Valve spring ?

[ikle]

How important is valve spring pressures ? I have been doing some reading and it seems that some people buy a particular valve spring and install them as is and some check the springs pressure and shim them to achieve a desired pressure. Does it make a huge difference in how the motor runs ? Which is the desired method ? Thanks, Kyle.

 

[earlbrown]

It can make the difference between running correctly and the valvetrain coming apart.

The correct way is to shim the springs to the desired poundage and give the valvetrain what it needs to do the job.

In the case of just shotgunning a spring out of a catalog... that 'works' because of thousands of previous trial and error that gets it pretty close. The other factor that helps the 'easy way' is that the stock springs are soooooooooo far off from optimal, when you change springs you don't have to get it perfect to end up much better off.

 

[GNONYX]

I was doing some homework and read this thread, but now I have some questions for you mentors out there
One talks about when replacing valve springs one should check the valve spring height micrometer accurately measures the distance between the valve spring seat and retainer. Is this true even for direct replacement valve springs?

The You Tube video shows that individual didn't use the tool since he claimed it was a direct replacement valve springs.
http://www.turbobuick.com/forums/threads/valve-spring-replacement.386189/

Also claimed to use air compressor in the cylinder to keep the valve up where others claimed to put rope inside the cylinder.
Is it best to for both application to keep that individual cylinder in the up stroke position just in case if anyone of the application fails to prevent the valve from falling into the cylinder head?

 

[bison]

I was doing some homework and read this thread, but now I have some questions for you mentors out there
One talks about when replacing valve springs one should check the valve spring height micrometer accurately measures the distance between the valve spring seat and retainer. Is this true even for direct replacement valve springs?

The You Tube video shows that individual didn't use the tool since he claimed it was a direct replacement valve springs.
http://www.turbobuick.com/forums/threads/valve-spring-replacement.386189/

Also claimed to use air compressor in the cylinder to keep the valve up where others claimed to put rope inside the cylinder.
Is it best to for both application to keep that individual cylinder in the up stroke position just in case if anyone of the application fails to prevent the valve from falling into the cylinder head?

It is very important to measure to know the measured installed height and pressure @ height . There are a lot of things that can vary installed height. I've always used air and have never dropped a valve. I've probably done 300-400 valve springs with the engine in the car. Anything not checked can never be eliminated as a potential issue in the future when the engine doesn't respond

 

[ikle]

It is very important to measure to know the measured installed height and pressure @ height . There are a lot of things that can vary installed height. I've always used air and have never dropped a valve. I've probably done 300-400 valve springs with the engine in the car. Anything not checked can never be eliminated as a potential issue in the future when the engine doesn't respond

So Brian what tools are needed to measure the installed height of a valve spring ? Also if you purchase a spring that is advertised at lets say 92lbs @ 1.70 installed height is there a need to check them or are they usually within specs when purchased new ?

 

[TurboTdr3.8]

I always use air to hold the valves on the car , plus just because the advertized specs say something , you still check them and then you will know what they are , they can vary several lbs from spring to spring , I learned the hard way but with the tools you can do it right the first time and no guessing . It does make a difference .

 

[ikle]

I always use air to hold the valves on the car , plus just because the advertized specs say something , you still check them and then you will know what they are , they can vary several lbs from spring to spring , I learned the hard way but with the tools you can do it right the first time and no guessing . It does make a difference . View attachment 212157 View attachment 212158

Where's the best place to purchase these tools ?

 

[TurboTdr3.8]

Summit Racing

Posted from the TurboBuick.Com mobile app

 

[GNONYX]

It is very important to measure to know the measured installed height and pressure @ height . There are a lot of things that can vary installed height. I've always used air and have never dropped a valve. I've probably done 300-400 valve springs with the engine in the car. Anything not checked can never be eliminated as a potential issue in the future when the engine doesn't respond

Thanks for fast response Bison,
Being you have replaced that many valve springs, what type of valve springs would you recommend for a stock engine?
I heard comp 980 aren't that good, noisy. Then again everyone has many opinions, but for yourself of doing that many which one?

 

[earlbrown]

It's the Comp lifters that are known to be noisy. If a spring is making noise, you're already in trouble!!


Based on my personal first hand experience, don't trust the published spring specs.

 

[turbo89]

So Brian what tools are needed to measure the installed height of a valve spring ? Also if you purchase a spring that is advertised at lets say 92lbs @ 1.70 installed height is there a need to check them or are they usually within specs when purchased new ?

you will find some springs are a lot closer to advertised than others... also .. whatever you do ... DONT OVERSPRING THE CAR !!! they don't need it !!

 

[GNONYX]

It's the Comp lifters that are known to be noisy. If a spring is making noise, you're already in trouble!!


Based on my personal first hand experience, don't trust the published spring specs.

Hey earlbrown you're right, I was thinking about the comp 980 lifters and then started to write about the valve spring. That 's what happens when you start to muti-task the thinking, I got to stop doing that.

 

[Wahoo]

I'll need to replace mine this spring.

 

[1KWIKSIX]

Can anyone post a link on where I can purchase valve spring shims?
Need an assortment of a few in varying thicknesses (in thousands of an inch) in order to get my springs specs consistent.

Thanks in advance.

Dave

 

[TurboTdr3.8]

These might work , need to take measurement to make sure or call their tech support , http://www.summitracing.com/parts/cca-4756/overview/

 

[getchasum]

If doing a stock un-open engine Comp 979's or 980's is all that is needed. Be sure not to reuse the stock cups.

 

[GNONYX]

If doing a stock un-open engine Comp 979's or 980's is all that is needed. Be sure not to reuse the stock cups.

I was reading on some threads where comp 980 were noisy, anyone has the same issue or are they quiet?

 

[ikle]

I was reading on some threads where comp 980 were noisy, anyone has the same issue or are they quiet?

Re-read post #10

 

[GNONYX]

Re-read post #10

Thanks, but if the Comp 980 are noisy then what type of lifters are quiet?

 

[earlbrown]

Morels are the quieter of the two. The still have to be set up with the correct length pushrods to work correctly and quiet.. The length will be different than the ones used on the comps as the lifter cups are at a different height.