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Ok, what is the maximum lift you can use safely with the Vortecs? I have heard of some using cams with as much as .490 lift with the stock springs. I dont want to change springs, period. Does any one have a larger cam with their Vortecs? If so, what size???
Do you guys think this cam would work?
This cam would be going into a stock 1997 Chevy Pickup with headers and an Edelbrock base. Do you think a guy would have to burn a new prom for this cam also?
There are other issues besides the valve springs. The valve guides are tall, so the retainers hit the top of the valve guides.
So, yes, that cam will probably work. It's not impossible that on your particular heads, maybe even both of them, that you could even use a little more than that. But it wouldn't be much more, because then you will get into the spring-limited range.
I think it would probably be OK with the stock chip butwould run a whole lot better with one specifically tailored for the motor and the owner's preferences, as always.
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"So many Mustangs, so little time..." ICON Motorsports
I wouldn't even think about stock springs at that lift - I went .470/.480 and upgraded to the gmpp 1.25" springs. There are a few people on this board running .480 on stock vortec springs - I'd like to test those springs after a year of use. I had a set of vortec heads set aside for my tpi car but ended selling them (partially because the intake base will probably never come out) and with the aggressive roller profiles couldn't find a lift under .500" that I wanted which entailed - at least to me - screw in studs, retainer clearance issues and larger diameter springs - which is getting close to TF heads in price. FWIW, the stock springs are rated at .460" if I'm correct.
Why not just upgrade the heads to accept more lift? It cost me about $150 for springs/retainers/valve seals, and having the valve guides/spring pockets machined. The Weiler Vortec heads I got came already done up-----Stainless valves, upgraded valvesprings, machined for guideplates/screw in rocker studs, accept lift up to .550"
On a 97 Pickup there is no PROM, the ECM will have to be reflashed for optimum performance...you should try it first and see how it runs before looking at reprogramming. The factory ECM's will surprise you at how much it can keep up with camshafts, LS1 ECMs can take 475hp with stock programming, more if they have the 2001 Vette Z06 calibration.
As for camshafts a good one for .450 lift would be the 1996 LT4 production camshaft, using 1.5 rocker arms, it hits right on the borderline of maximum lift for stock Vortec heads.
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-Joseph
ASE Master Automobile Technician
Scoggin-Dickey Chevrolet
1967 Camaro (Vortec Heads, GM ZZ4 intake manifold, ZZ4 roller camshaft) 1992 Firebird (Weiler Vortec Heads, LT4 Hot Cam, GM ZZ4 Intake, Edelbrock 750, eventually will be Ram-Jet)
The springs were around 35.00 from scoggin-dickey - very good deal.
Joseph - don't you guys offer a modified set of vortec's ? I had good luck with my first set on a carbed car (they were not stock however) and would consider the upgraded set if the tpi intake issue was resolved - what is the release on the base now ?
Yes stock rocker arm ratio is 1.5 on a SBC except LT4 which was 1.6 rollers.
I don't work for the parts department, but I buy enough from work to know a little
I don't think we get out upgraded heads from the same source anymore, mine first ones were done by Weiler Performance. They don't use them anymore because they were using off-brand engine bearings in some of their engines they sold us, when they were supposed to be King bearings.
But...I know there was 2 upgrades available for Vortec heads, not sure on price anymore.
The intake base is being cast for us by another company, will remain unnamed by me, byt there was a problem in some castings with porosity, and that is why there is a delay. We have a prototype intake already bolted to a engine, should be installed sometime in the next month. I dunno when the intake will be released...I think the ppl casting it put it on the back burner while they are doing their own casting on their products first, who knows.
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-Joseph
ASE Master Automobile Technician
Scoggin-Dickey Chevrolet
1967 Camaro (Vortec Heads, GM ZZ4 intake manifold, ZZ4 roller camshaft) 1992 Firebird (Weiler Vortec Heads, LT4 Hot Cam, GM ZZ4 Intake, Edelbrock 750, eventually will be Ram-Jet)
I've been running .462/.469 lift on my stock vortecs for like a year now or so I guess. No problems. The cam is a CompCams XtremeEnergy 262 BTW (218/224 @.050). I don't really know anyone specifically running a HR cam w/ the Vortecs yet. Quite a few people have been running the next cam up from mine, the 268 w/ .477/.480 lift I believe it is w/ no problems. Haven't heard of a problem yet w/ anyone except one guy who "upgraded" the springs w/ fairly cheap K-motion springs and had nothing but problems... He swapped back to the stockers and last I heard hadn't had any more problems.
Last I saw Scoggin Dickey had hi perf Vortecs for around $550 a pair that supported .550" lift though, that looks like a good deal to me...
