"Cathedral" or Rectangular" Cylinder Heads ?
Thread Starter
TECH Enthusiast
Joined: Apr 2010
Posts: 651
Likes: 10
From: North Carolina
I told you in my first reply to this thread, flow #'s don't mean everything. Both heads work, and have their places.
For your "particular application" as far as DD worthy street car. I still stick by suggesting cathedral port heads. But thats just me. They have a nice power band. I realllllllllly don't think you can go "wrong" with either one. This subject has been beaten to death over the past few years. Tons of threads pertaining to velocity, port size/shape, valve size, CC design, valve shrouding, blah blah. I'd just buy what fits your budget. Doesn't seem like your number hunting or building a strip car so I think you'll be happy whatever you pick. Just get the right cam.
---On a side-note. TFS does have their new LS3 rect port offering that flows surprisingly well. I was quite tempted to pick up a set of those.
For your "particular application" as far as DD worthy street car. I still stick by suggesting cathedral port heads. But thats just me. They have a nice power band. I realllllllllly don't think you can go "wrong" with either one. This subject has been beaten to death over the past few years. Tons of threads pertaining to velocity, port size/shape, valve size, CC design, valve shrouding, blah blah. I'd just buy what fits your budget. Doesn't seem like your number hunting or building a strip car so I think you'll be happy whatever you pick. Just get the right cam.
---On a side-note. TFS does have their new LS3 rect port offering that flows surprisingly well. I was quite tempted to pick up a set of those.
(1) SDPC CNC LS2 Heads:
Head Flow Numbers:
Lift Intake Flow Exhaust Flow
.200" 147 cfm 115 cfm
.300" 204 cfm 148 cfm
.400" 251 cfm 189 cfm
.500" 289 cfm 200 cfm
.600" 307 cfm 220 cfm
https://sdparts.com/details/scoggin-...er/x88958765-2
************************************************** *******
(2) SDPC LS3 Heads:
Head Flow Numbers:
Lift Intake Flow Exhaust Flow
.200" 151 cfm 111 cfm
.300" 208 cfm 152 cfm
.400" 256 cfm 174 cfm
.500" 294 cfm 183 cfm
.600" 316 cfm 189 cfm
.650" 318 cfm 192 cfm
https://sdparts.com/details/gm-facto...parts/12629063
************************************************** *******
(3) SDPC CNC LS3 Heads:
Head Flow Numbers:
Lift Intake Flow Exhaust Flow
.200" 153 cfm 118 cfm
.300" 225 cfm 180 cfm
.400" 280 cfm 201 cfm
.500" 324 cfm 217 cfm
.600" 350 cfm 230 cfm
.650" 358 cfm 236 cfm
https://sdparts.com/details/scoggin-...enter/sd5881-1
************************************************** *******
I believe that these 3 cylinder heads are the best candidates for my project, based on desired performance, "bang for the buck", and my overall budget.
Thoughts and comments are welcome for everyone . . . Thanks !
Last edited by ez2cdave; Feb 14, 2014 at 02:45 PM.
Banned
Joined: Mar 2013
Posts: 1,137
Likes: 2
From: Studewood/Acres-Homes TX.
SDPC cnc port is 279 cc really big 4 a 408-416ci motor
AI/WCCH 267 cc flows the same. trust me i read your post & these port programs are programed in my head never even looked them up.
AI/WCCH 267 cc flows the same. trust me i read your post & these port programs are programed in my head never even looked them up.
Staging Lane
Joined: Jul 2009
Posts: 85
Likes: 0
I don't want to pry, but how much are you willing to spend on an intake? Budget is playing a huge factor in heads, and it should also on the intake side. They run hand in hand.
408 Results PT 2
^^Copied link from another poster in this thread in case you missed it.
Personally, I don't know if I would go all forged. Your not spraying or planning on boost or a lot of compression. I would consider staying stock stroke, and using the extra money you were going to spend on a forged crank, and add it to your cylinder head budget. Or move up to the LS3 block, stock stroke, forged rods/pistons, and better utilize the LS3 heads you want to run. Saves money on heads/intake, gives you a better bore and unshrouds the valves better on the LS3 heads, and you can acquire LS3 intake manifolds fairly cheap. There's guys just cam swapping LS3's and easily making the power your trying to make.
But I totally understand the want for a stroker, they are a hell of a lot of fun on the street lol. Will get back with you later tonight after I get off work!
408 Results PT 2
^^Copied link from another poster in this thread in case you missed it.
Personally, I don't know if I would go all forged. Your not spraying or planning on boost or a lot of compression. I would consider staying stock stroke, and using the extra money you were going to spend on a forged crank, and add it to your cylinder head budget. Or move up to the LS3 block, stock stroke, forged rods/pistons, and better utilize the LS3 heads you want to run. Saves money on heads/intake, gives you a better bore and unshrouds the valves better on the LS3 heads, and you can acquire LS3 intake manifolds fairly cheap. There's guys just cam swapping LS3's and easily making the power your trying to make.
But I totally understand the want for a stroker, they are a hell of a lot of fun on the street lol. Will get back with you later tonight after I get off work!
Banned
Joined: Mar 2013
Posts: 1,137
Likes: 2
From: Studewood/Acres-Homes TX.
if you want top end Vic Jr. or ported stock ls3 intake bottom end TQ.Just waiting 4 SUPER VIC for ls3 $ 450 vs MAST 1799.oo EFI+ tax i can always port it with the left over 1200bucks. The fast ls3 is junk not the ls7 intake. YOUR HEADS R ONLY AS GOOD AS YOUR INTAKE THE AIR COMES THRU WHAT 1st before it get 2 the heads
CALL HKE / VENGENCE
OR HELL PM ME I GOT THE # U WANT AND WHEN YOUR DONE CALL ANY MAJOR LSX ENGINE BUILDER WITH THE INFO I WILL GIVE U......FACT... THEY WILL TELL YOUR ON THE MARK.
CALL HKE / VENGENCE
OR HELL PM ME I GOT THE # U WANT AND WHEN YOUR DONE CALL ANY MAJOR LSX ENGINE BUILDER WITH THE INFO I WILL GIVE U......FACT... THEY WILL TELL YOUR ON THE MARK.
Last edited by lil john; Feb 14, 2014 at 01:11 PM.
Staging Lane
Joined: Jul 2009
Posts: 85
Likes: 0
Hes not looking for top end, which is why I suggested the LS3 manifold. He wants a "sleeper" street car.
Banned
Joined: Mar 2013
Posts: 1,137
Likes: 2
From: Studewood/Acres-Homes TX.
Main ? is what R YOU WILLING TO SPEND ON HEADS. AFTER THAT IT'S DOWN HILL. 450-480 RWHP SIMPLE.
408 -416
COMP 11+
235-241 intake dur. cam
ported l92-AI/WCCH ........ or.... AFR/TFS YOUR CHOICE
GM LIFTERS AND ROCKERS-REDONE
GOOD HEADERS 1 7/8
GOOD TUNE
STALL TO MATCH CAM
ported ls3 intake
if u have man. trans it is even MORE SIMPLE...
408 -416
COMP 11+
235-241 intake dur. cam
ported l92-AI/WCCH ........ or.... AFR/TFS YOUR CHOICE
GM LIFTERS AND ROCKERS-REDONE
GOOD HEADERS 1 7/8
GOOD TUNE
STALL TO MATCH CAM
ported ls3 intake
if u have man. trans it is even MORE SIMPLE...
Last edited by lil john; Feb 14, 2014 at 01:25 PM.
Staging Lane
Joined: Jul 2009
Posts: 85
Likes: 0
Ez2cDave. I almost forgot. Kind of a good example. I just got done with a 6.0 build for my dads 2nd Gen Camaro cruiser. Stock stroke, stock gen 4 rods, wiseco pistons Should net 368 cubes. He wanted a car he could DD, crisp throttle, fat torque curve. Mamo CNCd a set of 317s for me that outflow most aftermarket 225cc heads, while using a smaller intake valve. Real baby cam for what I'm use to. Right around 11:1 CR. Should clear 430 rwhp pretty easily with a lot of torque.
Last edited by SinisterWS6; Feb 14, 2014 at 01:33 PM.
Thread Starter
TECH Enthusiast
Joined: Apr 2010
Posts: 651
Likes: 10
From: North Carolina
If I go Rectangular Port heads, I'll either use the stock LS3 intake or send it out to be ported, with a 90mm - 92mm Throttle Body.
There is about about a $400-$500 difference between them ( Typhoon is more ), unless I go LS3 and send out the intake to be ported . . . Then, it's a "wash" on cost.
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Verdad Gallardo Thread Starter
TECH Enthusiast
Joined: Apr 2010
Posts: 651
Likes: 10
From: North Carolina
Main ? is what R YOU WILLING TO SPEND ON HEADS. AFTER THAT IT'S DOWN HILL. 450-480 RWHP SIMPLE.
408 -416
COMP 11+
235-241 intake dur. cam
ported l92-AI/WCCH ........ or.... AFR/TFS YOUR CHOICE
GM LIFTERS AND ROCKERS-REDONE
GOOD HEADERS 1 7/8
GOOD TUNE
STALL TO MATCH CAM
ported ls3 intake
if u have man. trans it is even MORE SIMPLE...
408 -416
COMP 11+
235-241 intake dur. cam
ported l92-AI/WCCH ........ or.... AFR/TFS YOUR CHOICE
GM LIFTERS AND ROCKERS-REDONE
GOOD HEADERS 1 7/8
GOOD TUNE
STALL TO MATCH CAM
ported ls3 intake
if u have man. trans it is even MORE SIMPLE...
https://sdparts.com/details/scoggin-...er/x88958765-2
https://sdparts.com/details/gm-facto...parts/12629063
https://sdparts.com/details/scoggin-...enter/sd5881-1
It will be an AUTOMATIC transmission, 4L60E to start out, but I would like to do a 4L80E, when funds permit. Also, a Lock-Up torque converter will be used and MPG is a big factor. This is a TRUE "Daily-Driver" (AVG, 40-50 miles a day, every day ).
I want the quietest exhaust I can get away with. I don't want every "BARNEY" in NC "eyeballing me" unnecessarily !
Another problem . . . The Car must pass North Carolina OBD-II Emissions . . . So, that cam timing would likely need to be re-thought.
Last edited by ez2cdave; Feb 14, 2014 at 06:12 PM.
Thread Starter
TECH Enthusiast
Joined: Apr 2010
Posts: 651
Likes: 10
From: North Carolina
http://www.professional-products.com...atin-p220.html
http://www.professional-products.com...shed-p381.html
I'm not a fan of "plastic" engine parts, especially when they're expensive !
Last edited by ez2cdave; Feb 15, 2014 at 12:19 AM.
Banned
Joined: Mar 2013
Posts: 1,137
Likes: 2
From: Studewood/Acres-Homes TX.
I went 2 there site and IMO. the cnc ls2 would work out best.Call Mars@ Tick for cam.Ported LS3 heads have a port that is REALLY BIG 279cc & the non ported version has a 260cc runner and it don't flow as well as the smaller port cnc ls2.
Teching In
Joined: Mar 2010
Posts: 46
Likes: 0
From: Pensacola, FL
I'm going to leave this right here since everyone is comparing flow numbers but keep in mind that the biggest restriction is all the air you are going to get out of an engine. LS3 intake at BEST will flow between 310-315 cfm's. This is the port work that Rick did and it costs far less than buying a set of $2,000 recast heads. He concentrates on mid lift flow since the valve spends more time there than it does at peak lift. It's like a dyno queen car, it hits a high number and everyone salivates and wants the same build but they forget about all the other information. Smaller cams on LS3/L76 heads are a much better option. I am running a 223/232 .625/.600 on a 112 +0 and I'm almost in the 10's with a 2 ton sedan with these heads.
Stock as shipped:
Intake
.100- 65.5
.200- 149.6
.300- 208.0
.400- 258.0
.500- 297.5
.600- 325.6
.700- 333.6
ported:
.100- 69.9
.200- 153.4
.300- 223.3
.400- 273.3
.500- 313.5
.600- 336.2
.700- 345.4
Exhaust- flowed w/pipe
stock
.100- 58.0
.200- 124.4
.300- 171.1
.400- 202.8
.500- 221.8
.600- 231.9
.700- 237.8
ported w/ radiused valve seats
.100- 59.0
.200- 126.0
.300- 183.3
.400- 231.1
.500- 253.7
.600- 263.2
.700- 271.7
Stock as shipped:
Intake
.100- 65.5
.200- 149.6
.300- 208.0
.400- 258.0
.500- 297.5
.600- 325.6
.700- 333.6
ported:
.100- 69.9
.200- 153.4
.300- 223.3
.400- 273.3
.500- 313.5
.600- 336.2
.700- 345.4
Exhaust- flowed w/pipe
stock
.100- 58.0
.200- 124.4
.300- 171.1
.400- 202.8
.500- 221.8
.600- 231.9
.700- 237.8
ported w/ radiused valve seats
.100- 59.0
.200- 126.0
.300- 183.3
.400- 231.1
.500- 253.7
.600- 263.2
.700- 271.7
Last edited by rocket69GTP; Feb 15, 2014 at 12:51 PM.
Thread Starter
TECH Enthusiast
Joined: Apr 2010
Posts: 651
Likes: 10
From: North Carolina
Thanks for doing some "legwork" for me !
I really like the LS3 heads but, if the CNC'd 799's would work better for my combination, then those will be the ones I use.
Thanks !
Dave
Last edited by ez2cdave; Feb 15, 2014 at 02:10 PM.
Thread Starter
TECH Enthusiast
Joined: Apr 2010
Posts: 651
Likes: 10
From: North Carolina
I'm going to leave this right here since everyone is comparing flow numbers but keep in mind that the biggest restriction is all the air you are going to get out of an engine. LS3 intake at BEST will flow between 310-315 cfm's.
Smaller cams on LS3/L76 heads are a much better option. I am running a 223/232 .625/.600 on a 112 +0 and I'm almost in the 10's with a 2 ton sedan with these heads.
Smaller cams on LS3/L76 heads are a much better option. I am running a 223/232 .625/.600 on a 112 +0 and I'm almost in the 10's with a 2 ton sedan with these heads.
Unfortunately, for me, that puts me "right back on the fence" about whether to go CNC'd 799's or Stock LS3 heads . . . LOL !
At some point, I'm going to have to chose, but I want to "choose wisely" !
Thanks,
Dave
Staging Lane
Joined: Jul 2009
Posts: 85
Likes: 0
We aren't just comparing flow numbers, we are comparing runner CSA vs flow numbers, valve size, etc, then throwing in intake manifolds. All to equate out to what will work best and fit his budget.
Flow numbers only mean so much, and those #'s aren't that impressive for "ported" LS3 heads with what I can only imagine is the runner size. I'd rather see a dyno sheet, time slip from the strip, etc. Just because an intake will only flow so much air only puts a damper on power way past what he is trying to make. Guys with Cam only swap LS3's with un-ported stock intakes are making power higher than what he wants.
So whats the over-all cost of those ported LS3 heads? Buying head castings, shipping, porting, return shipping, etc? Got a runner port size so we can compare? Re-use stock valves? Need valve spring upgrade still to run a camshaft to properly use the flow of those heads? You're leaving a lot of information in the dark and just posting flow.
Dave there is a large amount of "combinations" that can be had to easily make the power you want and be very DD worthy. I think your making this way too complicated for the application man.
Flow numbers only mean so much, and those #'s aren't that impressive for "ported" LS3 heads with what I can only imagine is the runner size. I'd rather see a dyno sheet, time slip from the strip, etc. Just because an intake will only flow so much air only puts a damper on power way past what he is trying to make. Guys with Cam only swap LS3's with un-ported stock intakes are making power higher than what he wants.
So whats the over-all cost of those ported LS3 heads? Buying head castings, shipping, porting, return shipping, etc? Got a runner port size so we can compare? Re-use stock valves? Need valve spring upgrade still to run a camshaft to properly use the flow of those heads? You're leaving a lot of information in the dark and just posting flow.
Dave there is a large amount of "combinations" that can be had to easily make the power you want and be very DD worthy. I think your making this way too complicated for the application man.
Banned
Joined: Mar 2013
Posts: 1,137
Likes: 2
From: Studewood/Acres-Homes TX.
Very correct any 1 of these will make for a good DD 450/480rwhp it all comes down 2 which you like better.There are 2 many LS2/3 head ...stock or stroker combos.Go to Hot ROD article with the 408 and Cat style head... just use a smaller cam.
Thread Starter
TECH Enthusiast
Joined: Apr 2010
Posts: 651
Likes: 10
From: North Carolina
We aren't just comparing flow numbers, we are comparing runner CSA vs flow numbers, valve size, etc, then throwing in intake manifolds. All to equate out to what will work best and fit his budget.
Flow numbers only mean so much, and those #'s aren't that impressive for "ported" LS3 heads with what I can only imagine is the runner size. I'd rather see a dyno sheet, time slip from the strip, etc. Just because an intake will only flow so much air only puts a damper on power way past what he is trying to make. Guys with Cam only swap LS3's with un-ported stock intakes are making power higher than what he wants.
So whats the over-all cost of those ported LS3 heads? Buying head castings, shipping, porting, return shipping, etc? Got a runner port size so we can compare? Re-use stock valves? Need valve spring upgrade still to run a camshaft to properly use the flow of those heads? You're leaving a lot of information in the dark and just posting flow.
Dave there is a large amount of "combinations" that can be had to easily make the power you want and be very DD worthy. I think your making this way too complicated for the application man.
Flow numbers only mean so much, and those #'s aren't that impressive for "ported" LS3 heads with what I can only imagine is the runner size. I'd rather see a dyno sheet, time slip from the strip, etc. Just because an intake will only flow so much air only puts a damper on power way past what he is trying to make. Guys with Cam only swap LS3's with un-ported stock intakes are making power higher than what he wants.
So whats the over-all cost of those ported LS3 heads? Buying head castings, shipping, porting, return shipping, etc? Got a runner port size so we can compare? Re-use stock valves? Need valve spring upgrade still to run a camshaft to properly use the flow of those heads? You're leaving a lot of information in the dark and just posting flow.
Dave there is a large amount of "combinations" that can be had to easily make the power you want and be very DD worthy. I think your making this way too complicated for the application man.
Also, the LS3 heads might be better on a larger bore than what my 4.030" would be. The last thing I want is sluggish response.
Just for the "sake of argument", let me post up a hypothetical setup and see if the "numbers" work for my application.
408 LQ9 Stroker
4.030" Bore
4.000" Stroke
CNC'd 799 heads - 2.00" / 1.55" Valves , 64cc Chamber
PISTONS: What pistons are available to make 11:1 - 11.5:1 with that combination ? Flat-Tops ( probably too high CR ) ? "Dished" pistons ( More prone to Detonation ? ) . . . Other ???
Camshaft profile to give me a DCR or 8.25:1 - 8.5:1 ???
Getting the proper compression ratio and avoiding detonation is critical.
Thanks, in advance, for your input !
Teching In
Joined: Sep 2009
Posts: 28
Likes: 0
From: Sydney, Australia
I'm going to leave this right here since everyone is comparing flow numbers but keep in mind that the biggest restriction is all the air you are going to get out of an engine. LS3 intake at BEST will flow between 310-315 cfm's. This is the port work that Rick did and it costs far less than buying a set of $2,000 recast heads. He concentrates on mid lift flow since the valve spends more time there than it does at peak lift. It's like a dyno queen car, it hits a high number and everyone salivates and wants the same build but they forget about all the other information. Smaller cams on LS3/L76 heads are a much better option. I am running a 223/232 .625/.600 on a 112 +0 and I'm almost in the 10's with a 2 ton sedan with these heads.
Stock as shipped:
Intake
.100- 65.5
.200- 149.6
.300- 208.0
.400- 258.0
.500- 297.5
.600- 325.6
.700- 333.6
ported:
.100- 69.9
.200- 153.4
.300- 223.3
.400- 273.3
.500- 313.5
.600- 336.2
.700- 345.4
Exhaust- flowed w/pipe
stock
.100- 58.0
.200- 124.4
.300- 171.1
.400- 202.8
.500- 221.8
.600- 231.9
.700- 237.8
ported w/ radiused valve seats
.100- 59.0
.200- 126.0
.300- 183.3
.400- 231.1
.500- 253.7
.600- 263.2
.700- 271.7
Stock as shipped:
Intake
.100- 65.5
.200- 149.6
.300- 208.0
.400- 258.0
.500- 297.5
.600- 325.6
.700- 333.6
ported:
.100- 69.9
.200- 153.4
.300- 223.3
.400- 273.3
.500- 313.5
.600- 336.2
.700- 345.4
Exhaust- flowed w/pipe
stock
.100- 58.0
.200- 124.4
.300- 171.1
.400- 202.8
.500- 221.8
.600- 231.9
.700- 237.8
ported w/ radiused valve seats
.100- 59.0
.200- 126.0
.300- 183.3
.400- 231.1
.500- 253.7
.600- 263.2
.700- 271.7
My Pro Comp LS3 heads flow:
0.100 068.7
0.200 137.4
0.300 214.1
0.400 267.3
0.500 304.4
0.600 335.2
0.650 344.9
0.700 354.6
I am again looking at the debate in this thread - Cathederal vs Rectangle - so I am very curious as to the details of your rig rocket69GTP.
