New Track Times
Thread Starter
Launching!
Joined: Feb 2010
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From: Capital region, NY
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.
TECH Fanatic
Joined: Jun 2007
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From: centerville, ohio
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 ?
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
Likes: 0
From: Capital region, NY
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 ?
"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.
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
Likes: 0
From: Capital region, NY
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
Likes: 0
From: Capital region, NY
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.
*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.
TECH Fanatic
Joined: Jun 2007
Posts: 1,255
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From: centerville, ohio
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.
Last edited by lt1-xjs; Sep 9, 2014 at 08:11 PM.
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
Likes: 0
From: Capital region, NY
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Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
Likes: 0
From: Capital region, NY
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.
Last edited by v8vette84; Sep 10, 2014 at 07:36 PM.
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
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From: Capital region, NY
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
Stock
My heads
Last edited by v8vette84; Sep 11, 2014 at 12:27 AM.
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
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From: Capital region, NY
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/
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/
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
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From: Capital region, NY
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!
TECH Fanatic
Joined: Jun 2007
Posts: 1,255
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From: centerville, ohio
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!
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
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From: Capital region, NY
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!
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Joined: Dec 2010
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From: Maricopa, AZ
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!
Last edited by hrcslam; Sep 11, 2014 at 11:11 AM.
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
Likes: 0
From: Capital region, NY
TECH Addict
Joined: Dec 2010
Posts: 2,610
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From: Maricopa, AZ
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"..
Last edited by hrcslam; Sep 11, 2014 at 06:12 PM.
TECH Fanatic
Joined: Jun 2007
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From: centerville, ohio
Thread Starter
Launching!
Joined: Feb 2010
Posts: 296
Likes: 0
From: Capital region, NY
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.