[Christ]

But the spring is pushing against a rotating object, which, at speed, is probably rotating away from the spring close to the same speed that the steel spring can return to original form, not to mention the lack of force application, since the force of the spring is pushing back against the can at close to the cams center line, or with rocker type valve trains, pushing against a lever which rides near the center line of the cam. Applying linear force to a rotating object without leverage in the direction of rotation? Sore, that's a winner...