Adding GMPP CNC LS6 Heads. . .Need advice!
Thread Starter
Race Director
Joined: Mar 2001
Posts: 10,665
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Adding GMPP CNC LS6 Heads. . .Need advice!
Ok,
So I've finally made up my mind, and after purchasing my 5th set of heads, I'm putting in the GM Performance Parts CNC LS6 Heads in my 98 Vert. They're complete with 02 springs, 02 Valves, etc, and I'm also adding an 02 LS6 Cam (I think lift is .550).
I've read that the GMPP heads are shaved .055 to .060 and was wondering if this will cause me any problem in the setup I'm going with. I had planned on using stock pushrods and stock rockers, so if this is a problem, please let me know.
What kind of compression should I expect when done? Also, any advice on the programming when it's ready to LS1 Edit?
Thanks Guys (and gals :)!
Josh
So I've finally made up my mind, and after purchasing my 5th set of heads, I'm putting in the GM Performance Parts CNC LS6 Heads in my 98 Vert. They're complete with 02 springs, 02 Valves, etc, and I'm also adding an 02 LS6 Cam (I think lift is .550).
I've read that the GMPP heads are shaved .055 to .060 and was wondering if this will cause me any problem in the setup I'm going with. I had planned on using stock pushrods and stock rockers, so if this is a problem, please let me know.
What kind of compression should I expect when done? Also, any advice on the programming when it's ready to LS1 Edit?
Thanks Guys (and gals :)!
Josh
Le Mans Master
Joined: Jan 2001
Posts: 5,786
Likes: 6
From: Lafayette Colorado
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (PaceThis)
With stock bore, stroke, and gasket thickness; I would guess your compression about be around 11.2:1. With LS1Edit, do not go tto aggressive on timing with that high of compression. If you do, you will need to run higher octane fuel( 95+ ) all the time.
Keith
Keith
Safety Car
Joined: Oct 2001
Posts: 3,504
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From: Insert Wittty Comment here
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (kromberg)
Just remember that the heads are milled that much because of all the chamber work. Those heads milled .055 are just like mosty other vendors heads milled .030. They end up with a 60-61cc combustion chamber.
Melting Slicks
Joined: Mar 2001
Posts: 2,369
Likes: 51
From: New Milford CT
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (J-Rod)
Just curious why you went with the stock 2002 Z06 cam?
I almost went Z06 cam also, until Andy and others told me I could use the TR 220/551/114 with the stock 2002 Z06 valve springs.
I almost went Z06 cam also, until Andy and others told me I could use the TR 220/551/114 with the stock 2002 Z06 valve springs.
Melting Slicks
Joined: Mar 2001
Posts: 2,809
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From: Frisco TX
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (CJS)
What kinda power did you make with that setup? Just curious as it is very sneaky.. :D
Just curious why you went with the stock 2002 Z06 cam?
I almost went Z06 cam also, until Andy and others told me I could use the TR 220/551/114 with the stock 2002 Z06 valve springs.
I almost went Z06 cam also, until Andy and others told me I could use the TR 220/551/114 with the stock 2002 Z06 valve springs.
Thread Starter
Race Director
Joined: Mar 2001
Posts: 10,665
Likes: 56
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (CJS)
Just curious why you went with the stock 2002 Z06 cam?
I almost went Z06 cam also, until Andy and others told me I could use the TR 220/551/114 with the stock 2002 Z06 valve springs.
I almost went Z06 cam also, until Andy and others told me I could use the TR 220/551/114 with the stock 2002 Z06 valve springs.
Drifting
Joined: May 2002
Posts: 1,607
Likes: 1
From: San Francisco CA
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (PaceThis)
According to Scoggin-Dickey these heads are milled .055. The stock rockers are ok but you will need different pushrods. According to Ed Potter of LPE (they make the heads), the pushrods are available through Scoggin-Dickey and the compression works out to be around 11.0 to 1 on motors with a stock bottom end, which is not a problem on the street.
Besides the pushrods, you will have to modify the intake manifold a bit. Not a big deal but there are two brass inserts on the intake. One at passenger side front and one at drivers side rear, they must be removed and machined .050. This will allow the intake to seal the gasket.
Besides the pushrods, you will have to modify the intake manifold a bit. Not a big deal but there are two brass inserts on the intake. One at passenger side front and one at drivers side rear, they must be removed and machined .050. This will allow the intake to seal the gasket.
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Melting Slicks
Joined: Mar 2001
Posts: 2,369
Likes: 51
From: New Milford CT
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (PaceThis)
I wanted to stay with stock 2002 Z06 valve springs (for reliability) so at first I just figured I would have to use the stock 2002 Z06 cam also.
Then I figured I would get a custom ground cam that was like stock Z06 but had more intake duration. Stock 2002 Z06 intake duration is only 207.
Then I realized the TR 220/551/114 was really close to what I wanted.
Similar cams I could have used are the MMS 218/261/114, the Cartek "M" cam 218/224/113.5, or the MTI B1 at 221/558/114 looked good too.
But there is alot of info on LS1dotcom on the TR 220 cam, so thats why I used it.
I did not ever use the stock 2002 Z06 cam.
There is no one on earth that would not like this TR cam, if they like a Z06 engine, it is very little different than that at idle, which is just a little more raggidy than stock LS1.
But mucho more pull at about 4000rpms. My engine is just as quiet as before, no valve train noise at all.
I am getting 3.90 gears in January, but I will not get a dyno until later on this winter.
Similar modded vettes are getting ~ 385 to 400 rwhp.
Good luck on your heads and cam, tell us how it comes out!
Then I figured I would get a custom ground cam that was like stock Z06 but had more intake duration. Stock 2002 Z06 intake duration is only 207.
Then I realized the TR 220/551/114 was really close to what I wanted.
Similar cams I could have used are the MMS 218/261/114, the Cartek "M" cam 218/224/113.5, or the MTI B1 at 221/558/114 looked good too.
But there is alot of info on LS1dotcom on the TR 220 cam, so thats why I used it.
I did not ever use the stock 2002 Z06 cam.
There is no one on earth that would not like this TR cam, if they like a Z06 engine, it is very little different than that at idle, which is just a little more raggidy than stock LS1.
But mucho more pull at about 4000rpms. My engine is just as quiet as before, no valve train noise at all.
I am getting 3.90 gears in January, but I will not get a dyno until later on this winter.
Similar modded vettes are getting ~ 385 to 400 rwhp.
Good luck on your heads and cam, tell us how it comes out!
Racer
Joined: Sep 2002
Posts: 420
Likes: 0
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (YOULLUZ)
Racer
Joined: Dec 2002
Posts: 351
Likes: 0
From: Sacramento area CA
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (SilverStateZ06)
Thanks Silverstate: How do these heads compare to ported heads offered by one of the vendors around here? At $985 each, you could have a smoking pair of heads for under $2k and have no core charge to deal with. The only thing that worries me is the up in compression. With this crappy California 91 octane IM thinking it would detonate very easily..
Melting Slicks
Joined: Mar 2001
Posts: 2,809
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From: Frisco TX
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (YOULLUZ)
These heads are absolute top quality for CNC'ed heads - please make no mistake..
However - as far as proven hand ported heads (Like MTI etc..) - they are still in another leauge.. and are still considered to be better than CNC'ed heads..
[Modified by bparker, 8:33 AM 12/31/2002]
However - as far as proven hand ported heads (Like MTI etc..) - they are still in another leauge.. and are still considered to be better than CNC'ed heads..
Thanks Silverstate: How do these heads compare to ported heads offered by one of the vendors around here? At $985 each, you could have a smoking pair of heads for under $2k and have no core charge to deal with. The only thing that worries me is the up in compression. With this crappy California 91 octane IM thinking it would detonate very easily..
[Modified by bparker, 8:33 AM 12/31/2002]
Drifting
Joined: Feb 2002
Posts: 1,630
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From: Park Ridge Illinois
2022 C5 of the Year Finalist - Modified
2021 C5 of the Year Finalist - Modified
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (bparker)
I've got these awesome looking heads and can't wait to put them on over the winter. The shorter pushrods that you'll need are the Comp Cams 7950-16. They are 5/16 7.350 .080 Wall. I'm going with the GT2-3 cam, 207/220 .573-.580 w/ 117.5 lobe because I see a Magnusson or turbo in my future. Thanks to Ed for setting me up :thumbs:
Drifting
Joined: Oct 2002
Posts: 1,289
Likes: 0
From: Decatur IN
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (Jason Blue Boost)
Pace this -
Sounds like the other members have your questions covered, since you're using LS1 edit, you should be able to tune around the compression issue. Feel free to give us a call if you need any advice.
Thanks Jason, I can't wait to get some boost to your Vette!
Ed
Sounds like the other members have your questions covered, since you're using LS1 edit, you should be able to tune around the compression issue. Feel free to give us a call if you need any advice.
Thanks Jason, I can't wait to get some boost to your Vette!
Ed
Drifting
Joined: May 2002
Posts: 1,607
Likes: 1
From: San Francisco CA
Re: Adding GMPP CNC LS6 Heads. . .Need advice! (YOULLUZ)
The only thing that worries me is the up in compression. With this crappy California 91 octane IM thinking it would detonate very easily..
