We are manufacturer of Engine valves for all kind of Gasoline, Diesel and Industrial IC Engines. Normally, a valve should rotate during engine run. Rotating valves have high life certainly. Rotating valves have high life certainly. Uniform heating of valve seat surface (means no heat collections local heat areas ), preventing of some carbon adhesions, valve train disturbances and good running surface on the valve tip depend on the valve rotation. Rotating event, if no rotator mounted, happens by normal vibration of engine and also spring strok. The valve do not rotate by deformed or not good weak springs. Valve should be rotated normally, no fast or no slowly. Good springs and rotator (rotocaps) result in normal rotation of valve and no we