Honda 450cc Valve Spring Information (TRX450R, 02-08 CRF450R, and 05-17 CRF450X)
Posted by JSD Machine Works on Mar 28th 2020
Valve Springs are very important item in the engine. They are in charge of controlling the valve and keeping the motor from suffering damage. We will look at the Valve Spring Specs for the Honda 450cc MX and ATV Engines. These specs are very important when it comes to choosing valve spring for your engine.
OEM Valve Springs:
We generally do not use or recommended using OEM valve springs in any Honda 450cc engine. but you can use them in engines with stock cams and not have any issues with them. In a pinch, you could run these springs with Hot Cams Stage 1 and Stage 2 Cams, but it is not recommended.
Kibblewhite Valve Springs:
These Valve Springs are recommended by us, as well as most other engine builders and they work with most cams for the 450cc Honda engines. These springs are a heavy duty dual spring setup, and are good for oversized stainless steel valves with some bigger cams.
Part #'s: 04-05 Honda TRX450R: 111-006-118-VCH87
06+ TRX450R/ER / 02-08 CRF450R / 05-17 CRF450X: 112-006-118-VCH74
Max Valve Lift: These springs are good to .440" of Valve Lift on the intake and exhaust springs
Retainer to Valve Seal Clearance: the Titanium Retainers included in this valve spring kit will clear valve guide seals at valve lifts of .410" on the Intake / .360" on the Exhaust. If the Cam you are using lifts higher than these specs, you will need to change guides to shortened guides or sink the guides in the cylinder head.
Web Cams also offers High Rev Valve Spring Kits for the 04-05 TRX450R and the 06+ TRX450R/ER / 02-08 CRF450R / 05-17 CRF450X.
04-05 TRX450R Web Cam Valve Spring Kit (High Rev) (Part #:111-006-118-VCH81):
This Valve Spring kit from Web Cams is a single spring kit. It uses a single spring, like OEM to control the valves. This spring kit is designed to run a High RPM motor. We would recommend Titanium Valves with this spring kit, especially with bigger Web Cams. This Spring Kit is recommended for Flat Track and High RPM Applications. These springs are good up to 12,000 RPM.
Specs:
Max Valve Lift: Unknown.
Retainer to Valve Seal Clearance: the Titanium Retainers included in this valve spring kit will clear valve guide seals at valve lifts of .410" on the Intake / .350" on the Exhaust. If the Cam you are using lifts higher than these specs, you will need to change guides to shortened guides or sink the guides in the cylinder head.
06+ TRX450R/ER / 02-08 CRF450R / 05-17 CRF450X Web Cam Valve Spring Kit (High Rev):
This Valve Spring kit from Web Cams is a single spring kit. It uses a single spring, like OEM to control the valves. This spring kit is designed to run a High RPM motor. This Spring Kit is recommended for Flat Track and High RPM Applications. These springs are good up to 12,000 RPM. These Valve Spring Kits are not recommended with Del West Valve Keepers
Specs:
Max Valve Lift: These springs are good to .435" Intake Lift and .380" exhaust lift.
Retainer to Valve Seal Clearance: the Titanium Retainers included in this valve spring kit will clear valve guide seals at valve lifts of .410" on the Intake / .350" on the Exhaust. If the Cam you are using lifts higher than these specs, you will need to change guides to shortened guides or sink the guides in the cylinder head.
Web also offers a High Lift dual spring kit for Titanium Valves: This kit will not work with the 04-05 TRX450R.
This kit is for Titanium Valves only, will not work with Stainless valves and will likely have valve float if used with stainless valves. This kit is a recommended kit if you are using Titanium Valves and are looking for a high lift alternative to the Kibblewhite Valve Springs.
Specs:
Max Valve Lift: These springs are good to .500" of Valve Lift on the intake and exhaust springs.
Retainer to Valve Seal Clearance: Unknown.