Z28 Elgin springs
 

Hi,

This seller says that they are made for + 0.100", but says they only can take 0.550" in total
I have a cam with 0.565 and 0.570 lift, will that be ok?
It's a roller cam.

Thx.

From the seller.

This listing is for a brand new set of Z28 +100 style performance valve springs, hardened spring retainers and hardened valve locks that are made by Elgin Industries. Set includes 16 springs, 16 hardened spring retainers and 32 hardened valve locks.The Z28 +.100" springs are stock outside diameter and can be used in many 1955-1993 small block Chevy V8 cast iron cylinder heads. They work great for stock, towing and most mild performance cams and work best with cams up to 0.550" lift. Many sellers claim these springs can handle up to 0.600" maximum lift but I personally don't believe they have enough spring pressure to handle more than 0.550" lift.

Valve Spring Specifications:

• Spring Part Number: RV1943X
• Outside Diameter: 1.260"
• Inside Diameter: 0.785"
• Closed: 125 lbs. @ 1.750"
• Open: 325 lbs. @ 1.200"
• Coil Bind @: 1.160"
• Spring Type: Single with damper

you have a lift of .570 and the manufacturer says .550 is the limit, so I would say you cannt use them.

The seller is saying he think it can take 0.550
So my questions is, can it take 0.570?

The next cam is 0.560/0.555

So I just put in a mild Howards roller cam that goes to 0.495 lift, and they recommended around 350 lbs open pressure. Those seem a bit light if you install them at 1.750.
I would double check what install height you will have with your valves to make sure.

First off roller cams should have seat pressures of around 140 pounds closed. this is listed at 125 # at an installed height of 1.750 inches. second problem is the coil bind at 1.160. The lift at coil bind is 1.750 minus 1.160 and you get .590 inches of possible lift. You really want to be around .100 or more above coil bind for float. surge, and spring longevity. 1.160 + .100 = 1.260 1.750 - 1.260 = .490 inches of max valve lift to be more optimal. they throw in an open pressure of 325# at 1.200 if you had a .550 inch valve lift. Personally I don't set up heads that close to coil bind.

typical springs are cheap. What is the diameter of your heads valve spring pockets? aftermarket heads for roller springs are generally 1.46 inches or greater.

Go to page 18. http://www.compcams.com/catalog/COMP...12_328-361.pdf

Spring number 985. 1.430 diameter, installed height 1.800 with 146# closed coil bind at 1.150 so your lift of .570 is good to go.
spring number 977 1.460 1.900 with 133# closed
Beehive 26925 and 26926 1.850

Thanks George,
The seat is 41mm = 1.61"
It looks like the 985 springe is the one to use, for this cam.

And yes, they are cheap, it's $120 or so.

Again, thanks for your help :thumbs:

Let me look at 1.56 inch diameter springs. running 1.430- 1.470 springs requires you to run a spring cup to keep the spring centered on the pocket. Your 1.61 can use the larger dia. Just to get things right. what size valves do you have? Just the head dia. Valve train weight determines the amount of pound springs to use.

CC 925 springs and retainers. Shimmed to
Slightly less than 1.850 to get about 140 seat

If your heads came with. 100 inche longer valve stems you can use the taller springs with 1.950 installed height. Then I would buy CC spring number 930 or 936

It is 2.05/1.6 valves.

:thumbs:

The valves are 0.100 longer.
The heads and valves can take 0.570 in lift.

Okay, here is your part list and you can order right from comp cams.

924-16 springs use 1.850 installed height
741 standard weight steel retainers or
1732 lite weight steel retainers
spring locator cups 4700

GREAT George, again thanks for your help :- )))

BR,
John