upertech Black Nitrided Intake and Exhaust Valves STD. size - Other sizes and styles of valve available upon request, email us before purchase for details
Part Numbers: HIVN-1012 / HEVN-1012
Swirl Polished
Undercut Stems
Backcut angle for better flow
Hardened Stem Tips
Black Nitride Coating is a hardening treatment that even though it is not as widely used as the chrome plating, it has several benefits and has become more popular for use in the European and Japanese applications.
Benefits of Black Nitride Coating:
The micro hardness is higher than the stainless steel base material, keeping good ductility beneath the hard nitrided layer (micro hardness is 800HV minimum)
Valve seat surface is harder with the nitrated layer, lasting longer with lead free fuels, alcohols, nitro, or other "explosive" mixes. Matches any kind of seats (nodular iron seats, steel powder metal seats, hard aluminum-copper seats or beryllium copper seats).
Higher rpm engines take full advantage of all the previous features. The higher the engine speed the bigger the power loss due to internal engine friction! The black nitride layer reduces this power loss due to less valve-guide friction.
The nitrided layer is adhered to the base material at a microscopic level, so it will not "flake" or bake when the valves bend due to impacts with the pistons
The Black Nitride applies to the whole valve while the chrome coating is only applied to the stem.
All valves are swirl polished, have stem undercut, a hardened tip and more.