Since 1939, KPMI® has taken great pride in our ability to design innovative performance improvements for valvetrains. This innovative ability has never been more apparent than with the development of the high tech lightweight racing valve spring kits for the incredibly stressed and torturous environment in today’s high revving 4-stroke engines. The challenge to engineer a valvetrain that would outperform OEM systems, that in some cases included titanium components, was not an easy one. This task would require the concentrated efforts of every member of KPMI®’s design team. It was apparent early on that an OEM style spring with a bit more pressure was not going to be the complete answer for these engines. Working together as a team enabled KPMI® to evolve with a “unified system” approach. In fact, these innovative high performance lightweight valve spring kits, would not only outperform factory parts, but outlive them as well. Each KPMI® spring kit is designed for its specific application, taking into account several critical parameters including; cam profiles, harmonics, natural frequency of the springs, valvetrain mass, required pressure, wire stress, fatigue life, and engine rpm, just to name a few! Today KPMI® proudly offers complete high performance lightweight valve spring kits for a host of applications.
We choose to use the copper based C63000 nickel-aluminum bronze as a material to make our bronze valve guides because of its ideal characteristics for the application. The 5% nickel content provides superior resistance to wear, and the approximately 80 percent copper content delivers outstanding heat conductivity. KPMI® guide profiles are designed to have minimal effect on the airstream while maintaining critical cross sectional thickness in high temperature areas, which promotes high performance and endurance.
All KPMI® Black Diamond™ Stainless steel valves are impregnated by a special German process to a depth of .002, with a surface build up of .0002. This Black Diamond process improves wear properties, reduces friction, and provides resistance to corrosion and wear that is superior to chrome and nickel electrolysis plating. Each valve is designed using Finite Element Analysis software, and profiles are tested on our computerized flow bench. Black Diamond Valves are lightweight, strong, one piece forgings with profiles that provide excellent flow characteristics.
KPMI® Shim In Tappet Valve Spring Kits and White Diamond® Valves for Various Applications
KPMI® shim in tappet systems locate the adjustment shim in the hardened steel of the tappet body, where it is impervious to wearing (ovalling) and kicking the shim out. By designing the tappet and Titanium or H.T. Steel retainer together as a system, the shim counterbore depth in the tappet has been maximized. This allows for increased insurance against losing the shim even in the event of valvetrain separation during severe operating conditions, over-revs, or extreme boost pressures.
Inconel® is classified as a “Super Alloy”, meaning that it is designed to survive under the most extreme temperatures and pressures where other valves will begin to burn, corrode, or completely fail. This is the material of choice for high output engines running turbos, superchargers, nitromethane, or nitrous.
To learn more about these Kibblewhite® Shim in Tappet Valve Spring Kit and other valvetrain related components for the various models, go to
KPMI® has developed a Beehive Spring Kit and 3 Dual-Spring Kits for the 2011-’16 Polaris XP900/1000’s and 2 Dual-Spring Kits and a Beehive Kit for the 2013- ’20 900/1000’s. Being at the forefront of valvetrain development in the side by side market, KPMI® takes pride in being able to development spring kits for the top engine builders around the world. Because of this fact, KPMI® processes valued feedback when offering new designs or modifying existing. Pay close attention to the pressures and retainer material offered. KPMI® recommends heat-treated-steel-retainers for all endurance applications and leaves it up to the most experience engine builder to select titanium retainers when mass reduction is imperative and normal maintenance teardowns are routine after each race. As an additional note, our race customers are using less open pressure for the Turbo’s and only using the Beehive and higher open pressure with experience and knowledge of the treatment of mating parts, clearances and oils. Matching a spring design to given valvetrain mass and cam dynamics is a science and when in doubt you must confer with an experienced builder.
To learn more about these Kibblewhite® Valve Spring Kits and other valvetrain related components for the various models, go to
2nd Round Top End Service Kits - Stainless Conversion for Various Honda® and Suzuki® Applications
ALL KIT CONTENTS
• High Compression Racing Piston with Coated Skirt (with rings and pin)
• Top End Gasket Kit (Head Gasket, Base Gasket, Exhaust Gasket, Cam Chain Tensioner Gasket, Valve Stem Seals, Cylinder Head Drain Seal)
• Std. Black Diamond™ or White Diamond® Stainless Valves
• Lightweight Racing Spring Kit (Titanium Retainers, Dual Springs, H.T. Steel Basewashers)
• Designed specifically for the performance demands of popular racing MX Bikes and Quads.
• Pistons designed to maintain the stock compression after the effects of the dished stainless valves
• 2618 Alloy Fully CNC Machined Piston with performance skirt coating
• Black Diamond™ and White Diamond® Stainless Steel Conversion system significantly increases valve durability
• Lightweight Racing Spring Kit Compatible with high performance cams
• All of the gaskets, rings, pins and seals required for a top end rebuild
IMPORTANT NOTE: The piston, rings, valves and pin clips in this kit are designed to work together as a system. They are NOT COMPATIBLE with O.E.M. components and should ONLY be used with the components in this KPMI® Top End Service Kit.
KPMI® H.T. Steel Cylinder Kits for Various Honda® and Yamaha® Applications
• Nuts are machined from billet high tensile steel and heat treated
• Studs are heat treated 180,000 PSI aircraft alloy steel
• Both nut and stud have rolled threads for the strongest possible threads
• Both nut and stud are black oxide treated for enhanced corrosion resistance
To learn more about these Kibblewhite® H.T. Steel Cylinder Stud Kits and other valvetrain related components for the various models, go to
• Dimensionally identical to O.E.M. valves while offering many advantages
• One piece forged Titanium alloy offers uninterrupted grain flow
• Superior tensile strength and stability at and above operating temperatures
• Every surface either fully CNC machined or precision ground
• Super-finished stem allowing for Formula 1 level coating consistency
• 100% Chromium Nitride (CrN) PVD coated
• Material and workmanship that provide outstanding durability and performance
• Competitive pricing allowing for a value conscious rebuild
Guides, +0.025", Mag. Brz, Av&V Style for Various Harley-Davidson® Applications
These Engine Builder valve guides have been designed with the price conscious builder in mind. Expect the same exacting KPMI® tolerances, but with a reduced toughness / wear-ability when compared to premium C630 Nickel Aluminum Bronze valve guides. The softer Manganese guides are easily reamed, and then can be delicately finished with our high quality ball hones. Now, with any battery operated or electric drill you can ream and hone manganese valve guides in less time and in the absence of expensive honing equipment required to properly size tough Nickel Bronze guides.
To learn more about these Kibblewhite® Valve Guides and other valvetrain related components, go to
Harley-Davidson® Evolution™ 1984-1999
Guides, Mag. Brz, Av&V Style for Harley-Davidson® Milwaukee-Eight™ 2017-2020
• Valve guides for HD® M8 Application offered in Manganese Bronze to achieve an extremely competitive price point.
• KPMI® Manganese Bronze guides, are able to be sized by reaming, using KPMI’s line of precision valve guide reamers
• Now with any battery operated or electric drill you can ream HD® valve guides in less time and in the absence of the
expensive honing equipment required to properly size “tough” Nickel Bronze guides.
To learn more about these Kibblewhite® valve guides and other valvetrain related components, go to
Harley-Davidson® Milwaukee-Eight 2017-2020