Description
DEF Racing 2017-2026 HONDA CRF450R high-performance +2.0mm oversize steel exhaust valves and +2.0mm oversize titanium intake valves. We highly recommend using these valves with larger cylinder bores and a properly ported head. Primarily used for Flat Track, Drag Racing & Hill Climb racing with the focus of delivering significant gains to top end power.
Sold as a complete set of 4 valves!
Product Features:
- Exhaust Valves: Increased diameter to 33.0mm (+2.0mm larger than OEM) – Steel
- Intake Valves: Increased diameter to 40.0mm (+2.0mm larger than OEM) – Titanium
- Requirements!
- Will require machine work to remove and reinstall larger “intake” valve seats
- Must use at least a 40.5mm intake valve seat
- Requires a piston with increased valve pocket diameters!
- Will require machine work to remove and reinstall larger “intake” valve seats
- Valve Stem Size: Remain OEM of 5.0mm
- Material: Manufactured in the USA with high-quality steel and titanium for exceptional strength and longevity
- Design: Proprietary tulip and margin shapes specifically designed to improve airflow, reduce reversion and turbulence
- Durability: Hours of testing and racing have proven to be extremely durable
For the best results, we recommend using this valve kit with a properly ported head, larger bore and throttle body to fully unlock its potential.

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