I am looking for ideas and suggestions on Vortec head springs. These heads will be on a 383 stroker, with factory hydraulic rollers. The cam will be above stock, but below .480 lift. Will be used with CCC carb and stock computer with ZZ4 chip. I want something to last a while, and I do not want to modify these heads for higher lift. I simply want to swap in better springs.

joeEZ@bellsouth.net

 

Joe,

Welcome Aboard!

Even though you mentioned that the cam will not provide over 0.480" gross lift, the ramp of the lobe may be a factor. Do you have cam specs?

 

Not to stir the pot too much, but fitting your Vortecs for the larger 1.500" springs won't cost very much at all to have your local machine shop do it. Comp Cams sells a tool that will reduce the guide, and open up the pockets, but like I said, without looking at the receipt I think labor was $50, and all parts were less than ~$150(springs, locks, retainers, seals). In all likelyhood, you probably won't need to upgrade, like Vader said the ramp rate is going to be the determining factor. Roller cams are generally more aggressive than flat cams, but a hydro lifter is lazy reacting which artifically reduces the ramp rate.

 

I'm in the middle of making the same decision.

The cam I'm using has .442"/.465" lift with 214/224 duration. The best springs I've found are Comp Cams 981-16.

They're good up to .490" lift. That may be coming close for your cam. Since most springs are rated at .060" clearance before coil bind, and the springs aren't always 100% exact, you're getting close enough that you should physically check them yourself.

The nice thing about those springs is the ID. The Vortec heads have VERY large valve guides down near the spring pocket. Mine measure .860" , and the 981-16 springs are .880" ID with damper, so they should fit great without machining.

The compression rate @1" is pretty high for being single springs, which is good for cams with steep lobes (like Vader pointed out). The rate is 423 lbs/In. according to Comp Cams chart

http://www.compcams.com/catalog/302.html
Just look at the 981 on the far left column. That's the springs.

Of course the BEST thing you can do is call the company that ground your cam; not listen to a couple wahoos on a messageboard.

 

Thanks to all for your replies. The cam specs are .433/.462 lift, duration @.050 is 197/210 Gross duration is 289/308 112 Lobe center. This is going in a 383 stroker with 9.6 CR, hypereutectic pistons. CCC Q-jet carbed with stock computer and a ZZ4 chip to delete EGR. The heads are stock Vortecs that have been milled .010. Thanks. joey

 

That's basically a stock cam. I think you'll be a bit underwhelmed.

But in any case, any of the major cam mfrs' entry-level 1.25" dia spring, along with the retainers and keepers that go with them would be fine; Comp (part # 981), Lunati, Crane, Ultradyne, etc. I'd avoid GM springs of any kind, and springs from anybody that doesn't also make cams; this would include K-Motion, Summit brand, and other "budget" ones.

 

i've been checking into this myself for another project and as i recall the springs for the LT4 hotcam kit are a simple replacement and will handle the extra lift. haven't tried it yet to confirm, but plan to.

 

The HOT cam springs fit right on the Vortec heads? I was thinking the heads needed machining for them?

I'm looking into this myself for my S-10 project.

 

From the research I've done, the ones I've found are the only ones that will clear the valve guide and seal because of the .880" ID.

I was considering going with the H-11 springs from Crane, but they'd require the valve guides to be machined to a smaller diameter.

I just bought some used Vortecs for ~$225. I dropped them off at the machine shop yesterday. It's gonna cost me $125 for a 3 angle valve job and $56 to shave .007" because they're slightly warped.

After the springs ($60) I will have spent ~$470. Not bad for a set of heads built for my engine (mild 350). Heck, if it only costs ~$100 more to have the valve guides cut down and the spring pockets enlarged for bigger springs, I may step up to a roller cam, but I'll have to see first.