Heads and Cam Planning
02-12-2017, 08:37 PM
#1
Advanced
Thread Starter
Heads and Cam Planning
Working with a 2003 A4
So far I have the usual bolt ons.
Intake
ARH 1 7/8 catless
Borla exhaust
I'm looking at doing the following
Comp Cam 224/228 .581/.588 114
Beehive valve spring kit
Comp cam timing set
Rocker arm trunnion upgrade kit
Maybe oil pump not sure yet.
Heads - I'm kind of at a loss. Can I stick with stock or is that just a dumb idea??
I have been looking at a set of heads from texas speed
PRC stage 2.5 LS6 Ported heads.
It says they are seasoned GM 243 or 799 cores - what does that mean?
And offers 58-64cc chambers.
I'm just at loss on what direction to go with the heads.
So far I have the usual bolt ons.
Intake
ARH 1 7/8 catless
Borla exhaust
I'm looking at doing the following
Comp Cam 224/228 .581/.588 114
Beehive valve spring kit
Comp cam timing set
Rocker arm trunnion upgrade kit
Maybe oil pump not sure yet.
Heads - I'm kind of at a loss. Can I stick with stock or is that just a dumb idea??
I have been looking at a set of heads from texas speed
PRC stage 2.5 LS6 Ported heads.
It says they are seasoned GM 243 or 799 cores - what does that mean?
And offers 58-64cc chambers.
I'm just at loss on what direction to go with the heads.
02-13-2017, 02:37 AM
#4
Le Mans Master
Member Since: Aug 2005
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St. Jude Donor '13-'14-'15
A 2003 should already have the LS 6 intake manifold however you still have the basic LS1 heads-- Simply changing to a STOCK set of LS6 heads should add maybe 10-12 RWHP But if you can afford it a set od ported 243 LS6 heads could add another 10-15 RWHP so it depends on your budget----In the past you could find a set of take off LS6 heads 243's for about $700 but those now are hard to find Not only do any LS6 head add airflow they also increase the compression ratio----The larger your cam the more HP and TQ you will make with a set of better flowing heads
PS I would never reccomend to simply port a stock set of LS1 heads-- as you may gain some airflow but the compression ratio is hard to increase and the exhaust ports are way to small to make big HP numbers
PS I would never reccomend to simply port a stock set of LS1 heads-- as you may gain some airflow but the compression ratio is hard to increase and the exhaust ports are way to small to make big HP numbers
02-13-2017, 05:47 AM
#5
Safety Car
Rsharpatx, I like your choices.
The LS6 beehive springs are rated for .570" lift though.
Check your compression ratios. I prefer a bit higher compression on a naturally aspirated engine. With your longer duration cam your dynamic compression will drop due to the intake valve being open a bit more when the piston comes back up. These cams tend to like/need higher static compression to maintain the same dynamic compression.
The 58cc chambers seem too small. I would rather use the 64cc heads with a thinner head gasket (.040" instead of the standard .051") to achieve the higher compression.
The reason for the thinner head gasket instead of smaller chambers is something called quench (air squeezed into the flat surface of the cylinder head). Reducing quench will reduce detonation.
There is no set HP figure for what a specific head swap would yield. It's more of a percentage of gain where other components are factored.
I think your set up would yield 475-500+ FWHP increase torque through the entire RPM range, and have near perfect street manners. I hope you have 3.15 or lower gears. You will probably benefit with a higher stall converter but not necessary.
The LS6 beehive springs are rated for .570" lift though.
Check your compression ratios. I prefer a bit higher compression on a naturally aspirated engine. With your longer duration cam your dynamic compression will drop due to the intake valve being open a bit more when the piston comes back up. These cams tend to like/need higher static compression to maintain the same dynamic compression.
The 58cc chambers seem too small. I would rather use the 64cc heads with a thinner head gasket (.040" instead of the standard .051") to achieve the higher compression.
The reason for the thinner head gasket instead of smaller chambers is something called quench (air squeezed into the flat surface of the cylinder head). Reducing quench will reduce detonation.
There is no set HP figure for what a specific head swap would yield. It's more of a percentage of gain where other components are factored.
I think your set up would yield 475-500+ FWHP increase torque through the entire RPM range, and have near perfect street manners. I hope you have 3.15 or lower gears. You will probably benefit with a higher stall converter but not necessary.
02-13-2017, 07:38 AM
#6
Team Owner
Not sure why the Comp timing set, I would personally go with the Cloyes Hex-Adjust so you can degree the cam. If you go tight on compression, which I would agree with the recommendation from Rob 02, then you should degree the cam and the ability to adjust is very handy. I would also consider a timing chain damper while you are in there. Not sure how much the PRC heads are but I would look at the MMS as cast heads however bronze guides need new rockers. Otherwise, I would look at AI ported heads. They can even do your stock 241 heads with great results.
02-13-2017, 06:53 PM
#7
Melting Slicks
Well, seeing as a stock LS6 makes 385 ish to the wheels(440-450 flywheel) with the basics, you should be able to make upper 400's(470-480) at the flywheel with stock 243/799 heads and a small cam.
Last edited by FASTFATBOY; 02-13-2017 at 06:53 PM.
02-18-2017, 10:59 PM
#9
Burning Brakes
I did a similar project last summer. Not sure what the right answers for you are but here's what I did and why. I have a similar 222/226 600 112 cam and love it. Good power with stock-like driving manors.
My builder suggested just replacing the timing chaining with a LS2 chain and using the stock gears rather than a whole timing set. I think it was only $60 or so.
I did the oil pump since it was apart.
With all the threads about wobbling balancers consider replacing it while it's apart.
I went with a set of ported 243 heads. Much better than the 241s that were on there and much cheaper than some aftermarkets that will make more power but cost significantly more too. Depends on what you want to spend...
Don't get the GM blue springs with that lift. I have a buddy that works for PAC. He steered me to a shot peened single beehive good for 625 lift - the PAC 1219x. And the 1218 is good for 600 lift. The x is the shot peended version for a few more $s. Duals provide insurance but his take was a good single is adequate for a non race application and easier on the valvetrain so that's what I went with.
Mine is an 01 so it has the ls6 intake. When the dust settled I was plus 80hp and 60tq over just a cold air, cat back and a tune - same dyno and same tuner. HP peaks at 6,300 rpm and carries almost flat to the 6,750 rev limit.
Bring this thread back to life after your project is complete so we can hear the results. Good luck!
My builder suggested just replacing the timing chaining with a LS2 chain and using the stock gears rather than a whole timing set. I think it was only $60 or so.
I did the oil pump since it was apart.
With all the threads about wobbling balancers consider replacing it while it's apart.
I went with a set of ported 243 heads. Much better than the 241s that were on there and much cheaper than some aftermarkets that will make more power but cost significantly more too. Depends on what you want to spend...
Don't get the GM blue springs with that lift. I have a buddy that works for PAC. He steered me to a shot peened single beehive good for 625 lift - the PAC 1219x. And the 1218 is good for 600 lift. The x is the shot peended version for a few more $s. Duals provide insurance but his take was a good single is adequate for a non race application and easier on the valvetrain so that's what I went with.
Mine is an 01 so it has the ls6 intake. When the dust settled I was plus 80hp and 60tq over just a cold air, cat back and a tune - same dyno and same tuner. HP peaks at 6,300 rpm and carries almost flat to the 6,750 rev limit.
Bring this thread back to life after your project is complete so we can hear the results. Good luck!
02-19-2017, 07:28 PM
#11
Advanced
Thread Starter
I did a similar project last summer. Not sure what the right answers for you are but here's what I did and why. I have a similar 222/226 600 112 cam and love it. Good power with stock-like driving manors.
My builder suggested just replacing the timing chaining with a LS2 chain and using the stock gears rather than a whole timing set. I think it was only $60 or so.
I did the oil pump since it was apart.
With all the threads about wobbling balancers consider replacing it while it's apart.
I went with a set of ported 243 heads. Much better than the 241s that were on there and much cheaper than some aftermarkets that will make more power but cost significantly more too. Depends on what you want to spend...
Don't get the GM blue springs with that lift. I have a buddy that works for PAC. He steered me to a shot peened single beehive good for 625 lift - the PAC 1219x. And the 1218 is good for 600 lift. The x is the shot peended version for a few more $s. Duals provide insurance but his take was a good single is adequate for a non race application and easier on the valvetrain so that's what I went with.
Mine is an 01 so it has the ls6 intake. When the dust settled I was plus 80hp and 60tq over just a cold air, cat back and a tune - same dyno and same tuner. HP peaks at 6,300 rpm and carries almost flat to the 6,750 rev limit.
Bring this thread back to life after your project is complete so we can hear the results. Good luck!
My builder suggested just replacing the timing chaining with a LS2 chain and using the stock gears rather than a whole timing set. I think it was only $60 or so.
I did the oil pump since it was apart.
With all the threads about wobbling balancers consider replacing it while it's apart.
I went with a set of ported 243 heads. Much better than the 241s that were on there and much cheaper than some aftermarkets that will make more power but cost significantly more too. Depends on what you want to spend...
Don't get the GM blue springs with that lift. I have a buddy that works for PAC. He steered me to a shot peened single beehive good for 625 lift - the PAC 1219x. And the 1218 is good for 600 lift. The x is the shot peended version for a few more $s. Duals provide insurance but his take was a good single is adequate for a non race application and easier on the valvetrain so that's what I went with.
Mine is an 01 so it has the ls6 intake. When the dust settled I was plus 80hp and 60tq over just a cold air, cat back and a tune - same dyno and same tuner. HP peaks at 6,300 rpm and carries almost flat to the 6,750 rev limit.
Bring this thread back to life after your project is complete so we can hear the results. Good luck!
I was looking at the Rocker Arm Trunnion upgrade kit. Is this something that is worth the time and money?
02-19-2017, 08:24 PM
#12
Burning Brakes
I did the trunnions. Did I need to for a car that's street driven and not raced - my guess is no. I felt like I did a lot of reading/researching on the forum last winter when I was planning/selecting cam/heads/headers etc. and I didn't come across lots of threads about the stock rockers failing. But, I figured the rest of the valve train was new so why not. Oh yea, I did the LS7 lifters and new trays too since it was apart. Maybe someone else can chime in on when the trunnion upgrade is a must.