Spring. Valve. Performance race kit. 40PSI at full cam lift.
Compatible with Honda YX140 Lifan based heads.
For use with performance cams with 7mm or under extra valve lift.
Springs are 30% stronger to avoid valve bounce and piston collision.
The kit consist of 4 springs to complete one 2 valve engine build.
Perfect for Z40 and NBR cams FAST ROAD
At 22mm compression = 40PSI
To increase the PSI use our 1.9mm shim under the valve spring
VALVE SHIM