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Discussion Starter · #1 ·
Does anyone know how much variation is tolerable for the valve spring installed height? Stock requires 1.385" from valve seat (valve seat shim) to the bottom of the retainer.

After some measurements, I noticed that each valve has varying retainer heights when installed on the valve. Seems as if some retainers sink a bit more into the valve locks than others (this is all Ferrea hardware BTW). I measured variances of almost .020".

I can measure every single valve/retainer/lock combination and come up with a range, but most places (Silver seal) offer valve seat shims in .015, .030 and .060, thus I'm not sure if I should leave the OEM .020" shims in place and not worry about the variations.

The real question: Does anyone even worry about these heights after doing basic valve jobs?
 

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I do. I didnt check all of them like you did, but to see a span of .020, thats alot. I think more important that installed hiegth, is installed seat pressure. I did the BC kit and it called out 85lbs pressure. So I got my scale out and measure what it took to get 85lbs, then shimmed that way. I needed .050 total shim to get that. I forget what the spread was, but .020 could make a difference. have you machine shop test a few springs at the installed and move it .020 and see.

On another head I did, (non toyota) drop in springs were only seated at 60lbs. Thats when I learned more about all this because of the 7k rev limit! I shimmed them on the next build of the head and could rev to 8500 no problems.
 

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Discussion Starter · #3 ·
I have one valve that needs .019" shim to bring it to the nominal OEM valve height length, and another valve that only needs .001". I did my own valve job on this head so it is possible the variation is due to my inconsistencies. Bascially, if I use the OEM .020" shim, I will be compressing every spring a few thousands than it needs to be, one by as much as .019".

So, that one valve would have the highest spring pressure. If the more pressure the better (up to a point), then I may just leave it as it is. I read that +/- .015" is typical acceptance variation for installed spring height - to - spring pressure. Speaking to Greg @ GSC, he mentioned staying close to OEM installed height spec but didn't discuss acceptable tolerance.
 

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Thats good to know on the variance. Would be interesting to see the differnces on a spring scale just what .020 gives you.
 

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Hmm. When i did my head i just ignored spring height and did valve lash like normal. Wouldnt spring height be adjusted for by that anyway? I also didnt bother with spring seat pressure because it was a brand new gsc beehive set but i definitely would if re-using old springs.
 

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Discussion Starter · #6 ·
Thats good to know on the variance. Would be interesting to see the differnces on a spring scale just what .020 gives you.
Something I gotta go to GSC for. Not necessarily the measurement itself, but what is the maximum spring pressure I should avoid to prevent seat damage or other artifacts. This may be something only GSC could answer since they should have the R&D data on these Beehive springs.

I have every tool at my possession except the valve spring compressor!
 

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Any spring setup should be checked, just like all cams should be degreed. Tolerances all around can make them loose or tight. To low of a seat pressure will cause premature valve float and to high can cause bouncing too and if the open pressure is to high, can wipe the cam lobe out. Most likely not the case, most of the time seat pressure is low and shims are needed. And adjusting the valves does not affect the spring seat pressure.
 

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Hmm. When i did my head i just ignored spring height and did valve lash like normal. Wouldnt spring height be adjusted for by that anyway? I also didnt bother with spring seat pressure because it was a brand new gsc beehive set but i definitely would if re-using old springs.

No no no, those are completely two different things. Spring height/pressure are from the base spring perch of the head, to the bottom of the retainer when it's held on place by the lockers. The shimming for lash is between the tip of the valve stem and the cam at its base circle. They can be adjusted completely independently and both should always be checked.

Valve spring height/pressure should be checked if its a brand new spring or a 200k mile spring. The lash should theoretically never change unless you change cams, valve seats, or the valve itself.
 

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Old thread bump - where do you order the valve spring shims? NOT talking about shims for the buckets for valve lash.
 

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Adding my learnings: the OEM shims are 0.020 as indicated above and only come in that size. There may be other generic shims that fit the small OD of the 2JZ head but it is not an off-the-shelf 2JZ specific part.

It is better to be tight (less than specified spring install height) rather than loose on the installed spring height so long as you are not pushing the spring towards its coil bind limit with the cam lift profile you are using.

E.g. if your spring installed height is measured at 0.015 higher than the spring manufacturer's specified installed spring height, you are better off adding a second 0.020 OEM shim under that spring to achieve 0.005 less than the spring manufacturer's installed height specification.

It is better to have a bit more preload on the spring (lower installed height) rather than have the spring installed at a height greater than the manufacturer's specification (spring looser than intended by the manufacturer), as this will allow slop and loose operation of the spring outside of its harmonic range which could cause valve float.
 
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