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

Is Gen III hardware that bad?

Thread Tools
 
Search this Thread
 
Old 02-28-2017, 08:40 PM
  #1  
Teching In
Thread Starter
 
MrGame's Avatar
 
Join Date: Feb 2008
Location: NJ
Posts: 31
Received 8 Likes on 5 Posts

Question Is Gen III hardware that bad?

I have an LS1 GTO with a H/C/I 346 and TH400 combo, car has a 5400 stall and is set up for drag racing. It's a bracket car and I'm working with somewhat of a budget. I'm considering building a 383 with top notch heads (Black Label, TEA or Trickflow) and a single plane intake. I've talked to a few people that say it would be much, much better to go to a 4"+ bore from an LS2 or 3. I want to stay with an aluminum block since conserving weight is a major concern with a car that's so heavy to start with. The car has been 10.98 with the current combo, is a 383 with improved heads and a single plane really going to wake it up? People make it sound like Gen III is the oldest tech in the world, but there still seem to be a ton of fast LS1/6 motors running around
Old 03-01-2017, 05:13 PM
  #2  
TECH Addict
iTrader: (15)
 
Mercier's Avatar
 
Join Date: Jun 2014
Location: Baton Rouge, LA
Posts: 2,384
Likes: 0
Received 5 Likes on 5 Posts
Default

Gen III stuff isn't BAD but it is at a disadvantage when it comes to bore size and the resulting head availability.

If you're spending the same amount of $$ on a stroker kit, heads, etc., why not open yourself up to the possibility of spending a little more on a LS2 or LS3 block? The same spend on a stroker kit then gets you 400+ inches. Also allows LS3-type heads which do require a 4" bore minimum due to bigger valves.

If you'll spend for black label heads, why not a LS3 block for another $1000 and your stroker is now a 416 instead of a 383? To a certain extent also, bigger bore allows most heads to flow better.

FWIW, the stock LS3 heads flow more than most ported cathedral heads. The aftermarket has done some amazing things with the cath heads but still the max effort cath stuff is not that much ahead of the stock heads running around in grandpa's 6.2L Silverado.
Old 03-01-2017, 05:49 PM
  #3  
TECH Veteran
iTrader: (2)
 
wannafbody's Avatar
 
Join Date: Apr 2006
Location: Pittsburgh
Posts: 4,758
Received 850 Likes on 651 Posts

Default

Top of the line heads on a 3.9 inch bore are a waste. You really need a 4 inch bore to get the most out of aftermarket heads.
Old 03-01-2017, 07:15 PM
  #4  
TECH Apprentice
 
Fishmasterdan's Avatar
 
Join Date: Oct 2015
Posts: 309
Received 22 Likes on 17 Posts
Default

Budget to me means add some juice if your racing. 5.3 with 243 heads can get you into the 9 s anything faster than 9.99 gets into alot of extra dollars for the safety stuff.
To me if you set on a stroker about the best bang for the buck is an iron lq4 ,408. To stay all aluminum it gets spendy fast.
Old 03-01-2017, 07:19 PM
  #5  
TECH Senior Member
iTrader: (18)
 
TXsilverado's Avatar
 
Join Date: Jan 2005
Location: Humble Texas
Posts: 15,713
Likes: 0
Received 7 Likes on 4 Posts

Default

Skip the expense of blocks and heads and turbo the 5.7. More power for same or less money
Old 03-01-2017, 07:25 PM
  #6  
TECH Addict
iTrader: (15)
 
Mercier's Avatar
 
Join Date: Jun 2014
Location: Baton Rouge, LA
Posts: 2,384
Likes: 0
Received 5 Likes on 5 Posts
Default

Originally Posted by TXsilverado
Skip the expense of blocks and heads and turbo the 5.7. More power for same or less money
That's a fine idea as well! There was a GTO turbo kit in the classifieds in the last week or so.

Edit: here it is!

https://ls1tech.com/forums/parts-cla...-2006-gto.html

We can spend all of your money for you.
Old 03-01-2017, 07:32 PM
  #7  
Staging Lane
 
stonebreaker's Avatar
 
Join Date: Dec 2004
Location: Weatherford, TX
Posts: 65
Received 10 Likes on 9 Posts

Default

Originally Posted by wannafbody
Top of the line heads on a 3.9 inch bore are a waste. You really need a 4 inch bore to get the most out of aftermarket heads.
You guys are spoiled. Olde skool oval port big block heads don't flow as well as my ported cathedrals, and those heads will make 600+ hp on a 454.
Old 03-01-2017, 07:32 PM
  #8  
TECH Apprentice
 
Fishmasterdan's Avatar
 
Join Date: Oct 2015
Posts: 309
Received 22 Likes on 17 Posts
Default

Good luck going rounds with a turbo bracket car. To many variables with temperature as the day and track plays out. No impossible but difficult
Old 03-01-2017, 08:05 PM
  #9  
TECH Senior Member
iTrader: (4)
 
99 Black Bird T/A's Avatar
 
Join Date: Nov 2001
Posts: 8,601
Received 1,451 Likes on 1,007 Posts

Default

Originally Posted by MrGame
I have an LS1 GTO with a H/C/I 346 and TH400 combo, car has a 5400 stall and is set up for drag racing. It's a bracket car and I'm working with somewhat of a budget. I'm considering building a 383 with top notch heads (Black Label, TEA or Trickflow) and a single plane intake. I've talked to a few people that say it would be much, much better to go to a 4"+ bore from an LS2 or 3. I want to stay with an aluminum block since conserving weight is a major concern with a car that's so heavy to start with. The car has been 10.98 with the current combo, is a 383 with improved heads and a single plane really going to wake it up? People make it sound like Gen III is the oldest tech in the world, but there still seem to be a ton of fast LS1/6 motors running around

LS1/Gen3 383 strokers typically do not gain much if any hp over a well done forged 347. The strokers will normally gain 25 to 45 foot pounds of torque over the forged 347. This seems to be due to the 3.9 bore size the LS1/LS6 block is limited to and the restrictive intake manifolds typically required.

Often the 3.9 bore will limit the intake valve size to about 2.04 any bigger and the valve gets shrouded and does not flow as well.

My Brian Tooley hand finished TEA LS6 Stage 2.5 from 2003 could flow about 345 cfm (2.08 valve) on a 4.125 bore, 335 on a 4.0 bore and 320 (2.04 valve) 3.9 bore.
Why give up 25 cfm of air flow and potentially 45 to 60 hp by using a 3.9 bore?

I'm sure TEA's newer heads are even better nearly 15 years later.

I went with a 3.9 bore LS1 383 with the TEA's mentioned above and a small cam for my street driven 91 RS Camaro but if the RS was going to be a RACE care only a 4.125 bore block or bigger would have been acceptable to me for the above reasons.

Best wishes on the build.
Old 03-01-2017, 10:23 PM
  #10  
TECH Veteran
iTrader: (2)
 
wannafbody's Avatar
 
Join Date: Apr 2006
Location: Pittsburgh
Posts: 4,758
Received 850 Likes on 651 Posts

Default

Originally Posted by stonebreaker
You guys are spoiled. Olde skool oval port big block heads don't flow as well as my ported cathedrals, and those heads will make 600+ hp on a 454.
My neighbor is building a Ford 351W for his 82 Mustang. He was telling me about these super trick, double throw down heads that flow 300CFM. I told him a set of ported GM LS castings flow the same for less than half the price of the Ford head.
Old 03-02-2017, 08:22 AM
  #11  
TECH Addict
iTrader: (15)
 
Mercier's Avatar
 
Join Date: Jun 2014
Location: Baton Rouge, LA
Posts: 2,384
Likes: 0
Received 5 Likes on 5 Posts
Default

Originally Posted by wannafbody
My neighbor is building a Ford 351W for his 82 Mustang. He was telling me about these super trick, double throw down heads that flow 300CFM. I told him a set of ported GM LS castings flow the same for less than half the price of the Ford head.
Kick him while he's down...Tell him even the L92(truck) heads flow more than that bone stock. Lot of air for $450.

I wasn't always so spoiled; I was born a poor Mustang child and can remember grinding exhaust bumps out of cast iron E7TE heads on my '91 LX..That was a lot of labor for a handful of horsepower. Probably flowed a whopping 160CFM when I was done!
Old 03-02-2017, 10:52 AM
  #12  
TECH Junkie
iTrader: (5)
 
redtan's Avatar
 
Join Date: May 2008
Location: Belmont, MA
Posts: 3,764
Likes: 0
Received 16 Likes on 15 Posts

Default

You guys are spoiled. Olde skool oval port big block heads don't flow as well as my ported cathedrals, and those heads will make 600+ hp on a 454.
This exactly makes the point everyone has been trying to say. Bore size is very important to heads, and by your example a big bore/displacement can make power even with shitty heads. But a small bore/displacement with big $$$ heads will not make the same power.
Old 03-03-2017, 07:01 PM
  #13  
Teching In
Thread Starter
 
MrGame's Avatar
 
Join Date: Feb 2008
Location: NJ
Posts: 31
Received 8 Likes on 5 Posts

Default

I actually found a great deal on an LS2 block so looks like it's no longer a problem. I'm going to bore and stroke it out to 408 with some proper heads, a matching cam and a Super Vic intake. Should run well (I hope)
Old 03-03-2017, 09:59 PM
  #14  
TECH Addict
iTrader: (15)
 
Mercier's Avatar
 
Join Date: Jun 2014
Location: Baton Rouge, LA
Posts: 2,384
Likes: 0
Received 5 Likes on 5 Posts
Default

Originally Posted by MrGame
I actually found a great deal on an LS2 block so looks like it's no longer a problem. I'm going to bore and stroke it out to 408 with some proper heads, a matching cam and a Super Vic intake. Should run well (I hope)
Old 03-04-2017, 10:24 AM
  #15  
TECH Fanatic
iTrader: (5)
 
64post's Avatar
 
Join Date: Nov 2011
Location: Sonoma Co. Ca.
Posts: 1,693
Received 226 Likes on 179 Posts

Default

Originally Posted by 99 Black Bird T/A
LS1/Gen3 383 strokers typically do not gain much if any hp over a well done forged 347. The strokers will normally gain 25 to 45 foot pounds of torque over the forged 347. This seems to be due to the 3.9 bore size the LS1/LS6 block is limited to and the restrictive intake manifolds typically required.

Often the 3.9 bore will limit the intake valve size to about 2.04 any bigger and the valve gets shrouded and does not flow as well.

My Brian Tooley hand finished TEA LS6 Stage 2.5 from 2003 could flow about 345 cfm (2.08 valve) on a 4.125 bore, 335 on a 4.0 bore and 320 (2.04 valve) 3.9 bore.
Why give up 25 cfm of air flow and potentially 45 to 60 hp by using a 3.9 bore?

I'm sure TEA's newer heads are even better nearly 15 years later.

I went with a 3.9 bore LS1 383 with the TEA's mentioned above and a small cam for my street driven 91 RS Camaro but if the RS was going to be a RACE care only a 4.125 bore block or bigger would have been acceptable to me for the above reasons.

Best wishes on the build.
I would agree with you on some of that because I've seen some less than stellar 383's on this site making less than many 347's. But, Iv'e rolled 510 and 517rwhp with 443 ftlbs on the dyno with my 383 combo and trapped 127mph at 3216lbs. (with me) through a 92mm TB. on pump 91, so they (383's) are not all dead players.
Old 03-04-2017, 10:29 AM
  #16  
TECH Fanatic
iTrader: (5)
 
64post's Avatar
 
Join Date: Nov 2011
Location: Sonoma Co. Ca.
Posts: 1,693
Received 226 Likes on 179 Posts

Default

Originally Posted by MrGame
I actually found a great deal on an LS2 block so looks like it's no longer a problem. I'm going to bore and stroke it out to 408 with some proper heads, a matching cam and a Super Vic intake. Should run well (I hope)
Really? You can bore an LS2 block .030 over?
Old 03-04-2017, 01:16 PM
  #17  
Staging Lane
 
stonebreaker's Avatar
 
Join Date: Dec 2004
Location: Weatherford, TX
Posts: 65
Received 10 Likes on 9 Posts

Default

Originally Posted by redtan
This exactly makes the point everyone has been trying to say. Bore size is very important to heads, and by your example a big bore/displacement can make power even with shitty heads. But a small bore/displacement with big $$$ heads will not make the same power.
You're right - those olde skool heads on a 4.125" bore at 600 hp are making 1.3 hp per cubic inch, while a set of ported cathedrals on a crappy 3.9 inch bore at 500 hp are making 1.4 hp per cubic inch. Just turrable. Even worse, the LS1 weighs 300 lbs less than the big block. Holy cow, what a piece of crap.
Old 03-04-2017, 04:02 PM
  #18  
TECH Addict
iTrader: (15)
 
Mercier's Avatar
 
Join Date: Jun 2014
Location: Baton Rouge, LA
Posts: 2,384
Likes: 0
Received 5 Likes on 5 Posts
Default

Originally Posted by 64post
Really? You can bore an LS2 block .030 over?
Everything I've seen says this is the safe number. Some go less if they are going to boost it to the moon but 4.030" seems pretty common on LS2 blocks. Probably opens up the breathing a little bit for a later model head as well.
Old 03-04-2017, 04:46 PM
  #19  
ModSquad
iTrader: (6)
 
Che70velle's Avatar
 
Join Date: Jan 2012
Location: Dawsonville Ga.
Posts: 6,556
Received 3,622 Likes on 2,218 Posts

Default

Originally Posted by Mercier
Everything I've seen says this is the safe number. Some go less if they are going to boost it to the moon but 4.030" seems pretty common on LS2 blocks. Probably opens up the breathing a little bit for a later model head as well.
Yes, lots of .030" LS2 blocks out there. I went .010" just to de-stress my block after a sleeve replacement, but .030" is possible. I wouldn't go that far if I ever thought of using power adders later on stock sleeves.
I have another LS2 block at RED right now, and it's going out to 4.155", with Darton sleeves of course.



Quick Reply: Is Gen III hardware that bad?



All times are GMT -5. The time now is 05:34 PM.