I was thinking... Does anybody make valve spring retainers with different heights? Doesn't seem like it would be too hard. Just change the way the cup is cut for the valve lock so that it pushes the valve height down just like the exhaust rotator, but without all the weight? Would make retrofitting 76+ heads much easier than shimming. Just gotta make sure you're not a dork and you don't switch up the retainers.

 

There are retainers that will allow a increase in installed height
like +.050". and there are keepers that will do the same thing.
They cost more.......
There are no retainers that will reduce the installed height
to correct the differnce when you replace the rotators with
standard retainers, that I know of. I looked into this my-self.
If there were, you can be sure they would cost a lot more than
standard retainers.
Spring shims are cheap like .20/ .30 cents each
You need 8 .060"+8 .030" +8 .015" to correct this.
Pretty simple Eh!!! about $10

Most good machine shops got 'em kicking around on the floor.

 

I've never seen retainers for that purpose. However, I have seen one-piece (0.300") cups designed to replace the rotator, but on the bottom end of the spring. Personally, I would want to have as little reciprocating mass as possible hanging on the tops of the valves.

 

Well, what I was thinking of basically moved the flat of the retainer down without adding much mass, if any. Basically a way of making the point where the valve lock comes into full contact with the retainer however much higher it needs to be in relation to the point where the spring contacts the retainer to cause the spring height to be shorter.

Do those cups work for a 1.25" spring? I have stock size springs from Comp that came with my K12-242-2 XE268 K-kit.

 

The only spring seat cups are for the Big Block chev motor.
Much bigger spring dia.

 

Lunati #86603?

http://www.lunaticams.com/PushrodsRockers/86603.html

 

just get 8 retainers of the same configuration as your intake valve spring retainers and use those on the exhausts with the same height springs as your using on the intakes.

Set the springs at 1.720 or the recomended height of the cam co. If the spring seats are dialed in and the valve job was done with any skill at all, the stem heights will be real close to the same and
will need a minimum of shims.

Bottom spring cups are a crutch and are sometimes frowned upon, as the bottom of the valve spring needs to move around just a bit. In fact the spring moves around so much that a single hardened .015" shim is used by astute cylinder head assemblers at this position (especially on alloy heads) to eliminate the holesawing effect on the spotfacing of the head.

 

from the info on the site it says they are .300" thick
That would reduce the installed height way too much.

The installed height on a 305 heads exhaust side when using a stock retainer is right around 1.84"

These spaces also cost $35. I don't think they are for small block chevs.

Spring shims are the only economical way to correct this.

They are availiable from Crane, Comp, Speed Pro, etc.
I paid $32 cents a piece for the last ones I bought.
Thats like $7.68/ pair of heads. (can)

 

http://www.competitioncams.com/catalog/319.html

IMHO these are not a "crutch", they allow you to more accurately control spring location. They allow you to use a smaller spring in heads cut out for larger ones. They protect the head from the "holesaw" effect as mentioned, which is a definite plus on aluminum heads especially. There's no reason for the bottom of the spring to move around, any more than the top needs to. In fact they will last longer and perform better if they're held still, except for being allowed to rotate if they want to (which they should).

The problem everybody's talking about here is the way taht the exhaust spring pockets are cut about .100" deeper than the intakes, to make up for the extra thickness of the rotators. On most of those heads, there's enough material on the intake side to cut it to the same depth, at least with stock diameter springs; of course, anybody that's serious about their heads wouldn't be using stock diameter springs anyway, but that's another matter.

The thin hardened washers are almost a "must" in a high-perf situation where longevity is expected and cups are not used... I've taken apart heads where the spring (the damper, mostly) has literally cut all the way through a regular shim.

 

I've done a bunch of stock heads with the rotator/retainers, deeper spring pockets, making them work for more performance, etc, etc.

All I can say is............ what RB said, above. Dead-on.

 

I used to live here until it caught up to me....