Description Reviews Supertech MINI Cooper Beehive Valve Spring Kit. Fits all MINI Cooper S with N14 or N18 motor. Make sure you pair it with all of the other Supertech items like the valve kit N14 or N18, valve seals and valve guides! Beehive Valve Spring Kit Type: Beehive Spring SeatPressure: 70lbs @ 33.60mm installed Height Max Net Lift: 11.40mm Spring Coil Bind: 22.20mm Rate: 9.70 lbs/mm Retainer: Titanium Retainer RET-MC56/T1 Spring : SPR-MC56BE