How to Test Valve springs

[BogusSVO]

How Valve springs are checked


I had to check the valve springs for a 4G63T


This is a simple process. But a specialized piece of equipment is needed.

I use a Rimac spring tester with a 300lbs scale.

The first thing to do is set the stop to the correct height.
The spec used is 66lbs @ 1.575
I find that a venier caliper is more accurate than the built in scale.

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Place the spring to be tested in the spring tester

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Compress the spring to the pre set height and read the pressure.

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It is a quick and simple way to have your valve springs checked to make sure they are in good serviceable shape.

Low spring tensions can lead to a lazy rev of your engine and also valve float.

Most of the valve springs I tested I found to be well out of a usable spec.
Most springs I tested fell in the range of 40-55lbs @1.575
Most spring manufactures allow for 10% loss of spring pressure for spring break in.

 

[99gst_racer]

Old thread, but I have a couple questions.

When you say, "Compress the spring to the pre set height and read the pressure.", what do you mean by 'pre set height'? Is it installed height minus valve lift?

Also, do you know what the installed height is on the factory springs? And what is the acceptable pressure range for the factory springs.


It's been about 4 years since I've touched the Intercomp sping tester that we have at work, and I've only ever tested after market springs, so I'm a bit rusty.

 

[snowborder714]

I would guess the preset height to be the 1.575 he mentions at the beginning. My guess is because he says "Most springs I tested fell in the range of 40-55lbs @1.575" so I'm assuming the 66 lbs @ 1.575 is the spec you should be seeing to know your springs are in good working order.

 

[BogusSVO]

Snowboarder is correct..

you want to check the spring at both the closed height (installed height) and the open how much the spring is compressed at full valve lift.

here is a link to some valve spring info I have gathered up...

http://www.dsmtuners.com/forums/newbie-forum/341209-4g63t-valve-spring-info.html

feel free to post the specs of the valve springs you use and or the results of what you find when you test the valve springs

 

[99gst_racer]

Thanks for the info, guys.

And thanks for that link, BogusSVO.

 

[BogusSVO]

no prob.. glad the info I post is getting put to use!