Newly Released GMPP CNC LS3 heads
Thread Starter
10 Second Club
iTrader: (15)
Joined: Nov 2001
Posts: 4,519
Likes: 0
From: St. Michael, MN.
Newly Released GMPP CNC LS3 heads I saw this on the LSX TV website. Looks interesting. It would be curious to see how these compared to aftermarket castings.
http://www.lsxtv.com/news/new-produc...ormance-parts/
http://www.lsxtv.com/news/new-produc...ormance-parts/
Do you want increased airflow for your LS engine? Look no further than GM Performance Parts and their new high-flow, CNC-Ported LS3 Cylinder Head. Not only will this head increase the flow of your LS3 engine, it can also be used on any LS engine bored to 4.0 inches.
Official Release:
GM Performance Parts Announces High-Flow, CNC-Ported LS3 Cylinder Head
GRAND BLANC, Mich. – GM Performance Parts’ (GMPP) has released a high-flow, CNC-ported version of the LS3 cylinder head. It flows more than 350 cfm at 0.600-inch lift (intake side) at 28 inches of water restriction – or nearly 10 percent more than the stock casting – to promote greater power across the rpm band and maximize the advantage of additional performance parts, such as a “larger” camshaft and high-flow intake manifold.
The new head carries part number 88958758 and an MSRP of $700. It is available now through GMPP dealers and retailers, including through the GM Performance Parts Web site: gmperformanceparts.com. CNC porting is a precision machining process that enlarges and optimizes the shape of the intake and exhaust ports to enhance airflow. And while a horsepower increase can be realized by installing only the heads, they are more effective when matched with complementing camshaft, valvetrain, intake and exhaust components.
“This new cylinder head is a great choice for builders looking to get the most out of a simple, bolt-on cam-and-heads swap on their new Camaro SS or Corvette,” said Dr. Jamie Meyer, product integration manager for GM Performance Parts. “It also complements a bolt-on supercharger by maximizing the airflow, particularly at higher rpm.”
GMPP engineers recommend the LS Hot Cam (part number 88958753)
or the high-rpm “ASA” camshaft (part number 88958770) as suitable partners with a set of CNC-ported LS3 heads. The LS Hot Cam delivers 0.525-inch of lift and 219/228 degrees of duration on a 112-degree lobe separation angle. The hotter ASA cam matches the 0.525-inch lift, but delivers 226/236 degrees duration on a tighter 110-degree lobe separation angle. Both camshafts are compatible with the valve springs included with the cylinder head assemblies.
Designed for airflow
The CNC-ported LS3 head features 276cc intake runners and 92cc exhaust ports, along with a combustion chamber volume of about 68.5cc. That’s the same volume as stock LS3 heads, which maintains the stock compression ratio. It will fit any LS engine with cylinder bores of 4.000 inches or larger, including 6.2L L92 truck engines.
Each head is delivered fully assembled, with 2.165-inch hollow-stem intake valves and 1.59-inch solid-stem exhaust valves, as well as valve springs, valve locks, spring retainers and valve stem seals. The maximum recommended valve lift with the stock valvetrain components is 0.550-inch.
Below are the airflow specifications for the CNC-ported LS3 head, based on flowbench testing conducted with 28 inches of water restriction.
LIFT (mm) LIFT (inch) CFM – INTAKE CFM – EXHAUST
1.0 0.039 27.612 21.037
2.0 0.079 60.714 44.679
3.0 0.118 87.300 75.053
4.0 0.157 124.341 103.872
5.0 0.197 161.414 127.083
6.0 0.236 195.628 147.451
7.0 0.276 223.566 167.097
8.0 0.315 251.641 186.501
9.0 0.354 275.218 206.322
10.0 0.394 294.406 222.840
11.0 0.433 311.917 234.353
12.0 0.472 327.475 242.617
13.0 0.512 340.917 247.045
14.0 0.551 348.538 249.514
15.0 0.591 351.323 252.371
16.0 0.630 359.135 255.246
17.0 0.669 365.137 257.451
18.0 0.709 361.738 259.690
19.0 0.748 364.504 260.962
20.0 0.787 369.196 262.666
Highlights:
Official Release:
GM Performance Parts Announces High-Flow, CNC-Ported LS3 Cylinder Head
GRAND BLANC, Mich. – GM Performance Parts’ (GMPP) has released a high-flow, CNC-ported version of the LS3 cylinder head. It flows more than 350 cfm at 0.600-inch lift (intake side) at 28 inches of water restriction – or nearly 10 percent more than the stock casting – to promote greater power across the rpm band and maximize the advantage of additional performance parts, such as a “larger” camshaft and high-flow intake manifold.
The new head carries part number 88958758 and an MSRP of $700. It is available now through GMPP dealers and retailers, including through the GM Performance Parts Web site: gmperformanceparts.com. CNC porting is a precision machining process that enlarges and optimizes the shape of the intake and exhaust ports to enhance airflow. And while a horsepower increase can be realized by installing only the heads, they are more effective when matched with complementing camshaft, valvetrain, intake and exhaust components.
“This new cylinder head is a great choice for builders looking to get the most out of a simple, bolt-on cam-and-heads swap on their new Camaro SS or Corvette,” said Dr. Jamie Meyer, product integration manager for GM Performance Parts. “It also complements a bolt-on supercharger by maximizing the airflow, particularly at higher rpm.”
GMPP engineers recommend the LS Hot Cam (part number 88958753)
or the high-rpm “ASA” camshaft (part number 88958770) as suitable partners with a set of CNC-ported LS3 heads. The LS Hot Cam delivers 0.525-inch of lift and 219/228 degrees of duration on a 112-degree lobe separation angle. The hotter ASA cam matches the 0.525-inch lift, but delivers 226/236 degrees duration on a tighter 110-degree lobe separation angle. Both camshafts are compatible with the valve springs included with the cylinder head assemblies.
Designed for airflow
The CNC-ported LS3 head features 276cc intake runners and 92cc exhaust ports, along with a combustion chamber volume of about 68.5cc. That’s the same volume as stock LS3 heads, which maintains the stock compression ratio. It will fit any LS engine with cylinder bores of 4.000 inches or larger, including 6.2L L92 truck engines.
Each head is delivered fully assembled, with 2.165-inch hollow-stem intake valves and 1.59-inch solid-stem exhaust valves, as well as valve springs, valve locks, spring retainers and valve stem seals. The maximum recommended valve lift with the stock valvetrain components is 0.550-inch.
Below are the airflow specifications for the CNC-ported LS3 head, based on flowbench testing conducted with 28 inches of water restriction.
LIFT (mm) LIFT (inch) CFM – INTAKE CFM – EXHAUST
1.0 0.039 27.612 21.037
2.0 0.079 60.714 44.679
3.0 0.118 87.300 75.053
4.0 0.157 124.341 103.872
5.0 0.197 161.414 127.083
6.0 0.236 195.628 147.451
7.0 0.276 223.566 167.097
8.0 0.315 251.641 186.501
9.0 0.354 275.218 206.322
10.0 0.394 294.406 222.840
11.0 0.433 311.917 234.353
12.0 0.472 327.475 242.617
13.0 0.512 340.917 247.045
14.0 0.551 348.538 249.514
15.0 0.591 351.323 252.371
16.0 0.630 359.135 255.246
17.0 0.669 365.137 257.451
18.0 0.709 361.738 259.690
19.0 0.748 364.504 260.962
20.0 0.787 369.196 262.666
Highlights:
- Over 10 percent more flow than the stock cylinder head
- Simple bolt on performance component
- Compliments a bolt-on supercharger
- Fits any LS engine with a bore of 4.0 inches
Last edited by DrkPhx; Aug 24, 2011 at 12:49 AM.
While their marketing is good, I have already dyno tested these heads and can tell you there are much better CNC'd LS3 heads available 
When you factor in the price of a good spring kit and milling to get them where you need them, you're at or above the price of the PRC (and other) CNC'd LS3 heads but with less power. Why spend the same money for less power?
When you factor in the price of a good spring kit and milling to get them where you need them, you're at or above the price of the PRC (and other) CNC'd LS3 heads but with less power. Why spend the same money for less power?
__________________
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
HMMM. I’ve just had a good read of the PRC237 that Jimbo mentioned over on the TSP website (thanks Matt!).
The PRC237 heads are a thousand bucks more for a pair vs. this new GM head. Both are fully assembled with valves and springs good for “big” cams but the GM head has larger (.065) hollow intake valves vs. the solid valves on the PRC head. I would consider both of these to be advantage: GM.
I’m certain you guys are right that the PRC head has more flow but for many guys bolting together an engine, this new GM head looks very very good for it’s price point and features.
The PRC237 heads are a thousand bucks more for a pair vs. this new GM head. Both are fully assembled with valves and springs good for “big” cams but the GM head has larger (.065) hollow intake valves vs. the solid valves on the PRC head. I would consider both of these to be advantage: GM.
I’m certain you guys are right that the PRC head has more flow but for many guys bolting together an engine, this new GM head looks very very good for it’s price point and features.
Trending Topics
[QUOTE=Matt@Texas-Speed;15308781]While their marketing is good, I have already dyno tested these heads and can tell you there are much better CNC'd LS3 heads available
Everyone's marketing is pretty good now days.
I'd love to see those tests.....what did you compare the results with? apples to apples, I hope
Everyone's marketing is pretty good now days.
I'd love to see those tests.....what did you compare the results with? apples to apples, I hope
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo Keep in mind on these, when you add a .650" lift spring kit and get them milled any (which is free when you order a PRC head), you will have spent as much if not more than the PRC heads cost!
__________________
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
Yes, we milled to ensure the same chambers size, same camshaft, same valve options, only the ports were changed. The results were as expected!
__________________
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
Unless any of the mentioned heads have fixed the LS3 valve centerlines (from factory location), I would suggest the Mast LS3 for an LS3 project. Other than that, buy any LS7 or an aftermarket cathedral port and you will run better. 
Flow numbers on a chart do not mean a head is going to make more power. If nothing else there are differences on flowing heads that increase flow numbers. So its very possible for a head that has lower flow numbers on a chart to make more power.
Yes absolutely... Factory LS3 heads produce about the same flow numbers or more than the heads I ran on my previous combo. I would bet the farm that if I put factory LS3 heads on that engine, it would not have laid down the times I ran before even with cam change. I would go ahead and say even ported factory castings wouldn't do it.
Yes I know that and I agree with you, hence why I asked them to prove it.
Why should TSP come on here and knock GM for their marketing when all they're doing is the same. He's bashing a budget GM head and then markets his PRC head by stating how much better it is.
Well if you're going to open your mouth, then prove it. Back it up.
i will say this, my prc ported STOCK ls3 castings do work on my motor, for under $1500. i dont have the cash to try out the aftermarket cast prc's.... TSP forged 402 11.7:1 244/256 cam 114lsa (pat g spec'd), stock intake, 92mm tb ,ARH 1 7/8 headers, 554rwhp 510rwtq. Relatively mild tune.
