Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

Heads question

Old Feb 15, 2013 | 12:54 AM
  #1  
transwiz's Avatar
Thread Starter
TECH Enthusiast
iTrader: (26)
 
Joined: May 2006
Posts: 648
Likes: 1
Default Heads question

If I have a set of 243 heads with stage one porting with 2.00" (stock valve
size) verses an identical set with 2.O2" and 1.57" exhaust how much app,
horsepower to the wheels difference would there be.
346 ls1 with 224 cam,ls6 intake,kooks long tubes and high flow cats,and
a good dyno tune.

The reason I am asking is a machine shop I talked to said that It would not
be worth it to install the 2.02" etc valves . He said the horsepower difference
would not make the work worth the money. I don't think I believe him.
A friend of mine says that it would be about 20 hp at the wheels. What do you
guys think?
Reply
Old Feb 15, 2013 | 04:30 AM
  #2  
PREDATOR-Z's Avatar
TECH Senior Member
 
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Default

Your machine shop is correct. 2.0 valves on stock cubes is plenty. A 2.02 valve will only flow maybe 10cfm more than stock 2.0.
Reply
Old Feb 15, 2013 | 08:05 AM
  #3  
onefast84's Avatar
9 Second Club
 
Joined: Aug 2009
Posts: 314
Likes: 0
From: Michigan
Default

So how much horse power do you think is 10 cfm worth? This seems interesting on what people think 10 cfm is worth.
Reply
Old Feb 15, 2013 | 08:14 AM
  #4  
TurboMonte100's Avatar
Launching!
iTrader: (1)
 
Joined: Nov 2012
Posts: 201
Likes: 0
From: Central Indiana
Default

A 10 cfm increase with everything else perfect and in the upper rpm ranges can produce 2.57 hp per cylinder, so times 8 would be 20.56 hp flywheel.

I agree with your machine shop.
Reply
Old Feb 15, 2013 | 09:38 AM
  #5  
batboy's Avatar
11 Second Club
iTrader: (6)
 
Joined: Feb 2005
Posts: 1,309
Likes: 2
From: middle of nowhere, Kansas
Default

With the 2.02 valves, you'll gain a little more intake flow at high rpm, maybe 5-10 hp. The heavier valve might limit your redline a bit. Looking at your signature mods, I probably would not worry about stepping up to a larger valve.
Reply
Old Feb 15, 2013 | 10:44 AM
  #6  
97camaro383's Avatar
12 Second Club
10 Year Member
iTrader: (31)
 
Joined: Oct 2010
Posts: 589
Likes: 0
From: Kansas City, MO
Default

Im kind of in the same situation, I can't decide if I should use stock valves or have TEA put the 2.04int 1.575 ext valves in. Also should I get turned down ls3 valves or just have TEA put the manley valves in. What are the power benefits of the 2.04 vs the 2.00 and when does shrouding start to become a issue?
Reply
Old Feb 15, 2013 | 12:34 PM
  #7  
Rise of the Phoenix's Avatar
TECH Senior Member
iTrader: (27)
 
Joined: Dec 2009
Posts: 9,728
Likes: 13
From: Jefferson City, MO
Default

PREDATOR-Z, I'd love to get your input on CND'd 243 heads. I know AI uses stock sized valves with both their 226cc and 232cc programs and TEA uses larger valves in their Stage 2 ported heads. I looked at the flow numbers and the TEA heads flow better, but what is your opinion on which of the two is better? I've seen many of your threads with great results from AI heads. I guess I'm asking is there going to be much HP/TQ difference between the TEA Stage 2 heaeds and the AI 232cc heads?
Reply
Old Feb 15, 2013 | 01:54 PM
  #8  
PREDATOR-Z's Avatar
TECH Senior Member
 
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Default

The only way to truly answer that is to flow them back to back under same conditions.
Both are good products.
Personally I'm a fan of light moving valve-train, meaning light valves, retainers and beehives. (Perhaps part of the reason I've no issues controlling harsh ramps at reasonable rpms)
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-1

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-2

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-3

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-4

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-5

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-6

10 Camaros You Should Never Buy

 
story-7

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
story-8

Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

 Brett Foote
story-9

10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

 Verdad Gallardo


Thread Tools
Search this Thread

All times are GMT -5. The time now is 01:32 AM.

story-0
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-1
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-2
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-3
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-4
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-5
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-6
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-7
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE
story-8
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

The world was a better place when it was still around.

By Brett Foote | 2026-01-23 09:20:37


VIEW MORE
story-9
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

Slideshow: The 7.0-liter LS7 was designed for absolute cutting-edge performance.

By Verdad Gallardo | 2026-01-07 18:36:00


VIEW MORE