Nascar valve spring @7000rpm

[Steve85]

This a valve spring in action at 7000rpm controlled by a .700 lift cam

http://www.youtube.com/watch?v=i_NpzU4pGjc

[ScottyB]

that's some crazy witchcraft and magic right thurr! i had always thought it was just a simple up/down thing, no extra movement. i guess that second inner spring helps keep oscillations down, which makes the physics of the whole thing even more amazing.

good grief i can't imagine an F1 spring. even a honda engine revving to 9K.....i'll just concentrate on the pretty noises they make and forget about the fact that the springs are dancing around hock:

[G.Irish]

good grief i can't imagine an F1 spring...

They don't have springs... :twisted:

[D_Eclipse9916]

The dual spring setup is so that it can control a higher lift and duration cam. I beleive that is what they are running there, but I didnt watch the video. As far as I knew about valves was that that spring was supposed to seat on the valve "seat" and the only other movement other than down and up was the spring turning on seat. I could be wrong.

[NTIman]

It is a double valvespring in the video.
The spring itself shouldn't spin much at all.

In a racing application you want to keep the valve spring pressure as light as possible to reduce power loss, but not light enough to loft the valve or float them at high RPMs.

When the valve slams shut, because of the lift and the pressure of the spring, it will bounce the valve off of the valve seat.