valve springs

[Ted Hart]

Originally Posted by MetroMPG

Hmm!

Could you just shave half a milimeter off the top and bottom, where they seat, not actually affecting the spring itself?

I admit I know nothing about spring physics or metals.

Fun thinking about it though.

A slack(er) valve spring encourages ... maybe not enough ... the valve to "bounce" when it reaches the seat. This is not good! Valves are brittle; they break! A spring with a longer than valve stem length (when closed) ensures no bouncing goes on....The lobes of the cam have "ramps" ground into the profile (you'll never see 'em!) to let the valve down onto the seat...instead of just dropping it. A slight amount of spring tension is required to force the lifter / rocker arm to "follow" the lobe profile!
There is a lot going on, here!