Limits of Vortec Heads
Thread Starter
Pro
Joined: Sep 2004
Posts: 611
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From: Minnesota
Limits of Vortec Heads
I found that you need to mill the valve spring area on the vortec heads to except a higher lift cam. They only have a max. valve lift of 0.420.
If I use my stock L82 cam (.450/.460) will I have to do this mod to the vortec heads?
Is this something that an average person can do?
If I use my stock L82 cam (.450/.460) will I have to do this mod to the vortec heads?
Is this something that an average person can do?
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
Originally Posted by captainmorgan
Is this something that an average person can do?
Thread Starter
Pro
Joined: Sep 2004
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From: Minnesota
Originally Posted by 79VetteMike
There are varying opinions as to how much lift stock vortec heads can handle. I've never seen the figure to be only .420". I've read up to .480" in some publications and .450" in others.
http://www.sallee-chevrolet.com/Cyli...ds/Vortec.html
Le Mans Master
Joined: Mar 2004
Posts: 7,448
Likes: 1,476
From: Little Rock AR
I think the issue will be the top of the valve guide boss clearance with the bottom of the retainer at full lift. The usual tools I have seen are for cutting the valve spring pocket larger in diameter for larger springs. Not the same problem. There may be a specific tool out there for Vortec heads but I have not seen it.
-Mark.
-Mark.
Melting Slicks
Joined: Jan 2003
Posts: 2,804
Likes: 1
From: OKC Oklahoma
Originally Posted by captainmorgan
Pace shows them at .480". Very odd that these show such a range difference and they are the same head.
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Team Owner
Joined: Jul 2001
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
the performance potential with Vortec heads is very limited... I'd rather spend a little more on heads and have a much better power potential...
Vortec heads also require a special intake....
Vortec heads also require a special intake....
Melting Slicks
Joined: Jan 2004
Posts: 2,672
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From: New Cumberland PA
The vortec heads are about the best bang for the buck when on a limited budget. They not only out perform other iron heads but many alum heads as well until you get into the larger cc alum heads. The stock Vortec head should handle a cam with up to .480 lift. I believe the sallee spec is a misprint. There is a simple upgrade to increase the max valve lift and that is to switch the springs to Cranes's 10309-1. With these springs you can go to a cam with .550 lift.
The Vortecs are nothing short of phenomenal. But they do have several short comings. The lift is one, but is easy overcome. The others are the fact that a vortec style intake is needed, self-aligning rockers arms, and center-bolt valve covers. Many people, especially those with L-48, would be changing the intake and valve covers anyway.
The Vortecs are nothing short of phenomenal. But they do have several short comings. The lift is one, but is easy overcome. The others are the fact that a vortec style intake is needed, self-aligning rockers arms, and center-bolt valve covers. Many people, especially those with L-48, would be changing the intake and valve covers anyway.
Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
BTW, what do you think is better:
1. using stock vortec heads with the factory GM valve seals and the Crane LT-1 springs that mandm1200 mentioned.
2. buying SDPC heads machined for Z28 springs and aftermarket seals.
The price is within $5 for each option
Joe
1. using stock vortec heads with the factory GM valve seals and the Crane LT-1 springs that mandm1200 mentioned.
2. buying SDPC heads machined for Z28 springs and aftermarket seals.
The price is within $5 for each option
Joe
Le Mans Master
Joined: Mar 2002
Posts: 7,456
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From: Coming home from Luckenbach Texas
This is one of the reasons I passed on the Vortec heads and went with the Summit Racing (aka Dart Iron Eagle S/S) heads. Many aftermarket heads -- including these -- have the high-swirl combustion chamber that makes Vortecs so potent. Look for a kidney-shaped or heart-shaped combustion chamber. 
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Originally Posted by joe73vette
BTW, what do you think is better:
1. using stock vortec heads with the factory GM valve seals and the Crane LT-1 springs that mandm1200 mentioned.
2. buying SDPC heads machined for Z28 springs and aftermarket seals.
The price is within $5 for each option
Joe
1. using stock vortec heads with the factory GM valve seals and the Crane LT-1 springs that mandm1200 mentioned.
2. buying SDPC heads machined for Z28 springs and aftermarket seals.
The price is within $5 for each option
Joe
Instructor
Joined: May 2004
Posts: 183
Likes: 0
From: Lower Burrell PA
Originally Posted by mandm1200
The vortec heads are about the best bang for the buck when on a limited budget. They not only out perform other iron heads but many alum heads as well until you get into the larger cc alum heads. The stock Vortec head should handle a cam with up to .480 lift. I believe the sallee spec is a misprint. There is a simple upgrade to increase the max valve lift and that is to switch the springs to Cranes's 10309-1. With these springs you can go to a cam with .550 lift.
The Vortecs are nothing short of phenomenal. But they do have several short comings. The lift is one, but is easy overcome. The others are the fact that a vortec style intake is needed, self-aligning rockers arms, and center-bolt valve covers. Many people, especially those with L-48, would be changing the intake and valve covers anyway.
The Vortecs are nothing short of phenomenal. But they do have several short comings. The lift is one, but is easy overcome. The others are the fact that a vortec style intake is needed, self-aligning rockers arms, and center-bolt valve covers. Many people, especially those with L-48, would be changing the intake and valve covers anyway.
http://www.cranecams.com/index.php?s...1&lvl=2&prt=34
Instructor
Joined: May 2004
Posts: 183
Likes: 0
From: Lower Burrell PA
Found this from a previous thread:
Not sure, but these springs seem like they are for LT-1 heads, and all of the research I have done, are not interchangable on any "regular" small block. Any article I have read states that the valve guides need to be machined down on the vortec heads as the rocker will bottom out on any thing greater than .480, resulting in bad things, bent push rods, etc.
http://www.automotiverebuilder.com/ar/ar99928.htm
I have attached an article on the LT1/LT4 and under head gasket section it explains that the heads are not interchangable
http://www.jegs.com/cgi-bin/ncommer...226&prmenbr=361
Jegs shows the part # for these springs and the application as LT-1 iron heads. I just don't want to see anyone destroy a motor. I think the price to have a used set machined, 3/8" screw in studs and machined for the larger lift is around $350 at a local machine shop. Any article you read will tell you you have a great deal in these heads. My 2cents worth.......
Not sure, but these springs seem like they are for LT-1 heads, and all of the research I have done, are not interchangable on any "regular" small block. Any article I have read states that the valve guides need to be machined down on the vortec heads as the rocker will bottom out on any thing greater than .480, resulting in bad things, bent push rods, etc.
http://www.automotiverebuilder.com/ar/ar99928.htm
I have attached an article on the LT1/LT4 and under head gasket section it explains that the heads are not interchangable
http://www.jegs.com/cgi-bin/ncommer...226&prmenbr=361
Jegs shows the part # for these springs and the application as LT-1 iron heads. I just don't want to see anyone destroy a motor. I think the price to have a used set machined, 3/8" screw in studs and machined for the larger lift is around $350 at a local machine shop. Any article you read will tell you you have a great deal in these heads. My 2cents worth.......
Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
Sallee Chevrolet says you can use them on vortecs:
http://www.sallee-chevrolet.com/Cyli...ds/Vortec.html
scroll down to the article at the bottom:
"Once these machining operations have been completed, you have the choice of several aftermarket valvesprings to match your cam profile. These machining operations will produce enough clearance to allow between 0.525- and 0.550-inch valve lift before running into valvespring coil-bind. Given a 1.440-inch valvespring seat diameter, Comp and Crane offer several single and dual springs that will work with the stock valves.
Inserted by Sallee Chevrolet
The Sallee Chevrolet solution is to use Crane Cam’s 10309-1 drop-in valve spring and retainer kit which is good for .550” lift with no machining."
??? Joe
http://www.sallee-chevrolet.com/Cyli...ds/Vortec.html
scroll down to the article at the bottom:
"Once these machining operations have been completed, you have the choice of several aftermarket valvesprings to match your cam profile. These machining operations will produce enough clearance to allow between 0.525- and 0.550-inch valve lift before running into valvespring coil-bind. Given a 1.440-inch valvespring seat diameter, Comp and Crane offer several single and dual springs that will work with the stock valves.
Inserted by Sallee Chevrolet
The Sallee Chevrolet solution is to use Crane Cam’s 10309-1 drop-in valve spring and retainer kit which is good for .550” lift with no machining."
??? Joe
Last edited by joe73vette; Jan 2, 2005 at 10:54 PM.
Burning Brakes
Joined: Aug 2002
Posts: 1,146
Likes: 10
From: Scottsboro Alabama
You are correct Joe, BTW I have a set of Comp Cams #26918-16 LS1 beehive springs that I am going to install in my aluminum fast burn vortecs. Here's a discussion on the L31 vortecs...
http://www.sallee-chevrolet.com/Disc...tml?1097606367
http://www.sallee-chevrolet.com/Disc...tml?1097606367