, dyno and race track (including blown nitro engines) and proven highly effective
• Smaller diameter, lightweight dual design allows engine to rev higher with improved valve train control
• Accepts smaller, lighter retainers which also promotes higher revs
• Ultra clean, high tensile strength chrome silicon material
• Super Finished multi-step surface enhancement significantly improves fatigue strength
• Ideal loads for multiple applications with minimal load loss

Please Note: These Chrysler Hemi springs come with shims which are ONLY needed for 6.1L applications on the intake side in order to achieve the correct installed height. Each set also includes a set of piloting rings that install over the factory “Top Hat” integral valve seal to properly locate the ID of the spring on early 5.7L (thru 2008) and 6.1L applications

Applications

• 2005–2010 Ford Mustang GT
• 2008–2009 Ford Mustang Bullitt
• 2006–2010 Ford Explorer
• 2004–2010 Ford F-Series
• 2005–2014 Ford Expedition
• 2005–2014 Lincoln Navigator

What's In The Box?

• 24 - Valve Springs

Warranty

• Manley products, due to their intended use, are sold without warranty.