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vortec heads

5K views 47 replies 8 participants last post by  Urbanfarmer 
#1 ·
Im going to get a set of new vortec heads from summit. I am going to use a hydraulic roller camshaft with .502/.51" of lift. Duration at .050" lift is 224 int/230 exh. What my question is here is what do I need for springs for that cam and lifters? The lifters will be stock GM roller lifters. Will I need to buy a new spring set and install them? The heads Im buying are the ones that summit already machined for up to .550" of lift so that wont me a problem. Does anything need to be machined for the use of dual springs?
 
#2 ·
awoodman said:
The heads Im buying are the ones that summit already machined for up to .550" of lift so that wont me a problem. Does anything need to be machined for the use of dual springs?

you just answered you own question. your all good if they are all ready machined. but i would recommend a set of rhs vortec heads. they are far better than a pair of modified stock vortec's. plus you can use any sbc intake you'd like and they won't crack like vortec's are known to do if you ever run them hot. :thumbup:

http://racingheadservice.com/Information/Technical/Heads/ChevyVortec-Heads.asp
 
#4 ·
According to what I see on the summit site, the heads are assembled with 1.250" outer springs with dampers and umbrella seals. If you want to know if the springs are compatible with the cam you're going to use, call summit and ask the (on the seat) and (open at 0.510") values for the springs they use. Then talk to the cam grinder and tell him the spring values and determine if they will work well with the cam's characteristics. You'll need more open pressure with rollers than you will with flat tappets, so talk to summit and the grinder to coordinate.

Personally, I'd use larger diameter springs with that much lift.
 
#9 ·
awoodman said:
Wow, is SDPC a well known place? That is very cheap. Do they do good machine work? And are the heads that you just posted already set up for a hydraulic roller cam?-are the springs meant for it? It just says hydraulic.

that price is per head. roller cam springs aren't very expensive $80 or so retainers $50 valve locks $8 but if they aren't roller cam springs i'm sure they won't charge $330 plus the cost of the new springs ect.. just give them a call
 
#11 ·
I have the summit vortec heads on my 350 and they work fantastic, the springs and retainers are made for hydraulic flat tappet cams, lost the papers for the grind I have on my cam I just know that its comp cams. I asked summit which one I should put in just make sure you have as much information about the car as possible when you contact them.
 
#14 ·
you need to use dual hydraulic roller springs roller cams have a lot faster ramp speeds meaning they open your valves a lot faster which puts more stress on your valve springs so you need more spring to compensate for that or you'll get valve float break springs and so on you need higher spring seat pressures bigger valve spings like insted of 1.260 od single springs go to something like 1.437 od dual hydraulic roller spring.
 
#15 ·
also if your block is not an oem roller block you'll have to get retrofit Roller lifters the ones with the tie bars to keep them from spinning out in your lifter bores and trashing your cam liters and valve train.Another thing that can help with valve float is use thiker wall pushrods like the .080 wall thickness.
 
#16 ·
no machining on sbc heads here's the new springs part number #26981 .525 max lift



Designed for stock diameter Small Block Chevrolet hydraulic, flat tappet or hydraulic roller cams with modest lift up to .525". This is a direct replacemenet for the old venerable 1.250" diameter 981 spring. It is designed to drop in a stock GM Small Block head with around 1.700" installed height and no machine work. The lower mass and higher frequency of the spring will outperform the standard 981.

http://www.compperformancegroupstor..._Code=CC&Product_Code=26981-16&Category_Code=
 
#17 ·
F-BIRD'88 said:
GM vortec head #NALvortecZZ5 from Summit racing comes with a 1.379" hi perf spring suitable for hi performance hyd roller cams. its is the valve spring speced for use with the GM "LT4 Hot cam"
it will work fine with your aftermarket .510" hyd roller cam.
You have to buy your own push rod guide plates for this cylinder head assembly.

GM vortec heads do not crack in normal use including normal high performance use.
This folklore came about from neglected abused stock heavy fleet truck vortec motors that developed a common intake manifold gasket leak, lost most or all the coolant and overheated as a result.
Any head will fail when abused like this.
Do not use the factory GM "vortec" intake gasket. use a felpro #1255.

Any aftermarket or factory vortec head that has been drilled for both the old and vortec intake bolt pattern still has a raised intake port location. You must use a vortec manifold or a reworked "raised port" manifold like the GM bowtie racing raised port manifold. A common '55 to '95 manifold will not work.
We build a lot circle track and street engines with the Vortec heads and have used the GM gaskets on all our engines we build with out any problems and the problems they had with the earlier gasket was from over torquing at the factory and the new gaskets have steel inserts in them now so if they are over torqued they will not split the gaskets on the ends.

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With out factual data your just another guy with an opinion!!!
 
#19 ·
The heads come pre-assembled with dual coil springs, 3/8 in studs also come but are in the box, these things are set and ready for your cam, lifters, pushrods and rockers as long as they are roller hydraulic although I'm pretty sure a flat tappet would work too you'd have to ask summit.
 
#20 ·
CNC BLOCKS N/E said:
We build a lot circle track and street engines with the Vortec heads and have used the GM gaskets on all our engines we build with out any problems and the problems they had with the earlier gasket was from over torquing at the factory and the new gaskets have steel inserts in them now so if they are over torqued they will not split the gaskets on the ends.

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I agree the GM gaskets are fine over torquing them can be easily done vortec intakes are only supposed to be torqued 11ftlbs.
 
#23 ·
Thanks for all the help. Im still kind of shopping around. I saw a good deal today. Online somewhere i saw that they wanted 800.00 for a pair of assembled sportsman II heads. Wouldnt I be much better off with these than vortecs? Im almost to the price of these with modded vortecs. What do you think?
 
#24 ·
awoodman said:
Thanks for all the help. Im still kind of shopping around. I saw a good deal today. Online somewhere i saw that they wanted 800.00 for a pair of assembled sportsman II heads. Wouldnt I be much better off with these than vortecs? Im almost to the price of these with modded vortecs. What do you think?

are you talking about these ? if so go for it, as long as they are brand new and from a reputable retailer, last thing you need is to dump more $$$ into them to have them rebuilt :thumbup:

http://theengineshop.com/prods_pages/011150.htm
 
#26 ·
It depends on the rest of the combo and what are the runner sizes of the heads. Going with a non vortec will be somewhat cheaper, being you wouldn`t have to buy a vortec intake. Sure some companies sell Vortecs with both mounting flanges the 12 bolt old style and the 8 bolt new style, but I would not bolt a old style intake on Vortec heads. RHS makes a nice vortec head, and the 170cc runner would fit a daily driver nicely, the price is right also.
 
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