Colin Wood
Colin Wood Associate Editor
10/18/21 11:34 a.m.

https://www.youtube.com/embed/WtqDHJDN79w

What does a valve spring look like when it's operating at 8500 rpm?

Thanks to the magic of slow motion, we can see that valve springs move around quite a bit.

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Ed Higginbotham
Ed Higginbotham UberDork
10/18/21 12:01 p.m.

That is SUPER cool to watch

GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
10/18/21 12:23 p.m.

Way more jiggly slinky action than I expected, and that's a dual-spring setup!

bgkast
bgkast GRM+ Memberand PowerDork
10/18/21 12:24 p.m.

The algorithm suggested this one to me a few days ago too. laugh

RadBarchetta
RadBarchetta New Reader
10/18/21 1:15 p.m.

In reply to bgkast :

All hail The Algorithm.

Colin Wood
Colin Wood Associate Editor
10/18/21 3:19 p.m.

In reply to GameboyRMH :

Exactly why I felt the need to share, definitely a lot more movement than I would expect from a valve spring.

Colin Wood
Colin Wood Associate Editor
10/18/21 3:19 p.m.

In reply to bgkast :

Looks like we both have good taste in YouTube videos.

BA5
BA5 GRM+ Memberand Reader
10/18/21 4:54 p.m.

Lotus has a piece of software that calculates the motion of all the individual coils of a valve spring, since that's pretty critical to determining valve float.

CyberEric
CyberEric Dork
10/18/21 5:23 p.m.

Wow! So much jiggle and so much rotating! 

RichardNZ
RichardNZ GRM+ Memberand Reader
10/18/21 7:06 p.m.
CyberEric said:

Wow! So much jiggle and so much rotating! 

As the bishop said to the actress smiley

wako29
wako29 GRM+ Memberand New Reader
10/19/21 8:53 a.m.

Can someone please explain why it's rotating so much? I'm genuinely curious and can't really figure it out. I assume vibration but then why wouldn't it just find the 'heavy' end of the spring and stay there?

frenchyd
frenchyd UltimaDork
10/19/21 12:14 p.m.

In reply to Colin Wood :

Think of the energy lost with the weight of the lifter, pushrod, and rocker arm.  In a typical pushrod engine.  
  Compare that to an overhead camshaft that acts directly on the valve. 

jfryjfry
jfryjfry SuperDork
10/19/21 9:48 p.m.

I'm surprised also at how much the valve moves axially.  Very cool

BA5
BA5 GRM+ Memberand Reader
10/20/21 8:16 a.m.
wako29 said:

Can someone please explain why it's rotating so much? I'm genuinely curious and can't really figure it out. I assume vibration but then why wouldn't it just find the 'heavy' end of the spring and stay there?

It's rotating because when you compress a spring there's a 'twist' (moment about the axis of the spring) component to the force as well as the axial force.  All the little vibrations of the individual coils also impart this twisting force.

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