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

Difference between 241 and 243 castings?

Thread Tools
 
Search this Thread
 
Old Jan 10, 2006 | 07:27 PM
  #1  
FUN LS1's Avatar
Thread Starter
TECH Enthusiast
 
Joined: Jul 2005
Posts: 732
Likes: 0
From: Herndon, VA
Default Difference between 241 and 243 castings?

Whats the difference between the 241 and 243 castings?
Reply
Old Jan 10, 2006 | 07:42 PM
  #2  
orangeapeel's Avatar
ЯєŧąяĐ Єl¡m¡иąŧøя ™
iTrader: (18)
 
Joined: Nov 2004
Posts: 16,083
Likes: 4
From: Justin, TX
Default

241 is LS1 casting and 243 is Ls6....i believe...
Reply
Old Jan 10, 2006 | 09:41 PM
  #3  
Xtnct00WS6's Avatar
TECH Fanatic
iTrader: (8)
 
Joined: Jan 2005
Posts: 1,429
Likes: 2
From: Sterling VA
Default

Originally Posted by orangeapeel
241 is LS1 casting and 243 is Ls6....i believe...
Sounds right to me.

To add on to this a bit... The 243 makes a higher compression and flows better.

LS6 on the left and LS1 on the right:

Reply
Old Jan 10, 2006 | 09:59 PM
  #4  
777's Avatar
777
TECH Senior Member
iTrader: (21)
 
Joined: Jun 2004
Posts: 6,697
Likes: 2
From: Jacksonville, FL
Default

Casting Number 243
Head: 2001 LS6 5.7 Litre Passenger Car
Material: Aluminimum
Part Number:
12564243
Combustion Chamber Volume: 64.45cc
Compression Ratio: 10.5:1
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Casting Number 241
Head: 1997+ LS1 5.7 Litre Passenger Car
Material: Aluminimum
Part Number:
12559806 (1997-98) Chambers = 69cc
12559853 (1999-00)
12564241 (2001-03)
Combustion Chamber Volume: 66.67cc
Compression Ratio: 10.1:1
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches
Reply
Old Jan 10, 2006 | 10:01 PM
  #5  
JZ'sTA's Avatar
Banned
iTrader: (23)
 
Joined: Jan 2004
Posts: 3,126
Likes: 2
From: Ft. Myers Fl
Default

Originally Posted by Xtnct00WS6
Sounds right to me.

To add on to this a bit... The 243 makes a higher compression and flows better.

LS6 on the left and LS1 on the right:




True.....

The 243 casting is also used on the LS2 motor. It is interchangeable with the LS1, LS6, LS2, 6.0, 5.3, and 4.8 motor's as all the heads just listed bolt on to eachother's bottomend.
The LS6 head is a 64cc head where as the LS1 (241 casting as well as 806, and 853 casting) is a 67.67cc's. The difference is compression.
The 64 cc head will give about 1/2 a point more compression on a stcok LS1/LS6 motor.
There is a ton of reading on this subject. Check out JRP's common asked questions and read until your eyes fall out.
Reply
Old Jan 10, 2006 | 10:32 PM
  #6  
FUN LS1's Avatar
Thread Starter
TECH Enthusiast
 
Joined: Jul 2005
Posts: 732
Likes: 0
From: Herndon, VA
Default

Originally Posted by 777
Casting Number 243
Head: 2001 LS6 5.7 Litre Passenger Car
Material: Aluminimum
Part Number:
12564243
Combustion Chamber Volume: 64.45cc
Compression Ratio: 10.5:1
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Casting Number 241
Head: 1997+ LS1 5.7 Litre Passenger Car
Material: Aluminimum
Part Number:
12559806 (1997-98) Chambers = 69cc
12559853 (1999-00)
12564241 (2001-03)
Combustion Chamber Volume: 66.67cc
Compression Ratio: 10.1:1
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches
That's exactly what I was looking for. Thanks.

I wondered about the Intake Port volume especially...
Reply
Old Jan 11, 2006 | 09:03 AM
  #7  
Gunnar@Patriot's Avatar
FormerVendor
iTrader: (20)
 
Joined: Jul 2004
Posts: 1,416
Likes: 0
Default

The 97-98 806 castings will be the perimeter while all other 99-up heads will be center bolt. If you are going to be looking at ported heads, make sure to ask about the runner volume after porting. It can vary greatly. We have seen ported LS1 heads with runner volumes larger than our LS6 style heads.
Reply
Old Jan 11, 2006 | 09:30 AM
  #8  
FUN LS1's Avatar
Thread Starter
TECH Enthusiast
 
Joined: Jul 2005
Posts: 732
Likes: 0
From: Herndon, VA
Default

Originally Posted by Gunnar@Patriot
The 97-98 806 castings will be the perimeter while all other 99-up heads will be center bolt. If you are going to be looking at ported heads, make sure to ask about the runner volume after porting. It can vary greatly. We have seen ported LS1 heads with runner volumes larger than our LS6 style heads.
Thanks, Gunnar. That seems like it might be counter-productive on a 346 that's not blown or sprayed... I was trying to decide whether to port my stock heads, since I have the 241's, or to buy a set of ported and polished 243's (or LS6 style heads) outright. I wanted to keep the velocity up, so I was concerened about getting the intake runner volume upwards of 225cc's, where I'll lose some mid-range torque. I have 4.10's and I'm not too worried about losing low-end torque. I guess if I buy new ones, I can sell my 241's to help pay for the upgrade...
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

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

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

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

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Jan 11, 2006 | 09:43 AM
  #9  
Gunnar@Patriot's Avatar
FormerVendor
iTrader: (20)
 
Joined: Jul 2004
Posts: 1,416
Likes: 0
Default

Make sure to take a look at our 243 catings that we have right now.
Reply
Old Jan 11, 2006 | 10:06 AM
  #10  
FUN LS1's Avatar
Thread Starter
TECH Enthusiast
 
Joined: Jul 2005
Posts: 732
Likes: 0
From: Herndon, VA
Default

Originally Posted by Gunnar@Patriot
Make sure to take a look at our 243 catings that we have right now.
Yeah, I read a bunch of posts about them, and it sounds like a sweet deal with those valves. I couldn't find the page for them on your web site, though. Just the LS6 Style and 5.3/LS1 pages...
Reply
Old Jan 11, 2006 | 10:49 AM
  #11  
Gunnar@Patriot's Avatar
FormerVendor
iTrader: (20)
 
Joined: Jul 2004
Posts: 1,416
Likes: 0
Default

Originally Posted by FUN LS1
Yeah, I read a bunch of posts about them, and it sounds like a sweet deal with those valves. I couldn't find the page for them on your web site, though. Just the LS6 Style and 5.3/LS1 pages...
Tehy aren't on there. Haven't had time to go on and add them in. If you have any questions about them, please let us know.
Reply
Old Jan 11, 2006 | 02:16 PM
  #12  
DavidNJ's Avatar
TECH Resident
 
Joined: Dec 2004
Posts: 881
Likes: 1
Default

LS6 on the left and LS1 on the right:



vs. this from AFR:



and the new LS7:

Attached Thumbnails Difference between 241 and 243 castings?-afr-chamber.jpg   Difference between 241 and 243 castings?-ls7-chamber.jpg  
Reply




All times are GMT -5. The time now is 09:20 AM.

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