JUNK L31 Top End

[34blazer]

I have always wanted to duplicate this engine. It made over 425 ft/lbs of torque from 2,400-5,100 rpm with peaks of 487 ft/lbs @ 4,000 and 416 HP @ 5,000. All from a set of production vortecs, a 210/220 roller cam on a very stock EFI friendly 114* LSA. My build will have a touch less cam and siamesed SLP runners. Whoever said 1 3/4" header primaries and dual 2 1/2" exhaust could not make torque!

http://www.gmhightechperformance.com...k/viewall.html

5.slow guys do it all the time, and improve the whole torque curve.

[woody80z28]

I have always wanted to duplicate this engine. It made over 425 ft/lbs of torque from 2,400-5,100 rpm with peaks of 487 ft/lbs @ 4,000 and 416 HP @ 5,000. All from a set of production vortecs, a 210/220 roller cam on a very stock EFI friendly 114* LSA. My build will have a touch less cam and siamesed SLP runners. Whoever said 1 3/4" header primaries and dual 2 1/2" exhaust could not make torque!

http://www.gmhightechperformance.com...k/viewall.html

Wow. That is impressive. Anybody got a Vortec TPI setup for sale? haha

[Fast355]

Wow. That is impressive. Anybody got a Vortec TPI setup for sale? haha

I really have an itch to try a set of rhoades lifters in this engine too. I saw a 224/224 cammed 5.3 truck gain over 40 ft/lbs to the wheels while only sacrificing 4 rwhp! It made more torque with the comp grind cam and rhoades lifters than the stock cam.

[Hog]

I did a 355 with the SDPC lower intake, SLP runners, stock Vortec heads/pinned rocker studs, LT4 Hotcam kit(LT4 hotcam, LT4 springs, 1.6:1 roller rockers etc), 1-3/4" shorty headers/aftermarket 2 3/4" y-pipe into an 85 IROC-Z. The car went from 15.4@88 to a 13.5@99mph with a 1.8 60ft with 245/50/16 all season rubber with 3.42 rear, stock converter in the 700r4 trans. 32 lb/hr injectors and the stock untuned 305 TPI chip. The owner added a larger MAF and said he cracked the 12's, but I didnt see a slip for the 12's.
He has held 1st gear a few times to over 7000rpm, its not making any power up there but it sounds cool.
Skoggin Dickey says they did the exacts same setup and got 360hp out of it, so that GMHTP SOSN got another 60hp on top of that. I hope that eceryones numbers are on the level.


EDIT And yes, Ive told him a thousand times to at least get the ECM calibrated, or even get it on a blackbox or 411 PCM so I can tune it, but no. I think he enjoys 2 footing it at every stoplight, and having it stall in town when the A/C is on.

I think I would like that 210/220 Something Old SOmething new cam in my truck. Can argue with the numbers it put out.

The torque is fine, but bigger economical power is tough from the GEN 1/1E engines. I dont want to go to the GEN 3/4 engines, but all roads are leading me there.

peace
Hog

[Hog]

That SOSN cam appears to be a Comp Cams 210/220-.500/.510-114-110
Basic Operating RPM Range: 1,000-5,000 RPM
Duration at .050" lift: 210 int./220 exh.
Valve lift with 1.5 ratio: 0.500 int./0.510 exh. lift

I cant beleive they got 420 hp and 495 lb/ft of torque out of a 355 using a TPI intake.

peace
Hog

[Fast355]

That SOSN cam appears to be a Comp Cams 210/220-.500/.510-114-110
Basic Operating RPM Range: 1,000-5,000 RPM
Duration at .050" lift: 210 int./220 exh.
Valve lift with 1.5 ratio: 0.500 int./0.510 exh. lift

I cant beleive they got 420 hp and 495 lb/ft of torque out of a 355 using a TPI intake.

peace
Hog

I can believe it.....Never have run the Accel runners, but I have run the stock runners and a set of siamese ported SLP runners. The SLP setup on a 383 with less cam than the one above made 380 RWHP and 430 RWTQ through a 4L60E, heavy 2 piece driveshaft with carrier bearing and 9.5" corporate 14 bolt. I bet the Accel runners would make even more midrange torque than I was making with a slight trade off on the top end.

[Fast355]

I did a 355 with the SDPC lower intake, SLP runners, stock Vortec heads/pinned rocker studs, LT4 Hotcam kit(LT4 hotcam, LT4 springs, 1.6:1 roller rockers etc), 1-3/4" shorty headers/aftermarket 2 3/4" y-pipe into an 85 IROC-Z. The car went from 15.4@88 to a 13.5@99mph with a 1.8 60ft with 245/50/16 all season rubber with 3.42 rear, stock converter in the 700r4 trans. 32 lb/hr injectors and the stock untuned 305 TPI chip. The owner added a larger MAF and said he cracked the 12's, but I didnt see a slip for the 12's.
He has held 1st gear a few times to over 7000rpm, its not making any power up there but it sounds cool.
Skoggin Dickey says they did the exacts same setup and got 360hp out of it, so that GMHTP SOSN got another 60hp on top of that. I hope that eceryones numbers are on the level.


EDIT And yes, Ive told him a thousand times to at least get the ECM calibrated, or even get it on a blackbox or 411 PCM so I can tune it, but no. I think he enjoys 2 footing it at every stoplight, and having it stall in town when the A/C is on.

I think I would like that 210/220 Something Old SOmething new cam in my truck. Can argue with the numbers it put out.

The torque is fine, but bigger economical power is tough from the GEN 1/1E engines. I dont want to go to the GEN 3/4 engines, but all roads are leading me there.

peace
Hog

That setup sounds horribly out of tune. With a milder LT4 cam in a 8.9:1 350 with ported vortecs, stock runners, unported base I was making good power until ~5,000 rpm and trapped 94 mph in a 5,600 lbs brick.

The shorties, Y-pipe and lack of tune were killing it!