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

5.3L LM7 Maximum Safe Bore?

Thread Tools
 
Search this Thread
 
Old Jan 7, 2009 | 09:35 AM
  #1  
Black98Fivespeed's Avatar
Thread Starter
Teching In
iTrader: (2)
 
Joined: Dec 2007
Posts: 30
Likes: 0
Default 5.3L LM7 Maximum Safe Bore?

I'm picking up an LM7 block this weekend to start building for an eventual swap into my sixxer Camaro. I've seen that people have bored them out to around 3.9" before, but I was wondering if anyone has seen them bored to 4.00"+? I would guess it's possible since the block only has slight variations from it's LSx brothers, but wanted to see if anyone has input. I'm trying to decide if I want to stick with 327ci or bump it up a bit and go 11.5:1+ with the 5.3L heads.
Reply
Old Jan 7, 2009 | 12:29 PM
  #2  
5_02ls1's Avatar
11 Second Club
iTrader: (20)
 
Joined: Oct 2006
Posts: 3,131
Likes: 0
From: Virginia
Default

a safe bore would be the stock 346 3.898 bore if you wanna go 3.905 the block needs sonic tested...but 3,898 is a safe point...im doing the same thing...
Reply
Old Jan 7, 2009 | 12:48 PM
  #3  
Black98Fivespeed's Avatar
Thread Starter
Teching In
iTrader: (2)
 
Joined: Dec 2007
Posts: 30
Likes: 0
Default

So above 4.00" would be an absolute no-no or has no one even tried it? From my understanding the iron block should be stronger than an aluminum LS1 block, and not much different structurally, and those have been bored well over correct?
Reply




All times are GMT -5. The time now is 03:38 PM.

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