MotorHead17

I am putting a cc503 in my 1994 z28 and have read about lots of people liking these valve springs so I went ahead and bought a set. Everywhere I read it said they would come with shims, but I did not get any shims. So, what all do I need to run these springs? Do I just need shims, or do I need new valve spring seats also? Please help, would really like to get this engine together very soon here.

Kevin97ss

It should have come with shims for use as the spring seat, since it did not, contact the seller.

Ideally, ID spring locators would be what you want to use but present complications with install height and spring pressures.

Catmaigne

iTrader: (6)

The shims that are included are paper thin. I would stick with them though on a cc503 because more pressure is excess and puts more wear on your valvetrain.

Kevin Blown 95 TA

They used to come with some thin blue spring steel shims (.010?) that replace the spring seats but didn't really fit well around the guides. In your case, you should check the installed height and order the shims you need. There should be something between the springs and the heads, and you should set up the height anyway. Also take a look at your rocker arm to retainer clearance with those, make sure nothing is touching. Back when I had a set of those and SA crane golds, I had some contact underneath on a couple of them, and so did some other guys - that was with stock heads with 3/8 studs which I had machined flat on top.

MotorHead17

So I should check the install height. And then order shims to get my installed height to 1.850-1.875. And the shim will be the only thing between the head and spring? I understand that you don't want the spring directly on the aluminum head, but it just seems like there would be a more precise way of locating the spring on the head.

Kevin97ss

There are two ways to locate the spring on the head, cups, does what it sounds like. It cups the outside of the spring. The other way is called a spring locator and it sits up the middle of the inner spring. For small dual springs with 11/32 stems and resulting chubby valve stem seal, the locator keeps the spring from dancing around and contacting the valve stem seal. The problem lies with the thickness of the locators which range from .020-.060in. .050in is very common which would put the install height ~ 1.800. That's a lot of spring pressure when they are new. A .020 thick locator would be better but the last time I was shopping for them, the part that had the correct dimensions (ID, OD) was only available .050 thick. So I got the +.050 locks, spring height looked good, valve stem tip did not. The self aligning rockers would not work because there is not enough tip height. If you have NSA rockers they should work...depends on the valve job.

MotorHead17

Ive got scorpion SA rockers. I'm just confused why the crane instructions say that the shim replaces the locators.

Catmaigne

iTrader: (6)

Locators aren't 100% necessary. I ran the 10308-1 kit with only the shims and had no issues with inner springs contacting stem seals. I think locators are a good idea with higher spring pressures and SR cams, but a 503 and some Cranes isn't a radical setup. Get a micrometer and measure the installed height. I wouldn't go under 1.850".

Kevin97ss

The shims take the place of the stock locators. Stock locators will not work with this kit. The shims in the kit will keep your install much simpler and they are fine to use. Call Crane and ask for the shim package that should have been there...if they wont give it to you be sure to ask them the dimensions so you can buy the right stuff.

BALLSS

The crane kit, I believe, comes with a hardened steel what I will call spring shim but unlike a shim it is hardened metal. Shims themselves are often a softer metal and are intended to add space to raise this initial spring base shim aka "locator". On AL heads you need this hardened steel "shim" (looks like a washer) between spring and softer metal AL head

A "spring cup" would be the same but have a raised outer lip to better contain the spring. A spring "locator" would have a inner sleeve raised that fits over the valve guide base

MotorHead17

Well, I called Crane today and they discontinued the shims. They were .015 so does anybody know anyone who makes .015 hardened steel shims?

MotorHead17

http://www.summitracing.com/parts/cca-4739-1/overview/ Would these work?

BALLSS

I don't recall the OD of the valve stem guide but if .645 fits over it that yes those will work. You need 16 of them

MotorHead17

9/16, I'm pretty sure at least.

BALLSS

you should have hardened spring seats on your heads now. If they accommodate the same size OD as the 10308 springs you can just use the ones you have now

MotorHead17

The factory seats won't work with the Crane springs. The locator on them won't fit inside the Crane spring.