OK, engineer here. What you are seeing in the video is not valve float - the title is wrong. Valve float is when the RPM of the valve train is so high that the spring does not have time to extend fully before the cam comes down again. IF this was valve float, you would see a video of a compressed spring that never seems to move back to its uncompressed state. What you ARE seeing is valve bounce, where the inertia developed by the cam is so high that the valve unseats itself slightly every stroke. Valve and spring rotation is normal at these RPMS. Finally, AlixHAF is correct - the reason it looks like the image is 'frozen' is because of the sampling rate of the video relative to the RPM of the vehicle, in the same manner that car rims sometimes look they're not moving in a video. It is based upon a part of signals theory called Nyquists Theorem, which I won't detail here but you can look it up if you're interested. Hope this clarifies things.
Amazing video!! Great job! I never thought there was that much flex in the valve stem itself! And the rotation is interesting also!! Thanks I really learned something and I will remember what I learned and apply it toward my next engine build!!!!!!!
Amazing Video!!!!! This should help many people understand what's going on with their Valvetrain. The use of fast ramp rates just exacerbate the valve float problem. Better springs and lighter parts ie Valves, Retainers, Locks etc should alleviate the problem Thanks for the great Video!!!!
Valve float happens when the cam profile is too aggressive for the valve spring rate. The higher the lift, the stiffer the spring you have to use. Some people have the misconception that roller lifters add power.. but in reality it's just to alleviate friction from running super stiff valve springs.
