I was readinga story onone of my old Chevy High Performance magazines explaining camshaft basics c/o an expert from Comp cams. He states that one of the crucial reasons to buy matching springs to a cam is that the spring actually vibrates as it compresses. I alway thought youwanted a good spring for proper load as to not float on high rpm. What I don't understand is at what point does it so called vibrate and create a resonance? how does it if any reduce performance? Is this what the inner damper is for on stock springs? I've never built a race engine, just basic overhauls to revive tired daily drivers so thesearticles are alittle confusing for me. Thanks for any replies.

 

im no comp cams engineer, but from what I know of physics and the workings of the valvetrain, the resonance is float. (someone can correct me if im wrong) but as the rocker pushes down the spring has only one direction of travel, only one force applied to it from its resting state, and in order to vibrate, it must generate a force within itself greater than the force of the rocker and in the same direction as the rocker force. this force will cause it to leave the rocker until the opposing force generated by the compressing spring is greater than in sending it back up, in this way causeing it to vibrate as it travels against the rocker. this is pretty absurd i think.

however, a common issue is the spring "bouncing" as it slams shut, as well as the lifter hopping off of the cam lobe. both of these things happen at high rpm if the spring isnt strong enough to keep the lifter on the cam, and the valve from bouncing off of the head, and both of these things contribute to valve float.