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Manley 5/16 Valve Stem Wear Caps
$36.61

Manley 5/16 Valve Stem Wear Caps (Part No. 42300-8)

If you're looking to keep your engine running smoothly and efficiently, the Manley 5/16 Valve Stem Wear Caps are a smart choice. Designed specifically for high-performance applications, these caps provide excellent durability and functionality for your vehicle's valve train system.

Key Features

  • Quantity: 8 pieces per set
  • Stem Size: .3110" (5/16")
  • Minimum Tip Diameter: .250"
  • Type: Non-Rotating
  • Dimensions: A: .210", B: .080", C: .425"
  • Material: Thru-hardened 4140 alloy steel
  • Heat Treatment: Special treatment to achieve HRc 50-54
  • Benefit: Non-rotating design minimizes valve tip erosion

Why Choose Manley Valve Stem Wear Caps?

The Manley 42300-8 caps are engineered to withstand the rigors of high-performance engines. Their non-rotating design helps reduce wear on the valve tips, ensuring your engine maintains optimal performance over time. Made from high-quality 4140 alloy steel and treated to achieve a hardness rating of HRc 50-54, these caps are built to last.

Specifications at a Glance

When it comes to specifications, these caps are designed to fit a variety of performance applications. The dimensions and materials used ensure that they can handle the demands of both street and race engines alike.

Fitment Information

The Manley 5/16 Valve Stem Wear Caps are compatible with a range of vehicles that require 5/16" valve stems. Always check your vehicle's specifications to ensure compatibility before purchase.

Customer Reviews

Customers have praised the Manley 42300-8 Valve Stem Wear Caps for their quality and performance. Many users have noted a significant reduction in valve tip wear after installation, leading to improved engine longevity and reliability. Here’s what some satisfied customers had to say:

  • "These wear caps fit perfectly and have greatly reduced wear on my engine's valves!"
  • "I noticed an immediate improvement in performance after switching to these caps. Highly recommend!"
  • "Great quality and fit. A must-have for anyone serious about their engine's performance!"

Upgrade your engine's valve train with the Manley 5/16 Valve Stem Wear Caps (42300-8) and experience the difference in performance and durability.

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How did Manley Performance Start?

Manley Performance, formerly called Manley Speed Equipment, was established in 1966 by Hank Manley shortly after his graduation from Brown University. His interest in the performance and racing traced back to 1960 when, at age 17, he rebuilt a 312 CID Ford V8 engine, installed a camshaft and three two-barrel carbs, and raced a ’56 Thunderbird on New Jersey’s streets. Initially, the company’s product lineup included stainless valves, lifters, camshafts, forged pistons, vanadium valve springs, pushrods, and timing chain kits. By 1998, Manley had outgrown its first Bloomfield, New Jersey facility and bought several acres in Lakewood, New Jersey. It was around this time that the brand’s name formally changed to Manley Performance. Nearly a decade later, the production space doubled in size.

Evolving in the Automotive Space

Led by GM Michael Tokarchik in 2002, Manley entered the high-performance passenger car market as an OEM supplier of connecting rods for the 2003/2004 Ford SVT Mustang Cobra. Production reached 2500 rods per week without missing a single delivery date. Ford awarded Manley its highest ever supplier rating. Manley’s presence in the OEM market continued from there as a supplier for the Ford GT. After nearly 50 years since its inception, Manley continues to be globally recognized as the leading manufacturer of performance valves, connecting rods, cylinder head components, pushrods, drive and oil systems, and several other engine parts.

What is Manley’s Specialty?

Manley Performance specializes in high-performance engine internals that range from stock replacements to full-on race applications. They have been the standard of the industry since their inception; a fact that still remains true now as they have ventured into new markets. Today, Manley Performance continues to re-define itself in a high-performance aftermarket industry that is constantly evolving. The brand has developed a wide range of new products for growing markets that include sport compact, Ford modular, and Chevy LS. Manley also maintains its leadership role with the traditional V8 engine business.

Get Manley Performance at Vivid Racing

If you are in need of a serious upgrade to your engine, then Manley Performance parts should be on your list. Like all of our suggested manufacturers, Manley uses the best materials available to ensure a quality part for your engine. We carry Manley connecting rods, crankshafts, pistons, and valve components. The large lineup of domestic parts includes sport compact vehicles, Ford modular engines, GM’s LS series internals, and HEMI product upgrades for Chrysler.

If you can’t find what you’re looking for or need help choosing the right part for your car, call our sales team at (480) 966-3040. We are here to make your buying experience a breeze.

Due to the intended usage of the products sold by Manley Performance Products, Inc., they are sold WITHOUT WARRANTY OR ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR THE INTENDED PURPOSE. Manley Performance Products, Inc. shall not, under any circumstances, be liable for any special, consequential or incidental damages, including but not limited to loss of profits or revenue, loss of other property or equipment, cost of purchased or replacement of goods, or claims by customers of the purchaser, which may arise and/or result from the sale, installation or use of these parts. Installation of parts intended for “off-highway” use could adversely affect the vehicle manufacturer’s warranty coverage. Subject to applicable state law. Some items may not be legal for use in California on pollution controlled vehicles. All weights specified are approximate and subject to manufacturing tolerances. Manley Performance Products, Inc. reserves the right to make changes in design, specifications, materials, or make product changes without incurring liability or obligation with respect to similar product previously manufactured. If technical advice is offered or given in connection with the use of any Products it will be as an accommodation to Buyer and without charge and Seller shall have no responsibilities or liabilities whatsoever for the content or use of such advice.

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