ez2cdave

OK . . . Based on an all-forged LQ9 408 ( 4.030" x 4.000" . . . 11:1 +/- ), I am looking at these heads . . . Thoughts on each, please ?

(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

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(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

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(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

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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 !

lil john

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.

SinisterWS6

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!

lil john

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.

SinisterWS6

Hes not looking for top end, which is why I suggested the LS3 manifold. He wants a "sleeper" street car.

lil john

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...

SinisterWS6

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.

ez2cdave

If I go with Cathedral Port heads, I want the Professional Products LS2 96mm "TYPHOON" - Satin finish along with their 96mm Throttle Body. (Comes with the Fuel Rails ).

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.

ez2cdave

See my post above about head choices and budget . . .

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.

SinisterWS6

I don't think he read much of your thread before posting lol. Just give any of the cam guys like Pat G or Martin a shout and they'll get you sorted out.
Why do you want the prof products intake? Just curious.

ez2cdave

I like the fact that it's an aluminum intake ( durability ) and that the F.A.S.T. intakes aren't worth the money for just a few extra HP, at least in my application. The LS3 intake is a 90mm or 92mm Throttle Body and the Professional Products LS2 Typhoon uses a 96mm Throttle Body that can be enlarged to 101mm.

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 !

lil john

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.

rocket69GTP

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

ez2cdave

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

ez2cdave

Point well taken . . .

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

SinisterWS6

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.

lil john

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.

ez2cdave

My "instinct" is telling me that the SDPC CNC'd 799's would do the job for me, as well as allowing me to use the Professional Products TYPHOON LS2 Intake with their 96mm Throttle Body.

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 !

ez2cdave

No "takers" ???

aussie-revhead

Sorry to butt in but have you got more details on your car? I would be happy as could be to run a 10 with my sedan.

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.