THE SPRING OF VALVE SPRINGS.

Press, Volume LXIX, Issue 20919, 28 July 1933, Page 7

THE SPRING OF VALVE SPRINGS.

A HARD-WORKING I'AKT. The improved performance of new valve springs is sometimes remarkable. This is not surprising when it is realised the tremendous work that such a spring is required to do. Ten thousand miles of driving means 100,000,000 cycles of operation for the valve springs—hard, continuous, racking work. Valve springs are said to work harder than any other part of the automobile. They must operate at high speeds under heavy pressures. They receive terrific shocks and are subject to split-second reversals of motion while being treated to a wide variation of temperatures. All of these conditions are responsible for eventual loss of "springiness" and strength. The metal of which the spring is composed loses its temper and becomes fatigued or breaks. This loss of springiness or resiliency will result in a loss of power, engine overheating, and back-firing at other than low speeds, due to failure of the spring to hold the valve lifter follower tightly on the cam. If the valve does not follow the contour of the cam closely the valve timing may be inaccurate. The result may be to hold open both the valves at the same time, thus interfering with the proportions of the mixture and causing back-firing. Loss of valve spring strength also means valve damage because the valve is not held tightly on the seat long enough to cool the valve head. The overheated valve will cause preignition, noise and other defects ia operation.