Dr.E

Hi all!
I'm looking for some education on valve springs for my Gen 1 383 SBC with 441 iron heads. They currently have Z-28 springs and I have replaced the flat tappet cam to a retro-hydraulic roller cam with duration @ 0.050" 213 I 219 E .469 I .478 E 112 LSA (1.52 rocker ratio). This is a truck engine so I advanced the cam 4 deg. the original specs for this Lingenfelter L-98 cam recommended dual valve springs comp cams pn 977-16(155 seat load 420 open load). I believe these were designed for the corvette aluminum heads used in the TPI engines mid 80's until the LT-1 1992. I do have the FIRST TPI intake and don't expect to rev past 5000 rpm.
Educate me on my options please.

AlkyIROC

Install valve springs with specs recommended for the cam grind. They don't have to be a brand specific but should be close to the recommended specifications. Buy a Comp Cams camshaft and they give you a Comp Cams recommended valve springs but you can use any brand you want. Same goes with every other cam manufacturer.

Valve springs do lose their spring tension eventually. Old stock springs should be thrown out unless you have a spring tester to see if they still provide enough pressure at a specific compressed height.

There's a lot of measurements to setting up valve springs properly. Not all the spring pockets are the same size so installing heavier springs for a cam swap may not be the same diameter as what the heads were originally designed for. Beehive springs get around this by having a smaller base to fit into a smaller spring pocket and have a larger top which allows for a higher spring rate without having the spring pockets cut for larger springs. Not quite as good as proper larger springs but they do the job.

Installed height is how much room is between the underside of the spring retainer and the bottom of the spring pocket. If the installed height is too much, the springs can be shimmed to decrease the height. If install height isn't enough, the simplest way to increase height is with different keepers which will move the retainer higher on the valve stem.

Slapping a set of springs into a head without checking tolerances is just asking for trouble. Do it right the first time.

Dr.E

Thanks AlkyIROC!
So to sum it up;select springs with the recommended specs by the cam manufacturer?
I was thinking that newer spring tech would offer additional options, considering that this cam and spring combo came out before beehive springs. Is it true that I can run lower seat pressure with beehive springs? Maybe 125-130 seat and 300-350# over the nose, instead of the dual spring specs of 155# seat and 450# open load?

AlkyIROC

That would be a little too weak for my liking.

skinny z

Yes. Comps 26915 (for standard length valves and installed heights less than 1.8") and Comps 26918 (for longer than stock valves and installed heights greater than 1.8") will handle that cam.
For what it's worth, I've run the 26918 with cams similar to your spec as well as on cams with significantly more duration and lift with a 7000 RPM redline. No troubles.

Dr.E

Thanks for the info!
I have seen some folks using Gm take out LS springs, but I have also heard some say that GM springs are poor quality? If this is a viable option? If so, which GM part# will be an option in my application? Yes I have stock valve lengths and my guides have been machined for umbrella seals with the Z-28 springs currently installed since the original flat tappet hydraulic cam had very similar lift #'s

skinny z

I can't comment on the GM springs as I've always used the Comp 26918 in my RHS heads or the previously run Vortecs. There are others here that have an opinion on the LS springs. Perhaps one of them will chime in with a recommendation.
If you have the traditional valve stem seals, then the small diameter conical spring will fit over them. You'll need a spring locator that positions the spring via the inside diameter.

Dr.E

Thanks Skinny z !
That is the kind of heads up detail I need. I was also unsure when and if locators should be used since the Z-28 springs are 1.250 OD I was looking for the details like locators, shims retainer/locks and part#s if available.
Thanks again!

skinny z

To outfit my heads, with a 1.550" valve spring pocket:

Competition Cams 26918-16 Beehive Valve Spring

Competition Cams 4705-16 Valve Spring I.D. Locators for 26918-16 Springs

Competition Cams 774-16 Steel Retainers for GM Gen III, 7 degree Angle for 26915 and 26918 Beehive Springs

Competition Cams 648-16 Machined Steel Race Locks, 7 degree Lock Angle for 11/32" Valve Stem Diameter

The valve stem seals have to be removed to install the locators. Shims might also be needed to achieve the desired installed height.