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

Build a ls1 347 or ls2 shortblock???

Thread Tools
 
Search this Thread
 
Old May 21, 2006 | 06:11 PM
  #1  
a98ws6's Avatar
Thread Starter
TECH Addict
iTrader: (48)
 
Joined: Aug 2003
Posts: 2,272
Likes: 1
From: KCMO
Default Build a ls1 347 or ls2 shortblock???

I am going to order a shortblock soon and I had planned on just having a 347 ls1 built but for $3-400 more I could have a ls2(stock cube) shortblock built. What if any gains would I see from the ls2. Is it worth the extra $$$ for the conversion? I will be on stock heads for atleast one year also. (243) Going to be N/A. Help me decide! Thanks!
Reply
Old May 21, 2006 | 06:41 PM
  #2  
LS1-450's Avatar
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default

New LS6 assembled block w/L7 pistons. They show up on e-bay from time to time. Usually left overs from new owners modifying the engine right when they purchase the car. I bought one blue printed for $1,995.00. Purchased the timing set & gaskets seperately. Is the LS2 worth the weight increase?
Reply
Old May 21, 2006 | 09:39 PM
  #3  
ssam98's Avatar
TECH Regular
iTrader: (5)
 
Joined: Jan 2004
Posts: 437
Likes: 0
From: nyc
Default

Originally Posted by a98ws6
I am going to order a shortblock soon and I had planned on just having a 347 ls1 built but for $3-400 more I could have a ls2(stock cube) shortblock built. What if any gains would I see from the ls2. Is it worth the extra $$$ for the conversion? I will be on stock heads for atleast one year also. (243) Going to be N/A. Help me decide! Thanks!
The ls2, bigger cubes more tq.
Reply
Old May 21, 2006 | 09:50 PM
  #4  
Chicago Crew UnderBoss's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Oct 2002
Posts: 1,851
Likes: 0
From: Elmhurst, IL (Chicago Suburb)
Default

I agree, if your going to stay N/A the bigger cubes is a no brainer and better yet, if you can stroke it to 402 you will make huge power. I am running F/I with a D1SC so in a f/i appliation i would tell you a 346/7 that is blown or turbo charged will make more power than one will ever use on the street, but N/A you want the most cubes you can get and the bigger the better!!

Last edited by MTI 427 C5 Roadster; May 22, 2006 at 12:31 AM.
Reply
Old May 21, 2006 | 10:18 PM
  #5  
JakeFusion's Avatar
Super Hulk Smash
20 Year Member
Liked
Loved
Community Favorite
iTrader: (7)
 
Joined: Aug 2004
Posts: 11,258
Likes: 146
From: Pace, FL
Default

LS2 is only about 15lbs heavier (if I remember correctly)--and that's because it's a much stronger block. I'd go LS2 and maybe even look into a 402. Good 402 short-blocks run around 3800 or so. A forged 347 is going to be about $2800-3000, even if you have a core. You'd be better off selling the LS1 block to offset the price difference on the stroker crank with the 402 LS2.
Reply
Old May 21, 2006 | 10:25 PM
  #6  
snake charmer's Avatar
TECH Fanatic
iTrader: (118)
 
Joined: Sep 2004
Posts: 1,510
Likes: 1
From: The south
Default

There is no replacement for displacement ! Go with the cubes !
Reply
Old May 21, 2006 | 10:35 PM
  #7  
chevynation's Avatar
On The Tree
15 Year Member
iTrader: (8)
 
Joined: Jan 2006
Posts: 143
Likes: 0
From: AZ
Default

on the 402. then you can throw on a set of 4in ET ls7s + ls7 intake and make insane power. very light wallet though
Reply
Old May 21, 2006 | 10:43 PM
  #8  
SSilverSSurfer's Avatar
TECH Fanatic
iTrader: (8)
 
Joined: Jul 2004
Posts: 8,182
Likes: 0
From: College Station/Pasadena
Default

stroner..id do a 427 LS2
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
Old May 22, 2006 | 07:06 AM
  #9  
a98ws6's Avatar
Thread Starter
TECH Addict
iTrader: (48)
 
Joined: Aug 2003
Posts: 2,272
Likes: 1
From: KCMO
Default

Ok but heres the thing. I could hold off a little while and go LS2 and MAYBE save a little more for a 402, but will the stock LS1 (243's) kill the power? This is going to be a 90% drag car but still streetable. Not a DD. Just wont have the $$$ to do a ls2-402 and heads. Also what are my options for a cheap intake if I go to a LS2 block? Was looking at a TREX cam for the 347, but I would figure that would change if I go more cubes??
Thanks for all the help guys!
Reply
Old May 22, 2006 | 07:27 AM
  #10  
300bhp/ton's Avatar
TECH Addict
20 Year Member
Liked
Loved
 
Joined: Jun 2005
Posts: 2,660
Likes: 14
From: England
Default

What's heppening to the heads listed in your sig?

As for power increase, yes there's no replacement for displacement. However there is an easy bit of Maths you can employ.

The LS2 is essentiall the same as the LS1 just more displacement, so it means each engine can acheive very similar specific outputs.

At 100bhp/litre state of tune a 346ci would be making 570bhp, while a 6.0 Ls2 in the same state of tune would be making 600bhp. However running these engines at this state of tune n/a is unlikely for most.

Taking you sig number of 430rwhp that means you're probably in the region of 500bhp flywheel. So your specific output would be about (500 / 5.7) 88bhp/litre. So a 6.0 lump running the same state of tune would give you somewhere around (88 x 6) 528bhp.

Personally I'd go for a 402ci aluminium block with forged internals. However if handling isn't your thing then a 408ci ccast iron block is slightly cheaper.

A 402ci running about the same state of tune should be seeing 580bhp, so a fairly decent hike over a 346ci unit. Also you can always up the anti and run the new engine in a more extreme state of tune.
Reply
Old May 22, 2006 | 07:47 AM
  #11  
a98ws6's Avatar
Thread Starter
TECH Addict
iTrader: (48)
 
Joined: Aug 2003
Posts: 2,272
Likes: 1
From: KCMO
Default

The heads in my sig are long gone. I had to sell them cause the motor in my sig BLEW UP and I have to get some $$$ for this new engine so off they went. I would like to get heads next year but this year is just out of the question. If I do anything it will be an aluminum block. This is going to be in a somewhat light weight car also, with possibly a TH-350 and a 4500 stall.
Reply
Old May 22, 2006 | 03:47 PM
  #12  
a98ws6's Avatar
Thread Starter
TECH Addict
iTrader: (48)
 
Joined: Aug 2003
Posts: 2,272
Likes: 1
From: KCMO
Default

Ls1 heads use the same head studs as a ls2?
Reply
Old May 22, 2006 | 04:40 PM
  #13  
SSilverSSurfer's Avatar
TECH Fanatic
iTrader: (8)
 
Joined: Jul 2004
Posts: 8,182
Likes: 0
From: College Station/Pasadena
Default

brandon the moderator had stock LS1 heads on his 408 and it made close to 500
Reply




All times are GMT -5. The time now is 08:01 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