Generation IV Internal Engine 2005-2014 LS2 | LS3 | LS7 | L92 | LS9

compression for ls3 head swap

Thread Tools
 
Search this Thread
 
Old Mar 18, 2013 | 01:44 AM
  #1  
cr250r's Avatar
Thread Starter
On The Tree
iTrader: (4)
 
Joined: Dec 2012
Posts: 114
Likes: 0
From: FT. RILEY KS
Default compression for ls3 head swap

hi guys is have a 2005 gto i have the ls3 heads, intake, new cam chain, rockers, pedestals,headers im getting injectors and a pat g or ed curtis cam and matching valve train anyways im thinking of using a thinner head gasket .040 and milling the heads .020 over to get a compression ratio somewhere a little north of 11:1 i do realise that i will probly need to fly cut car will be weekend toy and plan on winding it out to 6500-6700 rpm so drivablilty isnt the biggest concern of those who have similar setups how do you like them?
Reply
Old Mar 18, 2013 | 07:00 AM
  #2  
litle88's Avatar
12 Second Club
15 Year Member
iTrader: (20)
 
Joined: Jan 2007
Posts: 2,561
Likes: 4
From: Burbank, Illinois
Default

I would not go anything tighter than an 11-1 due to valve shrouding. That's just my .2
Reply
Old Mar 18, 2013 | 07:50 AM
  #3  
low2001gmc's Avatar
MASS seller approved
15 Year Member
Liked
Loved
Community Favorite
iTrader: (150)
 
Joined: Jul 2007
Posts: 1,504
Likes: 180
From: ELSA, South TEXAS (956) 802-7700
Default

i milled my heads .015 and used cometic .040s for near 11:1 on my lq9 with ls3 heads. popular cam for gtos with ls2 with ls3 heads is ed curtis fti tigershark, 232-236, 600-600, 113. not sure on what them gto guys milled or gaskets used but the cometics .040 i would highly recommend as they help with quench and prevent detonation. anyway, google "fti tigershark cam gto" and youll find some threads on it with pb______ running 11.23 at 120....good luck with your project and hope this info helps....
Reply
Old Mar 18, 2013 | 10:22 AM
  #4  
FryZ71's Avatar
TECH Regular
 
Joined: Dec 2004
Posts: 487
Likes: 0
From: Da 'Cuse, NY
Default

My L92 heads are milled .030 w/ GM gaskets so close to the stock CR in my LS2 GTO. Running a cam from Ed at FTI, no flycutting.
Reply
Old Mar 20, 2013 | 11:14 PM
  #5  
cr250r's Avatar
Thread Starter
On The Tree
iTrader: (4)
 
Joined: Dec 2012
Posts: 114
Likes: 0
From: FT. RILEY KS
Default

Gmc I do agree with the thinner gasket to help fight detonation, how much to mill the heads for 11.25:1? Im hoping compression will boost bottom end pull maybe mill .018?
Reply




All times are GMT -5. The time now is 04:06 AM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
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-7
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-8
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-9
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