Valve Black Diamond™ by KIBBLEWHITE — manufacturer reference 30-30223. Exhaust valve dedicated to Cross machines, CNC machined from a monoblock forging in EV8 stainless steel to combine lightness and mechanical strength in extreme conditions.
- Construction: EV8 monoblock forging, CNC machining for optimised tulip profiles.
- Surface treatment: German process applied at .002 depth with a .0002 surface layer, designed to improve wear resistance and reduce friction.
- Stem: black nitride coating to limit wear on the guide side.
- Controlled design: profiles analysed by finite elements (F.E.A.) and tested on a computerised flow bench to validate aerodynamic behaviour.
- Application: exhaust — Tulip angle 20° (1.220 / 31.00 mm head diameter).
- Origin: made in the United States.
Designed for motocross cylinder heads, the Black Diamond™ is aimed at riders looking for machined and durable valve parts for their CRF 450 R (PE05) 2006‑2008 and other compatible machines. Note: installation requires the use of the appropriate Kibblewhite spring kit. Professional installation is recommended for adjusting clearances and verifying fit on the seat and guide.