I have the 26918 beehive CC springs to put on my stock LT1 heads ('94). The cam I'm using has a lift of .577. I'm going to use CC Pro Mag RR's 1.6.

When I pull the original springs I believe there will be a shim under it, Should I leave the shim there for the 918 springs or will I need to add aditional shims?

The CC tech guys says a machine shop has to measure it for proper distance. Sounds to me he's just covering his back side in case something goes wrong.

So what should I do? Shims or not to shims?

 

I would measure and shim it. Valve spring height micrometers are relatively inexpensive.

Mike

 

I've always been told you should always check the installed height, and shim as needed to get it equal for all the springs. If you happen to get a PERFECT set of valvesprings, you won't need shims; that never happens. I've also been told that you can also shim the springs in order to increase pressure on the seat; at the same time, you lose maximum lift, due to coil bind. Hope this helps, others will probably have more to chime in.

Ian

 

Buy the height mic and some extra shims. Measure it yourself and shim to the recomended height. I measure each one.

Unless you know how to figure spring rates I would go with the manufaturers recomended installed height.

 

I don't think he's talking about install height here, although I would definitely recommend checking it during install.

If I understand you correctly, you are talking about the spring locator on the head. It looks like a shim, but is molded to hold the spring in place. Aluminum heads need locators to keep the spring from wearing the spring seat down. The 918 springs will fit into the stock locators, but not very smoothly. I would recommend purchasing the 918 locators from CC and replacing the stock ones.

I recently put 918 springs on my heads, and I reused the stock locators. The new spring did not seat as well as the stock spring did. At the time, I wished I had purchased the 918 locators; although I haven't had any issues since the install (~1000 miles)

Thomas.

 

So there is not a shim under stock spring, but rather a "locator".
Check out the link to CC website on spring install

http://www.compcams.com/Technical/Pr.../ValveSprings/

Is this procedure what I need to do?

 

Correct, there is no shim under the stock springs, but there is a locator under there. (I could see some people calling it a shim)

The CC article is the valve spring install procedure. The only difference is, the LT1 head doesn't have spring pockets, but rather a spring seat machined into the head. Then a locator slides over the valve stem and the springs sits on the locator.

Thomas.

 

What's the part # for springs locators to be able to use 918 springs on LT1 heads.

 

4705-16

 

http://web.camaross.com/classifieds/...ct=281&cat=all

 

That was very quick.Thanks.

Josh'95Z28conv,

I am ordering new springs with 787-16 springs retainers and locators from Summit. Is 795-16 the 10 deg retainers.

Anyone know if there are titanium retainers for 918-16 springs that fits LT1 heads. I found 772-16 tit retainers but they are for LS1 engines.

 

Shoot us a PM if you'd like we can get you a better deal on the springs,retainers,locks, etc than summit's price. :-D

 

So can I use the stock locator with the 918 springs??? I have 787 retainers.

 

Check post#5, above, I think it has the answer for that. I am going to get the springs locators 4705-16.

 

He's not kidding, I bought almost my entire valvetrain from him, along with some other goodies