c4boom

i have a set of competition products valve springs PN 2300 they have a 1.780 install hight and .600 max lift. at install hight they have 130 lbs of pressure and at .28 lift they have 250# and at 1.25 they are at 345#. they will go to about 1.064 befor it lookes like they start to have coil bind. what do you guys think of these springs would they be good to throw in when i do my valve springs and seals on my l98

Vader

I hope that was a typographical error. If they are coil-binding at 1.64", you're going to have problems.

c4boom

ya it was big time it should be 1.064 all fixed

Vader

At that installed height, you should have no bind problems. Teh spring rate also seems respectable - you ARE installing screwed rocker studs, right?

c4boom

wasnt planing on it. what are the speces on the stock springs

c4boom

bringing this one back from the dead still have the spring never got to put them in had to pull motor but was wondering if i should just go and sell them.

btw what are the specs for the stock springs

ede

stock springs, or gm springs in general belong in the trash or someplace other than your engine. you need to match the springs to your cam, it doesn't matter what heads you have. check the cam grinds recommendations

c4boom

i was thinking hot cam

joshwilson3

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DM91RS

I agree about the GM's. I'm looking for a set of Comp Cam's springs for the ZZ4 and the LT4 Hot cam's. I have not seen any spec's to find out what to order. Anyone have any specs for these cams?

OUTATIME GTA

iTrader: (2)

so pretty much any new aftermarket springs will be an improvement over the stock ones?

joshwilson3

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ede

about all i buy is lunati springs, but comp and crane both make good stuff too.

Vader

Stock SBC springs are rated at 85# closed seat pressure at 1.710" installed height. After a little bit of use, most of them won't even test that high. What's perhaps worse is the variation in "stock" springs. Coil bind height can be anywhere from 1.080" to 1.120" (or possibly higher). I'd suspect the spring pressures and rates vary accordingly, so they aren't very consistent across the years. You'll be far better off with something that has a more adequate seat pressure and predictable spring rate.

Even the GMPP LT3 "Hot cam" valve sprigns are a step up, since they have a bit more diameter and pressure (105# closed), and likely better quality control. If you're really looking for a budget spring, you can get a set for about $35, and they'll at least not bind up to 0.525" working lifts. That's not to say that they are the best spring for the job, but they are a step better than the standard SBC springs and certainly aren't what I would call pricey.

For only a few dollars more, you can get decent springs, but almost any spring that is really suitable is going to have a larger diameter and require a bit of head machining. I've never used a set of Howards springs, but they may have some promise, and offer 1.25" springs with good pressure and rate. Other Howards products seem to be good quality, but one never knows.

joshwilson3

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joshwilson3

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ede

lunati 73084 looks liek a close match. buy the reatiners to go with them and trash the factory stuff. if you don't like lunati buy comp or crane. you're trying to save a few dollars in places you shouldn't, buy from known quality sources.

Vader

If you don't want to machine your heads, check the 98215 at http://www.competitionproducts.com/page25.html. They're not as cheap, but they're not as cheap, either.

RB83L69

The right valve springs = pennies

The wrong valve springs = cubic mega $$$$ when a valve drops and goes through a piston; or they coil-bind and wipe a cam and shed metal in the oil and cause bearing destruction; or they pull studs and get coolant in the oil and ruin bearings that way; or any number of other stoooopid preventable things happen

The spring specs you quoted have (as usual) a whole bunch of little white lies in them. They say they'll go to .600"; but the installed height is given as 1.780", whereas stock installed height is 1.750". Shave .030" off of that glorious spec immediately. Then they give the pressure of 345 lbs at 1.25" height, which is .530" of lift from the installed height spec, and is about all you want to run on stock-type hydraulic lifters; and even at their reality-adjusted .570" max lift spec, they'll have almost 400 lbs of pressure.... way too much for a 1.25" spring or a stock cam.

Bottom line: they look like OK entry-level 1.25" springs, fine for use with a stock cam, but highly questionable at best for anything over .500" of lift .... as usual for a 1.25" spring.

As long as you don't upgrade the cam, and you replace the retainers and keepers along with the springs (they won't work with the stock ones), and you put about .100" of shim under the exhausts to make up for the factory rotator crap (use a .060", a .030", and a .015"), you'll be OK. Wouldn't hurt to check th einstalled height before you select shims. You might even find that you'll need less shim under the exhaust and .050" offset keepers on all of them, if the intakes have less than 1.75" installed height.

joshwilson3

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RB83L69

IMO the ones you posted first would be fine, if properly installed.

Just don't expect to use them at anything near their "specs", because those "specs" are a joke. But, they'll do just fine with a stock cam, or a relatively mild other one (less than .500" lift, moderate ramps, etc.).

The other springs you show aren't very much different from the Comp Prod ones. They're within a couple of percent of the same spring rate, very similar specs at similar heights. I wouldn't go buy those instead of the ones you have.

DM91RS

While the spring subject is still open....Will these springs work properly for the ZZ4 cam that has 474/510 lift and 208/221 dur at .050

CCA-986-16Specifications:
* Outside diameter: 1.430 in.
* Inside diameter: .697 in.
* Seat load: 120 lbs. at 1.750 in.
* Open load: 280 lbs. at 1.250 in.
* Coil bind: 1.150 in.
* Rate: 296 lbs.

I want the engine to be able to endure staying at upper rpms (3500 to 5500) for 30 minute periods with no problems. At least from the valve train. This is going on a Vortec headed 355.

Also might use 1.6 roller rockers ...unless that much lift is past the best flow on those heads with a light bowl blending or whatever else is recommended.


Thanks for any replys.

DM

RB83L69

Yes. They are one of the best possible choices for that application.

DM91RS

Thanks RB

DM

joshwilson3

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joshwilson3

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