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

How far can you mill 243s?

Thread Tools
 
Search this Thread
 
Old Dec 3, 2008 | 12:19 PM
  #1  
poolshark021's Avatar
Thread Starter
12 Second Club
iTrader: (8)
 
Joined: Nov 2004
Posts: 205
Likes: 0
From: Royal Oak, MI
Default How far can you mill 243s?

As the title says, how far can you mill a set of 243s before valve shrouding becomes a problem? I have a friend who has a set milled .040 that he will sell me cheap. They would go on my 346 and I am already planning on flycutting the pistons. Would it be worth it if they were cheap enough or should I stay away?
Reply
Old Dec 3, 2008 | 03:30 PM
  #2  
Sigforty's Avatar
11 Second Club
20 Year Member
 
Joined: Jun 2005
Posts: 1,537
Likes: 0
From: Was New Orleans, but swam to Baton Rouge
Default

I have mine milled down to 58 cc chambers. They have close to 50 thou removed from them.
Reply
Old Dec 5, 2008 | 09:38 AM
  #3  
poolshark021's Avatar
Thread Starter
12 Second Club
iTrader: (8)
 
Joined: Nov 2004
Posts: 205
Likes: 0
From: Royal Oak, MI
Default

Sigforty is that on a 3.9" bore? What are your cam specs? Anyone else have an opinion?
Reply
Old Dec 5, 2008 | 10:19 AM
  #4  
ZFSix's Avatar
TECH Regular
iTrader: (14)
 
Joined: Jul 2005
Posts: 477
Likes: 0
From: Spring, TX
Default

They are already a 64cc, what are you trying to get? Mine are milled to 62cc to achieve the compression I was after but I also have a built bottom end with big valve reliefs. I was misled when I had them milled or else I wouldn't have spent the extra $150 for 2cc's.
Reply
Old Dec 5, 2008 | 10:24 AM
  #5  
Sigforty's Avatar
11 Second Club
20 Year Member
 
Joined: Jun 2005
Posts: 1,537
Likes: 0
From: Was New Orleans, but swam to Baton Rouge
Default

Originally Posted by poolshark021
Sigforty is that on a 3.9" bore? What are your cam specs? Anyone else have an opinion?
3.905 bore, -7 cc pistons and a 244 / 250 cam with .646 lift.
Reply
Old Dec 5, 2008 | 10:34 AM
  #6  
poolshark021's Avatar
Thread Starter
12 Second Club
iTrader: (8)
 
Joined: Nov 2004
Posts: 205
Likes: 0
From: Royal Oak, MI
Default

These have 58cc chambers if I did the math right... if they were mine stock there's no way would mill that far but since they're already done I don't have a choice. This would be on a rebuilt 346 lower end and a medium size cam (TR230 230/224 .580 i think). I figure my compression to be around 10.8:1 with stock gaskets and a small flycut.
Reply
Old Dec 6, 2008 | 08:28 AM
  #7  
LS1C5Vette's Avatar
TECH Resident
iTrader: (11)
 
Joined: Jan 2007
Posts: 836
Likes: 0
From: Oklahoma City
Default

Prob more like 11.0:1
Reply




All times are GMT -5. The time now is 04:39 PM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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-9
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