LS3 heads or not???
09-22-2013, 07:53 AM
#1
LS3 heads or not??? Hey guys I have a set of LS3 heads that I was thinking of putting on my LQ4. It has 243s on it now with a custom cam from EPS 230/242 109+3 .600/.615 +18 degrees. 3000-6500+ and it drives damn good.. NO complaints at all...But I was wondering if I put these LS3 heads on with this cam how do you think it would do vs what I already have?
Also wondering if I should milled them and if so how much so I wouldn't have to deal with PTV issues? My pistons are already flycut from the factory (Ironically they are)...
Also wondering if I should milled them and if so how much so I wouldn't have to deal with PTV issues? My pistons are already flycut from the factory (Ironically they are)...
09-22-2013, 12:11 PM
#2
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I'm not a cam genius but I can tell you even if your pistons were flycut from the factory, they probably weren't fly cut for the big ls3 intake valve. The only way to know if the cam will fit for sure with plenty of room is to measure. Trust me, you don't want that intake valve contacting your piston at any rpm, it's not a solid stem.
09-22-2013, 02:52 PM
#4
Hey guys I have a set of LS3 heads that I was thinking of putting on my LQ4. It has 243s on it now with a custom cam from EPS 230/242 109+3 .600/.615 +18 degrees. 3000-6500+ and it drives damn good.. NO complaints at all...But I was wondering if I put these LS3 heads on with this cam how do you think it would do vs what I already have?
Also wondering if I should milled them and if so how much so I wouldn't have to deal with PTV issues? My pistons are already flycut from the factory (Ironically they are)...
Also wondering if I should milled them and if so how much so I wouldn't have to deal with PTV issues? My pistons are already flycut from the factory (Ironically they are)...
09-22-2013, 08:35 PM
#6
I am thinking he can get $400 for the 243s and maybe another $400 for the LS3s? He would have $800. Then he would only be $400 away from some CNC PRC LS6 heads. He can then run more camshaft without fly-cutting, have more compression and likely have superior performance over the LS3s on a 4" bore motor.
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09-23-2013, 02:11 AM
#9
ok guys sorry my phone was typing crazy and I was driving...So here's the dilemma, My 243 I had on my 6.0, I swapped them with a buddy of mine for his LS3 heads....I've been reading and researching etc LQ4 with LS3 heads with 23x/24x .620/.630 110 LSA where ppl haven't been flycutting...DOESNT MEAN I WONT BE CHECKING FOR MYSELF...Im not looking for an all out racer just a lil more than what I had...Think Im getting greedy!!! Sorry my pistons have valve reliefs for stock 317s....(same as flycut maybe, idk)
09-23-2013, 04:52 AM
#11
10 Second Club
As stated elsewhere ....LS3 heads like to breath, need a cam and rpm. (or cubic inches)
Ported heads may be better suited to your combo, depending on intended use.
Ported heads may be better suited to your combo, depending on intended use.
09-23-2013, 08:43 AM
#12
What doug G said, Now that I think about it, on my car from 2k-3800rpm, (in a 408) car is a turd compared to about 4k-4500 to about 7500 rpm it rips your neck off. It accelerates faster and faster the more rpm you throw at it. I'm just too scared to go past 7200 consistently. Don't get me wrong, the car has great torque down low and will lug any gear at just about any rpm, But just does not come on intense until 4k and on.
09-23-2013, 08:45 AM
#13
to the op, I have a cam very similar to yours, (eps, originally designed it for me for a stock cube build) and I had enough ptc to run it, Closer than I wanted but what most would say acceptable. But I would check any way as you stated.
09-23-2013, 10:35 AM
#14
@Zone, thanks buddy I'v sold my rpm intake now trying to decide on which intake for the LS3s.....The Vic Jr or the GMPP Dual plane...already had intake rockers for them..
@Doug, thanks for the insight sir...My intended use of the car KILL STANGS, and maybe drive it once or twice a month....Nothing more!!
@Stevecrit...Don't scare me like that....there's no turning back now, lol...I wonder if your definition of a turd is different than mine (car related turd)....So you never milled your head? and yours are P&P...im not going that far with these...Not trying to go that fast!!!! Just enough to play with the guys here in my town.
@Doug, thanks for the insight sir...My intended use of the car KILL STANGS, and maybe drive it once or twice a month....Nothing more!!
@Stevecrit...Don't scare me like that....there's no turning back now, lol...I wonder if your definition of a turd is different than mine (car related turd)....So you never milled your head? and yours are P&P...im not going that far with these...Not trying to go that fast!!!! Just enough to play with the guys here in my town.
09-23-2013, 11:34 AM
#15
Ok I just got off the phone with Geoff, he stated that with my cam I shouldn't run into any PTV clearances with the LS3 heads on my LQ4....BUT he said that he would calculate the numbers for me but said that he's positive that I wouldn't run into any problems! I didn't post my setup on here but here goes. If you need anymore info let me know.
Stock 50k mile 2005 LQ4 w/stock valve reliefs
Custom EPS cam 230/242 @.050 .600/.615 109+3
LS3 heads UNMILLED at this moment
some juice later on
Pacesetter Long Tubes
QuickFuel 780
Dual Plane or Vic Jr intake...Undecided!!!
Revmax 3600 stall
700r4
True Duals, Xpipe, new Borla ProXs..
))
3.42 gears
8.5 rear
car weight is 3880
Stock 50k mile 2005 LQ4 w/stock valve reliefs
Custom EPS cam 230/242 @.050 .600/.615 109+3
LS3 heads UNMILLED at this moment
some juice later on
Pacesetter Long Tubes
QuickFuel 780
Dual Plane or Vic Jr intake...Undecided!!!
Revmax 3600 stall
700r4
True Duals, Xpipe, new Borla ProXs..
))3.42 gears
8.5 rear
car weight is 3880
09-23-2013, 12:01 PM
#16
You are changing your entire power curve. The cam will now "act" bigger because of the increased runner size and flow on the intake side. Everything will need adjusted especially the rear gearing. The space in the 1-2 gearing of the 700r4 will be much more obvious. (TH350 time). I would have put a victor on it, 3.73 gears in it and a 150 shot and called it a day IMO.
Last edited by The stunningman; 09-23-2013 at 12:11 PM.
09-23-2013, 12:22 PM
#17
I guess that's a hindsight thing ATM (just read back through the thread).
Carb needs to go up to 850-950 minimum
Sell the 700r4 and converter and get a TH350 with a stall spec'd around 4200 on the bottle. You should GAIN $$ in this deal.
Change the gearing to get the most out of the highest RPM's you feel comfortable with in the distance you will be racing.
Victor JR. You have the heads that are going to flow...work around that. GMPP single plain is 1" shorter measure to see what clears in the allotted space with a decent air cleaner and keep in mind the 1/2" spacer for the shot.
Carb needs to go up to 850-950 minimum
Sell the 700r4 and converter and get a TH350 with a stall spec'd around 4200 on the bottle. You should GAIN $$ in this deal.
Change the gearing to get the most out of the highest RPM's you feel comfortable with in the distance you will be racing.
Victor JR. You have the heads that are going to flow...work around that. GMPP single plain is 1" shorter measure to see what clears in the allotted space with a decent air cleaner and keep in mind the 1/2" spacer for the shot.
09-23-2013, 12:59 PM
#18
It's up to you, but I think that combo would run really well with the GMPP dual plane.
You don't hear much about the LS3 dual plane intake because so few have run it on this forum. It is expensive and there aren't many who will make the leap into the unknown. Take my word (and pictures), the LS3 dual plane is nothing like the tiny cathedral performer RPM intake. https://ls1tech.com/forums/carburete...-included.html
The runners are huge on the LS3 dual plane intake and basically maintain the same rectangle port cross section throughout the length of the runner from the plenum to the head. The inherent advantages of the dual plane intake will bolster the low and mid rpm range and I doubt it would really give up that much upper RPM horsepower to the Victor JR.
Andy at D&A Machine did some back to back testing using the GMPP Single Plane and the GMPP dual plane for their destroked 6.0 based 334", Ls3 head, Engine Masters Competition engine.
The single plane never matched the dual plane at any test point.
(They went on to make 540HP with the dual plane intake on this small engine after a swap to a 232/240 108+5 solid roller cam.)
https://ls1tech.com/forums/carburete...e-intakes.html post#15
You don't hear much about the LS3 dual plane intake because so few have run it on this forum. It is expensive and there aren't many who will make the leap into the unknown. Take my word (and pictures), the LS3 dual plane is nothing like the tiny cathedral performer RPM intake. https://ls1tech.com/forums/carburete...-included.html
The runners are huge on the LS3 dual plane intake and basically maintain the same rectangle port cross section throughout the length of the runner from the plenum to the head. The inherent advantages of the dual plane intake will bolster the low and mid rpm range and I doubt it would really give up that much upper RPM horsepower to the Victor JR.
Andy at D&A Machine did some back to back testing using the GMPP Single Plane and the GMPP dual plane for their destroked 6.0 based 334", Ls3 head, Engine Masters Competition engine.
The single plane never matched the dual plane at any test point.
(They went on to make 540HP with the dual plane intake on this small engine after a swap to a 232/240 108+5 solid roller cam.)
https://ls1tech.com/forums/carburete...e-intakes.html post#15
Ok guys, It took me a while to do it but I finally found some dyno sheets.
Its not the exact ones I wanted but they will have to do since the dyno computer is acting up and we can't find the right ones.
These are from the same day about ten minutes apart.
Test 1 Single Plane.......Test 2 Dual-Plane
3000-[228hp[398tq]......[235hp[412tq]
3200-[249hp[410tq]......[253hp[416tq]
3400-[266hp[411tq]......[269hp[415tq]
3600-[282hp[412tq]......[289hp[422tq]
3800-[307hp[425tq]......[316hp[437tq]
4000-[327hp[430tq]......[332hp[436tq]
4200-[337hp[422tq]......[342hp[428tq]
4400-[355hp[423tq]......[361hp[431tq]
4600-[368hp[421tq]......[372hp[425tq]
4800-[379hp[415tq]......[384hp[420tq]
5000-[402hp[423tq]......[406hp[427tq]
5200-[421hp[425tq]......[432hp[436tq]
5400-[439hp[427tq]......[449hp[437tq]
5600-[455hp[426tq]......[464hp[435tq]
5800-[477hp[432tq]......[480hp[435tq]
6000-[489hp[428tq]......[493hp[431tq]
6200-[493hp[417tq]......[494hp[419tq]
6400-[491hp[403tq]......[492hp[404tq]
This was some of the first pulls on this engine and before we swapped
to a different cam. It is a 334 cube with 11.5 to 1.
Both pulls were with an 830 holley on a 1 inch spacer.
Demos Cam, 224/228 108+6
Andy
Its not the exact ones I wanted but they will have to do since the dyno computer is acting up and we can't find the right ones.
These are from the same day about ten minutes apart.
Test 1 Single Plane.......Test 2 Dual-Plane
3000-[228hp[398tq]......[235hp[412tq]
3200-[249hp[410tq]......[253hp[416tq]
3400-[266hp[411tq]......[269hp[415tq]
3600-[282hp[412tq]......[289hp[422tq]
3800-[307hp[425tq]......[316hp[437tq]
4000-[327hp[430tq]......[332hp[436tq]
4200-[337hp[422tq]......[342hp[428tq]
4400-[355hp[423tq]......[361hp[431tq]
4600-[368hp[421tq]......[372hp[425tq]
4800-[379hp[415tq]......[384hp[420tq]
5000-[402hp[423tq]......[406hp[427tq]
5200-[421hp[425tq]......[432hp[436tq]
5400-[439hp[427tq]......[449hp[437tq]
5600-[455hp[426tq]......[464hp[435tq]
5800-[477hp[432tq]......[480hp[435tq]
6000-[489hp[428tq]......[493hp[431tq]
6200-[493hp[417tq]......[494hp[419tq]
6400-[491hp[403tq]......[492hp[404tq]
This was some of the first pulls on this engine and before we swapped
to a different cam. It is a 334 cube with 11.5 to 1.
Both pulls were with an 830 holley on a 1 inch spacer.
Demos Cam, 224/228 108+6
Andy
Last edited by topbrent; 09-23-2013 at 02:29 PM.
09-23-2013, 01:35 PM
#19
Im in that minority of people that stuck the GMPP dual plane on my engine. I like it and think like TopBrent does on the cross section of the intake. It is huge compared to the cat head dual plane. The main thing I see in your combo that makes me say dual plane is the 3880lbs race weight. That low end torque should come in handy moving the car in NA trim.
09-23-2013, 02:30 PM
#20
IMO the nitrous would benefit from the single plane. The dual plane will likely be null if you change the set-up to take advantage of the flow of the heads. I read somewhere in there car is driven minimal and basically wants to kill stangs.
3880 just means a lot more broken parts when trying to go faster.
3880 just means a lot more broken parts when trying to go faster.