fiveoformula

What could be some possible causes of this? Ive only been running these LS6 springs and comp cams retainers for less than 1500 miles. the keepers are the stock style 7 degree.
Cam is a Lunati, lift is .507" in .515" ex

fiveoformula

This is a pic from when I was installing them last month.
Anyone think a lack of locators on the bottom of the springs could be the problem?

RamIt

Man. I was hoping we wouldn't hear back from you about the spring problems you were having. Bummer.

Are those 787 retainers? If they are they probably should be matched with the 648 locks. 787/648 combination will increase your installed height ~.030 and drop spring pressure.

With the new locks you could drop in spring locators and end up with the same spring pressure as before.

Here is a pic of the above mentioned retainers and locks.


Here is a picture of some Manley locators that are .035


As I mentioned before you should really talk to a machinist before you buy any more parts. They usually have seen it all throughout their career.

redneckjoe

i wonder, if those are self-aligning rockers,...is the washers on the side of the self aligning axle could be touching the retainer?

fiveoformula

Thanks for your input, really wish I saw your advice before I put it all back together. The part number for my retainers is comp cams 774, they say that they except the 7* keepers on the summit website. Whats the difference between the 774's and 787's I wonder?

paulo57509

http://www.compcams.com/Products/CC-...ries%27-0.aspx

fiveoformula

Wow, could that be my whole problem? It says my 774s are for a gen III LS engine and the 787s are for non-gen III. Do LS and SBC use the same size 11/32 " valve stem?

-edit, answered my own question, LS uses a smaller 8mm or (close to 5/16") valve stem.
I guess I need the 787 retainers
7* keepers (The ones I have should be 7*)
spring locators

RamIt

I don't know if you need locators. I prefer to use something to locate the base of the spring. Either the guide or locators. I would ask someone that deals with machining heads that could provide their expertise.

Yes the ls engines use 8mm stems so looks like you found one potential problem.

Good luck and post back on your outcome after a few thousand miles. It will help others in the future that use the search function.

fiveoformula

I will let you know how it goes. I think I need to find a new machine shop to go to, the guy at the local one is a nice guy. And he supposedly builds lots of high performance SBCs but I dont think he builds any for street use. He did install the last springs/retainers (he sold me the springs) and this is what they looked like when I pulled them out...

RamIt

If he installed that setup I would be asking him to correct it. There is no reason for sloppiness like that.

fiveoformula

I'd like to but I won't be pulling the heads, and its not like he will come to my garage and work on it in the car. He will hear about it though..

What's the best way to check for coil bind? I know its not likely with the beehives, but I want to check everything.

MoJoe

iTrader: (5)

To measure coil spring bind:
1) remove spring.
2) Reinstall retainer and keepers, measure the "installed height" for the spring. (1.800" +/-)
3) If you don't know cam lift, measure via a lifter. This should be in .280" - 0.320" range. Multiple by rocker ratio (1.5? 1.52? 1.6?) to get valve lift. This will be in 0.428"-0.530" range depending on your cam.
4) On a spring tester, compress the spring to installed height (1.800"-ish), compress it more using the valve lift number (down to 1.372"-1.270").
5) Finally, compress it down to coil bind. What is this height?
6) The difference between the height in #4 and #5 is your minimum clearance. It should be at least 0.060" to prevent coil bind while the engine is running.

fiveoformula

Thanks MoJoe, Ill see how it turns out.

I think I figured out why I ordered the 774-16 retainers, this car craft article has the wrong part number
http://www.carcraft.com/techarticles...pring_upgrade/

Just goes to show you, need to double check everything.

paulo57509

Use the component manufacturer's web site and tech lines.

And NEVER trust a magazine article.

RamIt

And never trust what gets packaged into a box without measuring. I have had problems with comp shipping wrong parts with the right packaging twice.

fiveoformula

On the left is the correct 787 retainer for non gen III.
Didn't occur to me at the time that the ones on the right fit a little funny.

fiveoformula

Little update for anyone wondering, I have a few thousand trouble free miles on the LS6 springs now. Engine even got quieter once I installed the correct retainers, imagine that! lol
The machine shop I used probably wont be used again. My work uses them, and I have seen some of their other mistakes. They will be my last resort next time.
Plans have changed a bit for the car, I aquired an all alluminum 5.3 that I will be swapping in, This 350 might live on in a new chassis though, possibly an S10 pickup, But for now the 350 is running great, doing burnouts, having fun. lol