L92 Head/Intake Question
05-26-2009, 09:08 AM
#1
L92 Head/Intake Question I'm thinking about building a 408.
Just wondering how a port set of L92's would work with a big cubed motor.
Also was wondering on the intakes.
How do the LS3 intakes compare to the carb style intake?
Just wondering because I like the look of a carb style intake with an elbow and throttle body.
Just wondering how a port set of L92's would work with a big cubed motor.
Also was wondering on the intakes.
How do the LS3 intakes compare to the carb style intake?
Just wondering because I like the look of a carb style intake with an elbow and throttle body.
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06-06-2009, 04:29 AM
#8
I have a set of mild port L92 and a 242/246 custom cam. stock 07 LY6 crank rods and pistons in a 07 GMPP 6.0L block with ARP rod bolts, heads milled .075" and pistons flycut on the intake side. untouched GMPP intake(milled to fit) edelbrock ultra low elbow and a holley 90MM tb. made 580 on the engine dyno, so prolly 500+ at the wheels. Not to bad for a stock short block.
06-09-2009, 11:36 AM
#9
I have a 408 with the L92 heads and carb style intake. You can see it in my sign and pic. Mine is lacking very bad on the big end. I do not think its doing any better then 400hp at the crank. Car has only turned 12.77 ET at 105mph. I am very disapointed in its performance so far. The heads are ported, cam is a little small I guess (230/240/114), compression is low at 10.25:1. I have been told the Edelbrock Elbow is the problem. I realy do not know. BES Stroked Nova is running the same intake elbow set up as me and he make alot more power then I do. Not sure why.
06-09-2009, 12:24 PM
#10
I have a 408 with the L92 heads and carb style intake. You can see it in my sign and pic. Mine is lacking very bad on the big end. I do not think its doing any better then 400hp at the crank. Car has only turned 12.77 ET at 105mph. I am very disapointed in its performance so far. The heads are ported, cam is a little small I guess (230/240/114), compression is low at 10.25:1. I have been told the Edelbrock Elbow is the problem. I realy do not know. BES Stroked Nova is running the same intake elbow set up as me and he make alot more power then I do. Not sure why.
tune? bump up the compression to 11.5.1 and get a retune
06-09-2009, 12:33 PM
#11
Sorry to have left this out, I do the tuning and I am installing a GT88 turbo on the car. We built the engine for FI. Some other threads on here are pointing to the ultra low profile Edelbrock elbow as killing the power. But I see BES is making the kind of power we expected to make with almost the same set up and less CI's.
06-09-2009, 12:53 PM
#12
Sorry to have left this out, I do the tuning and I am installing a GT88 turbo on the car. We built the engine for FI. Some other threads on here are pointing to the ultra low profile Edelbrock elbow as killing the power. But I see BES is making the kind of power we expected to make with almost the same set up and less CI's.
oh ok hope it puts 700+ rwhp
06-09-2009, 05:58 PM
#13
I have a set of mild port L92 and a 242/246 custom cam. stock 07 LY6 crank rods and pistons in a 07 GMPP 6.0L block with ARP rod bolts, heads milled .075" and pistons flycut on the intake side. untouched GMPP intake(milled to fit) edelbrock ultra low elbow and a holley 90MM tb. made 580 on the engine dyno, so prolly 500+ at the wheels. Not to bad for a stock short block.
06-09-2009, 06:29 PM
#14
Single plane/Carb intake will have a 20-30 rwtq loss in the midrange from 2500-5500, and just barely touch the same peak number, and extend the power curve from 6200-6800. Definitely run a standard stock style LS3 intake.
My old 415 cube LS3 NA made 540/540, pump gas, 11.5:1, on a stock LS3 port
1 3/4s and a good tune
Louis
My old 415 cube LS3 NA made 540/540, pump gas, 11.5:1, on a stock LS3 port
1 3/4s and a good tune Louis
06-10-2009, 11:00 AM
#15
[QUOTE=Louis;11730869]Single plane/Carb intake will have a 20-30 rwtq loss in the midrange from 2500-5500, and just barely touch the same peak number, and extend the power curve from 6200-6800. Definitely run a standard stock style LS3 intake.
My old 415 cube LS3 NA made 540/540, pump gas, 11.5:1, on a stock LS3 port 1 3/4s and a good tune
Louis[/QUOTE
Wouldn't the losses and gains depend on cubic inches, cam profile etc.?
Plus if we're talking about drag strip perfromance, doesn it matter what the torque losses are at 2500 rpms if your converter is flashing at 4500+ (like mine) and will never see that low rpm during a run?
My old 415 cube LS3 NA made 540/540, pump gas, 11.5:1, on a stock LS3 port
1 3/4s and a good tune Louis[/QUOTE
Wouldn't the losses and gains depend on cubic inches, cam profile etc.?
Plus if we're talking about drag strip perfromance, doesn it matter what the torque losses are at 2500 rpms if your converter is flashing at 4500+ (like mine) and will never see that low rpm during a run?
06-10-2009, 12:19 PM
#16
He was building a 400+ cube motor. I have back to backed that exact combo, I shared my results!
It all depends on the combo! You and I both know that. What may work for one guy may not work for another.
If you go single plan NA, you need to spin it higher to take advantage of it.
It all depends on the combo! You and I both know that. What may work for one guy may not work for another.
If you go single plan NA, you need to spin it higher to take advantage of it.
06-10-2009, 12:49 PM
#17
I was asking because I am doing the swap soon, parts are almost all in.
vic jr, 115mm tb, 100mm maf, bigger airlid, intake elbow blah blah.
I defianatly plan on spinning it higher, my motor falls off hard after around 6400 rpms, I think mainly because it's starving for air sucking through the stock L76 intake and 90mm tb, 85mm maf.
Louis, you guys are more road race right? so giving up that low end performance is definatley not something you guys would want to do I would imagine.
I'm running a hydraulic set up so if I can keep it at 68-6900 rpms and get that extra air the motor needs in there that would be ideal.
I'm not gonna sell my old stuff just yet though
I'll wait too see how she does at the track first.
vic jr, 115mm tb, 100mm maf, bigger airlid, intake elbow blah blah.
I defianatly plan on spinning it higher, my motor falls off hard after around 6400 rpms, I think mainly because it's starving for air sucking through the stock L76 intake and 90mm tb, 85mm maf.
Louis, you guys are more road race right? so giving up that low end performance is definatley not something you guys would want to do I would imagine.
I'm running a hydraulic set up so if I can keep it at 68-6900 rpms and get that extra air the motor needs in there that would be ideal.
I'm not gonna sell my old stuff just yet though
I'll wait too see how she does at the track first.
