v8vette84

Well I got my shims today so I will be starting the process. Hopefully ALL I need to do is shim the springs......

v8vette84

I was told they were Comp Cams 987-16 dual springs. I was never able to confirm so I bought my own. I used Comp cams 787-16 retainers and I put the springs right on those factory locators. The springs I took off never had any spring cups either so I just didn't think about it. The recommended spring cups I saw were .060 thickness. So they would get rid of one of the .060 shims I need. Do I need spring cups? Comp recommends 4705-16 for the cups.

lt1-xjs

Yes you have to run a spring cup to locate the spring and to protect the head. I don't get the 1.9 with the 787 retainer. I put the same thing on mine with the stock locks and my install height was like 1.740" with no shims. With a 1.9 the 977-16 or the 26120 would also work. What did Lloyd say about having to shim over .100" ? What was wrong with the original 987 dual spring ?

v8vette84

"wow, that will definitely be a problem.

I would have the pressure tested and make sure they have not lost lots of pressure.

As long as you can still get 145-150 lbs on the seat they will be fine. "

His exact words. I was unsure if they were actually 987's. I did not want to run springs that had been run on another engine. Who knows if the springs were actually what the PO said they were... Thats my reasoning for not using them.

v8vette84

So the stock locators I posted pictures of are not able to be used? Don't the factory locators and the Comp cam recommended cups do the same thing?

v8vette84

Here is the additional info I got with the heads.

*CompCams 987-16 Double Valve springs w/ dampeners:
Installed Load: 121 lbs @ 1.800"
Open Load: 343lbs @ 1.200"
Coil Bind Height: 1.150"
Spring Rate: 370 lbs/in

*CCA-4770-16 Inner spring seats
*CCA-740-16 cromemoly retainers
*CCA-613-16 10 deg Valve locks
* stock-sized Replacement valves

I just did not want to trust a spring from someone I don't know. They were probably fine but I didn't want to chance it.

lt1-xjs

Yes you can use them, they do the same thing. I would check the install height on the seat, retainer and lock from the 987 spring.

v8vette84

Yeah... the retainer and locks and the 987 springs are 4 hours from me at my parents garage. Most likely lost as they were take off some time ago. Otherwise I would!

v8vette84

So i tried to start shimming today and the shims will not fit over the factory locators so I will need to buy the Comp ones as they have a squared hat instead of the rounded style of the OEM ones. The only thing I'm worried about is that what if the shims are taller than the hat that "locates" the shims? I tried to see what they do under the locator but they are like using an 1/2" washer on a 1/4" bolt. Just too big.

v8vette84

I also ran across a picture of another guy doing beehive springs and took a close look at the photo he posted of his LT and my heads definitely look like the spring perch was cut down. I mean here is the pic vs my picture. See for yourself. Its either that or the original machining was left rough looking...

Stock


My heads

v8vette84

Ok now I have a serious question to make sure I measured the spring height correctly. From what I saw online you don't factor in the recess on the top of the micrometer? All I did was use the reading on the side of the mic. The retainer sits in the pocket on the top of the mic. Is this a problem?
Here's how it sat to be measured in the micrometer. Do I need to factor out the recess?


I got that idea from this thread...
http://www.camaroz28.com/forums/lt1-...needed-623188/

v8vette84

If I factor out the recess I get a 1.750" installed height. Which would lead me to believe the problem lies elsewhere or my beehives have lost their pressure. I'm just not sure if I used the mic correctly or not now.... Even though the spring perch looks like it has been cut down... man this is getting confusing!

lt1-xjs

The 1.750" sounds right, set your tool at 1.800" and measure the width with some dial calipers. Most likely you have to factor out the recess.

v8vette84

I just called proform and you do need to factor out the recess. The recess is only there for the step on some dual valve spring retainers. So today I'll have to measure the exact depth so I can get my reading. If I am at the correct installed height why would I have valve float? Loss of pressure on the springs? Ok so that kinda sucks but it's also good! At least I don't have to shim to high hell! Thanks!

hrcslam

Maybe it's not float, or maybe you didn't get the right springs. Possibly a mix up? Maybe you can pressure (spring rate) test them?

v8vette84

I'm not sure, anythings possible.... There is a local shop that I'm going to try to have spring rate check them tomorrow.

v8vette84

Depth of recess=.140" out of the 1.9" I get an installed height of 1.760".

hrcslam

You could get something like this and check you installed pressures.....

Or since you already have 1 spring off, take it to the local machine shop and have them pressure test it. For the Comp 918's you need to compress the spring .376" to match your installed height of 1.760", it should read ~140lbs at that height. And about 355 over the nose or compressed 0.954"..

lt1-xjs

I would take a few and get them tested. Test them at 1.760" for seat pressure and 1.180" for open pressure.

v8vette84

So I had 2 different springs tested. I forgot to ask for him to test open pressure but Lloyd seemed like they were fine. At 1.760" I got 146lbs on one and 142lbs on the other. Lloyd told me that at 1.740" I should have around 150-155lbs on the seat which is fine. He told me to try preloading the lifters around 1/8" of a turn. Basically just keeping them quiet. Also to use the Comp cams locators I got as they will add a little more spring pressure then I'll report back.