JDMZ28

iTrader: (1)

Do any companies sell aftermarket springs for the vortec heads without having to get the heads machined? They will need to be able to accept at least .523" of lift.

When going from center bolt valve cover heads to the vortec heads do pushrod lengths need to be changed?

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1986 CAMARO Z28 -> 151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, T5 with 3.35 1st gear, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframes connectors, polyurethane swaybar bushings/endlinks, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.22@ 106.4MPH Next mods-> Homemade ram air, B&M shifter, Extreme Energy 230/236 cam, Holley Street Dom intake.

RB83L69

The spring pockets are for 1.25" diameter springs, but the most anybody says that 1.25" springs are good for is .500", and even that is a stretch (compression?) Comp has some new ones that are conical that might work at that lift, 1.25" at the bottom and 1.44" at the top, but you'd need the 1.44" retainers too.

Someone else experienced a problem with the retainers hitting the top of the valve guides, at considerably less lift than that. You might want to get some of those "check springs" and look at that, as destruction would be certain. Seems like you could have the top of the guides milled off if there was a problem. But if you have to do that, you might as well get the other machine work done too.

I don't know about the pushrods.

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"So many Mustangs, so little time..."

JDMZ28

iTrader: (1)

Comp 981's are good for over .500" lift and are a 1.25 OD.

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1986 CAMARO Z28 -> 151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, T5 with 3.35 1st gear, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframes connectors, polyurethane swaybar bushings/endlinks, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.22@ 106.4MPH Next mods-> Homemade ram air, B&M shifter, Extreme Energy 230/236 cam, Holley Street Dom intake.

vortecfcar

so u want the lt4 hot cam too huh?

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91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 280 grind. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, ****ty stock converter
13.24@104

FastBroker

Scoggin Dickey has some single GMPP springs without damper that will fit and are like $35 for the set, FYI...

RB83L69

There are 3 people in the last few weeks that have posted on this BBS about valve train problems that are clearly the result of inadequate valve springs. One with pulled studs, one with roller lifters wiped out, and one other I can't remember the details. All 3 had the only 1.25" springs on the whole planet that are spec'd for anything above .500" lift.... the GMPP ones. Go figure. I personally will not use that product. There is also one other mfr. that sometimes vaguely claims to have 1.25" springs that are good for up to .600" lift, but if you actually talk to them, they recommend stepping up to real springs at .500". I won't use that company's product either, not even if they were free. Comp specs 986s at .502" of lift if you look at the cam cards: they might say the 981s will do that in the springs' own specs, but they won't warranty the cam if you use them that way.

This is AFAIK GM's first entry into this market. They have never sold performance valve springs before at all, and all their racing progams have always used aftermarket ones.

I can't think of many worse places in a motor to try to take shortcuts than the valve springs. They seem like such a tempting budget target. But the price of doing it right is far less than what it costs to clean up the mess they can make afterwards.

Vortecfcar: what springs are you using with the 280? IIRC that cam has well in excess of .500" of lift... also, did you run into any problem with the retainers & guides?

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"So many Mustangs, so little time..."

[This message has been edited by RB83L69 (edited December 20, 2000).]

super chevy

I just bought a set of FastBurn heads and 1.6 roller rockers from Chevy. The FastBurns have the LT4 springs that are supposed to be good up to .525 lift. I'm running the Lingenfelter 219/219 .525/.525 cam right now in my 383 with TrickFlows and 1.5 rockers.
With the 1.6 rockers, the effective lift with the Lingenfelter will be .560/.560, as such, I contacted Trevor Johnson Cylinder Heads here in Dallas, and asked them about a spring upgrade to handle the cam. Here's their response:

If the springs on the fast-burn heads are 1.250 O.D., then the comp cams 941 spring would be the best choice.This spring has 130# of seat pressure at 1.750 installed height.We do not charge to simply install new valve springs,but you should check your installed height before ordering springs.The 941 spring is around $135 and our porting options range from $300 to $1500, depending on the power level you are trying to achieve.Please feel free to call us at 972 772 7979 from 9-5 Mon.-Fri. I would be happy to answer any questions you might have.

I'll be taking them my heads after the first of the year to get the springs and a little pocket porting.
SC

z/28cwby

If I'm not mistaken, the Vortec heads have pressed in rocker studs. Wouldn't pose a problem with high lift cams, and heavy valve springs?

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1984 Z/28
GoodWrench 350, Edlebrock Performer intake, MSD 6AL Super HEI kit, Crane CompuCam 2040, Edelbrock headers, Catco cat, Flowmaster aftercat, K&N, Custom 700R4, B&M Megashifter, Eibach springs, Energy Suspension Hyperflex kit, KYB GR-2 struts/shocks, Jegster adj LCA's, Lakewood adj panhard bar, BFG Comp T/A's, 180* stat, AutoMeter Pro-Comp COOLANT GUAGE.

super chevy

Yeah, the Vortecs use press-in studs. The FastBurns come with screw-in studs.
SC

vortecfcar

the cam Im using is a flat tappet hydrualic with 226/230 duration and .477/.480 lift, I have stock stamped rocker arms and STOCK vortec valve springs. this engine has seen over 6000rpm before without a problem and will probably happen again. Hot Rod did the same thing on theyre junkyard jewel. Forgive me if the 280 grind was incorrect, thats just what I remembered seeing for a 230 @ .050 cam. I hope this helps.

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91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 280 grind. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, ****ty stock converter
13.24@104

JJ

I have the same cam as vortecfcar, I am running the gmpp springs on my vortec heads. I think this is one area I am not having problems with. However, I have another set of vortec heads that are going to go on another car and I will probably have them machined for "better" springs to fit and have screw in rocker arms put in also. Based on normal roller cam lift and the fact that I have a set of crane gold 1.6'a in the garage, I'm sure I'll end up over .500 when I pick a cam, and I would feel better with proven springs over .500.

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87 IROC, 350/5 speed. gmpp 350, vortec heads w/some work, XE268, 1.5rr's, 650dp, rpm intake, MSD ing., ect.
89 formula, L98.

ERIC'86IROC

I am also using the same cam as vortecfcar with no problems. I felt comfortable doing this since HOT ROD did it then beat the engine on a dyno. STOCK Vortec heads, springs, and rocker arms.

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350 Vortec, forged flat-tops, CompCams XE268, Edlebrock RPM, Holley 3310, TH350 w/Holeshot 2400, 3.23 posi, Heddman shorties, HEI

Damon

But guys, .480 lift is a long way from .525! That's getting REALLY marginal for 1.25" springs with a 1.750" installed height. And if .525 is the actual lift you will be getting from your cam you DAMNED WELL BETTER BUILD IT TO TAKE .550!!! High RPM nightmares happen when you cut the safety margin too close. Give yourself and extra .025" or realize you are living on the edge.

On one motor I built that was limited to 1.25" springs I resorted to LONGER VLAVES! I went .100" longer than stock. THat then meant my installed spring height went from a stock speck of 1.750" to 1.850". That meant special springs (not really custom- just hard to find). This added height gave me retainer-to-guide clearance AND the taller springs would not bind until about .550 lift! Killed two birds with one stone.

Of course, I ran slightly longer pushrods to keep rocker geometry correct but it worked great.

Would I RECOMMEND doing it this way? Absolutley not. Machining for larger springs would be a much better way to go but if you are really really into 1.25" springs, it can be done.


[This message has been edited by Damon (edited December 21, 2000).]

JDMZ28

iTrader: (1)

What options do I have? Must I get the heads machined to run a competent spring?

I will be running: Comp Cams Extreme Energy 274. It is 230/236 duration with .519/.523 lift w/1.6 rockers.

What would be a good size to get the heads machined to to run optimum springs? What sizes can I choose from? How much is it going to cost? What would be the optimum spring for me? I want high quality but inexpensive. How much is it going to cost to get them machined for screw in studs?

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1986 CAMARO Z28 -> 151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, T5 with 3.35 1st gear, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframes connectors, polyurethane swaybar bushings/endlinks, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.22@ 106.4MPH Next mods-> Homemade ram air, B&M shifter, Extreme Energy 230/236 cam, Holley Street Dom intake.

[This message has been edited by JDMZ28 (edited December 21, 2000).]

RB83L69

First, check with Comp (and maybe others) to see if the conical springs will help. If not, you don't have alot of choice.

It's a pretty simple operation to machine the heads. They just take a mill and rout out the place in the head casting where the spring goes.

Somebody else on this BBS bought a set of those and put a cam with comparable lift (LT4 HOT cam?) in the motor; he broke several handfuls of parts before he realized that the retainers were bottoming into the valve guides. I would strongly recommend that you check this area carefully before assembly; if you have to get that machined, you might as well do the other too.

The apparent economy of those heads starts to fade rapidly if you have to spend that much money to make them work... it might be wiser to downgrade the cam to something that can coexist with them, and just realize that they have limits to what they'll do without spending as much as you would to get a set of Fast Burns and still not having Fast Burns.

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"So many Mustangs, so little time..."

JDMZ28

iTrader: (1)

I don't get it, why is it the springs for the LT4 HOT CAM will work for my heads but no others? What are the conical springs, how much are they?

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1986 CAMARO Z28 -> 151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, T5 with 3.35 1st gear, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframes connectors, polyurethane swaybar bushings/endlinks, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.22@ 106.4MPH Next mods-> Homemade ram air, B&M shifter, Extreme Energy 230/236 cam, Holley Street Dom intake.

RB83L69

The conical springs are Comp 982. They're somewhere around $60-65 a set. You'll need retainers too (about $60 more), because the top of the spring will not fit under the 1.25" retainer. The Comp retainers may be a bit shallower underneath than stock ones, which in turn might improve the clearance situation between the bottom center part of the retainer where it fits around the keepers, and the top of the guide where it protrudes from the top of the head.

I doubt the LT4 HOT cam springs will work in your combo, any more than any other 1.25" springs would.

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"So many Mustangs, so little time..."

JJ

that economy drops even faster if you have tpi due to the expected 400.00 price tag of the vortec/tpi intake . . . (sorry, that's another story)

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87 IROC, 350/5 speed. gmpp 350, vortec heads w/some work, XE268, 1.5rr's, 650dp, rpm intake, MSD ing., ect.
89 formula, L98.