rebuilding engine, looking for torque
Thread Starter
Staging Lane
Joined: May 2017
Posts: 52
Likes: 0
From: central ky
rebuilding engine, looking for torque so like the title reads im about to be rebuilding my ls1. I bought the car a few months ago with a ms3 cam already installed but no supporting mods. I installed a edge 3800 stall convertor, then shortly after I lost all oil pressure. drained my oil and its full of metal...so i finally got the motor pulled out and after removing the valley cover I can see my ms3 cam is damaged.
so now that i know im replacing the cam also I think im gonna go a different direction with my build. im looking for the best cam/head package to make low end torque. not really wanting to rev past 6k. I figure for heads the prc stage 2.5 5.3 heads for a bump in compression, but im needing help with cam selection. I prefer a choppy idle but will sacrifice it for more torque. and im not worried about emmisions here.
any info is appreciated
so now that i know im replacing the cam also I think im gonna go a different direction with my build. im looking for the best cam/head package to make low end torque. not really wanting to rev past 6k. I figure for heads the prc stage 2.5 5.3 heads for a bump in compression, but im needing help with cam selection. I prefer a choppy idle but will sacrifice it for more torque. and im not worried about emmisions here.
any info is appreciated
^ right out high lift hotcam sounds pretty mean at idle and makes pretty goo power. stops at 6200-6300 so doesnt rev high. makes good tq. easy on springs. easy to tune and drive.
What else were you looking at replacing?
Idle clip, dyno, and time slips of our cam HERE
What else were you looking at replacing?
Idle clip, dyno, and time slips of our cam HERE
If the cam lost much material I sure hope you plan on a complete rebuild. I've seen way to many people try to get by without doing a complete refresh. The metal from the cam plays hell on bearings and is very hard to get out of all the nooks and crannies without stripping to the bare block and properly cleaning it.
I have built a few SBE LS1's built for torque, that still pulled to 6,200-6,400 rpm. I would look into the PRC Stage 1 or 2.5 243 heads and have them shaved to bump the compression up to 10.5:1-11:1, which will help with the torque curve. 243 Cathedral port heads are, in my opinion, the best OEM heads for a Sub-4.000" bore, especially when using flat top pistons. For a more even hp/tq curve that will pull to 6-6,200 rpm, look at getting some 1-3/4 longtubes. An LS6 intake with a 90mm Throttle body will help with throttle response and gain about 10 rwhp.
-If you can find them, I would look for a good set of 243 heads off a 02-04 C5Z LS6 that still have the stock lightweight valves in them. Then have TSP-PRC do a Stage-1 Port, which will retain the lightweight 2.00"/1.55" Valves, have them milled accordingly to achieve between 10.5-11:1 Static Compression, and use Titanium Retainers on the valve springs to keep the weight down and improve valvetrain harmonics. Which will help prevent Valve Float and gain a few extra ponies.
The WS6Store can get you setup with a complete rebuild kit, if needed, and/or a cam for your needs. I would also look into their New Trunnion kits that come with new GM OEM Rocker arms, which uses a Needle Bearing Style Trunnion (NOT Comp Cams Brand).
I would use a cam with around a .600/.600 lift on a 112 LSA, and some BTR .660 Platinum Dual Springs with Titanium Retainers, or equivalent. Keep the lift under .630 and the open spring pressure under 400 lbs with stock rocker arms. Generally, the more lift, the more power. It can also lower the Hp/Tq Curves down in the rpm range yet still pull past 6k.
-If you can find them, I would look for a good set of 243 heads off a 02-04 C5Z LS6 that still have the stock lightweight valves in them. Then have TSP-PRC do a Stage-1 Port, which will retain the lightweight 2.00"/1.55" Valves, have them milled accordingly to achieve between 10.5-11:1 Static Compression, and use Titanium Retainers on the valve springs to keep the weight down and improve valvetrain harmonics. Which will help prevent Valve Float and gain a few extra ponies.
The WS6Store can get you setup with a complete rebuild kit, if needed, and/or a cam for your needs. I would also look into their New Trunnion kits that come with new GM OEM Rocker arms, which uses a Needle Bearing Style Trunnion (NOT Comp Cams Brand).
I would use a cam with around a .600/.600 lift on a 112 LSA, and some BTR .660 Platinum Dual Springs with Titanium Retainers, or equivalent. Keep the lift under .630 and the open spring pressure under 400 lbs with stock rocker arms. Generally, the more lift, the more power. It can also lower the Hp/Tq Curves down in the rpm range yet still pull past 6k.
Last edited by 07NBSChevy; Jul 27, 2017 at 03:43 AM.
Trending Topics
Thread Starter
Staging Lane
Joined: May 2017
Posts: 52
Likes: 0
From: central ky
im running a 3:73 gear and a 275/40/17 tire.
I do plan on a complete rebuild after seeing the cam, if im this far into the motor im going to do it right.
also I forgot to mention im running hedman long tubes already.
and whatever heads I end up getting I will be investing in brian tooley springs
I do plan on a complete rebuild after seeing the cam, if im this far into the motor im going to do it right.
also I forgot to mention im running hedman long tubes already.
and whatever heads I end up getting I will be investing in brian tooley springs
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo We have everything you need for that at the best price youll find. Right now our rebuild kits are $30 off also.
If you want, shoot me an email and let me know what you are looking at!! (Its alot easier to track)
Rpmspeedtech@gmail.com
If you want, shoot me an email and let me know what you are looking at!! (Its alot easier to track)
Rpmspeedtech@gmail.com
Thread Starter
Staging Lane
Joined: May 2017
Posts: 52
Likes: 0
From: central ky
that hotcam is interesting, anybody else have a cam making nice torque numbers down low?
would the prc stage 2.5 ls6 heads be a better choice than the prc stage 2.5 5.3 heads for what im looking for?
would the prc stage 2.5 ls6 heads be a better choice than the prc stage 2.5 5.3 heads for what im looking for?
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
Those two heads are very similar. By the time both have been ported, they flow VERY similar numbers. The 5.3 heads start with much smaller valves than the LS6, so gain much more to get even with the LS6. If you go to TSP's website and look at these heads you will see what I mean.
Thread Starter
Staging Lane
Joined: May 2017
Posts: 52
Likes: 0
From: central ky
but would the 5.3 do better at bumping compression?
my budget is running thin so im just trying to buy a better set of heads then my stock 853's, im trying not to also pay for porting or milling heads. not at this point anyways.
So maybe the better question is if choosing between the two heads and not porting or milling which would better suit me?
thanks for the advice
my budget is running thin so im just trying to buy a better set of heads then my stock 853's, im trying not to also pay for porting or milling heads. not at this point anyways.
So maybe the better question is if choosing between the two heads and not porting or milling which would better suit me?
thanks for the advice
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
If you want a stock head, go for the 243/799 casting. The 799 is a later version of the 243. Either is a great starting point, and a big flow improvement over the LS1 head. And porting improves either one. The 5.3 head might give a little more compression, but would choke your engine in stock form
I'd pair that cam with a set of AFR205 heads. Those are about the best for torque. Nice long runner intake. Long tube headers.
Now you might need less overlap if you gotta pass a sniffer. If that's the case you'll need something custom and then mill the heads for compression. In general, aim for 8.5-8.7 dynamic compression for great torque and not detonation.
Now you might need less overlap if you gotta pass a sniffer. If that's the case you'll need something custom and then mill the heads for compression. In general, aim for 8.5-8.7 dynamic compression for great torque and not detonation.
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
IF he can get a deal on used AFR205's then yeah. He did mention a thin budget. Used is all he will find, as it was replaced by the AFR210 a while back. If he can source some 799's at the boneyard, he will be ahead of where he is now, I believe.
Originally Posted by G Atsma
IF he can get a deal on used AFR205's then yeah. He did mention a thin budget. Used is all he will find, as it was replaced by the AFR210 a while back. If he can source some 799's at the boneyard, he will be ahead of where he is now, I believe.
That is not completely correct. While the 243 head did come before the 799 head, the 799 is supposedly a rougher cast produced by outsourced vendors. While the 243 heads are a smother cast produced by GM, both using the same mold from GM making the heads identical. You can visual see the difference between the two under close examination such as roughly casting lines and roughly ports on the 799 heads. Nothing noticeable unless looking for it.
243 heads were used on the 2001-2004 Corvette Z06 with the LS6, as well as the 2004-2005 CTS-V with the LS6 engine. Only the 2002-2004 Corvette C5Z (405-Hp Version) got the Stainless Steel Hollow Stem Intake and the Sodium Filled Exhaust Valves, while the LS6 in the CTS-V used standard LS-1 valves.
Some 2005-2007 4.8 and 5.3 (Non L33) Engines reportedly came with 799/243 heads.
All 2005-2007 L33 5.3 Engines used the 799 head, some say they have used the 243 head.
All Gen4 4.8 and 5.3 engines from 2007.5-2013 only used the 799 or 243 heads with standard LS-1 valves.
For the most part, GM favored the Gen4 4.8's to get the 799 heads while the Gen4 5.3's got the 243 heads. Either head has been used on either engine, as well as some engines received 1 head as a 243 while the other is a 799.
243 heads were used on the 2001-2004 Corvette Z06 with the LS6, as well as the 2004-2005 CTS-V with the LS6 engine. Only the 2002-2004 Corvette C5Z (405-Hp Version) got the Stainless Steel Hollow Stem Intake and the Sodium Filled Exhaust Valves, while the LS6 in the CTS-V used standard LS-1 valves.
Some 2005-2007 4.8 and 5.3 (Non L33) Engines reportedly came with 799/243 heads.
All 2005-2007 L33 5.3 Engines used the 799 head, some say they have used the 243 head.
All Gen4 4.8 and 5.3 engines from 2007.5-2013 only used the 799 or 243 heads with standard LS-1 valves.
For the most part, GM favored the Gen4 4.8's to get the 799 heads while the Gen4 5.3's got the 243 heads. Either head has been used on either engine, as well as some engines received 1 head as a 243 while the other is a 799.
^ right out high lift hotcam sounds pretty mean at idle and makes pretty goo power. stops at 6200-6300 so doesnt rev high. makes good tq. easy on springs. easy to tune and drive.
What else were you looking at replacing?
Idle clip, dyno, and time slips of our cam HERE
What else were you looking at replacing?
Idle clip, dyno, and time slips of our cam HERE