VincentZ28

iTrader: (2)

This build is going into my 1991 Z28. The build specs are...
355 short block
Vortec 062 ported with 2.02/1.60 valves
Vortec Manifold semi ported with injector bungs in the runner grinded down
Edelbrock runners fully Siamese with only 1 1/2 inches of divider in the runner left.
Ported plenum for 52mm TB
52mm precision TB
27lbs LSX injectors from South Bay Injectors
ZZ9 TPIS cam
LS7 lifters
Dyno Dons 1 3/4in headers
Manley Valve Springs up to .550 lift
700r4 Trans with 2400 Stall Converter.
3.23 Gears
Dual Cats
.028 Head Gasket
3in Cat-Back Magna Flow system.

What HP do you think it will make?

VincentZ28

iTrader: (2)

midias

Looks good, the 2.02 intake gave a small improvement but the real gains will be on the exhaust side.

VincentZ28

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Dyno Dons Headers with EGR crossover tube.

VincentZ28

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More stuff

VincentZ28

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Adding more stuff

Fast355

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With a good tune it should make atleast 380 HP to the flywheel and well over 400 ft/lbs.

VincentZ28

iTrader: (2)

I think it might be around 340-360rwp and close to 400rtq

jokerZ71

What are the specs on that cam?

Fast355

iTrader: (2)

212/226 .483/.520" lift on a 112* LSA

I don't feel its the cam thats going to hold him back, rather the shorties and california EPA **** approved cats.

I am making 374 to the wheels in the Express. But the cam I am running has alot more lift and the L31 marine intake has substantially shorter runners than his setup. Not to mention I am running long tube headers with 2.5" high flow 200 cell cats.

VincentZ28

iTrader: (2)

The exhaust will not hold this engine back. Remember the headers are 1 3/4in with 3in collectors.

Fast355

iTrader: (2)

They are shorties and do not have much collector length. Then I am sure california will not let you run a 200 cell count metallic core high flow cat. IIRC cats have to be Carb approved and be in stock location. That means you can only have ceramic dual bed cats and a single exhaust. I picked up nearly 20 ft/lbs average at the tires going from ebay special 1 3/4" primary shorties with 3" collectors to hooker super comp 1 3/4" to 3" collecter tuned length long tubes on the 350 hp 305 in my Vette.

Dyno Don

iTrader: (7)

Damn....
What do they put in the drinking water in Hurst Texas?

Fast355

iTrader: (2)

Don't misunderstand where I am coming from Dyno Don. I understand you have to work under some BS laws in CA and you do a nice job complying with their bureaucracy.

That being said, nothing beats the a tuned primary long tube, especially with a merge collector design as far as power gains across the RPM range go.

Ceramic core catalytic converters will always pose a restriction. Case in point, I recently made some alterations to a 2014 5.6L Nissan Titan with 800 miles on the truck. STOCK the 4 wheel drive truck put down 288 RWHP/317 RWTQ on a Dynojet. The truck has 4 cats total. The rear cats are a pair of large 5" diameter round ceramic units mounted in a pipe downstream of of the rear 02 sensors behind each main manifold/cat, connected via a 2 1/8" od pipe that measures 1.97" ID. The factory exhaust was 1.97" ID into a dual in/single out muffler and a 2.34" ID pipe exiting the muffler. Replaced them with a pair of 2.5" od catless pipes. Gained 10 RWHP on a Mustang dyno in addition to the 18 RWHP I gained from the dual 2.5" exhaust and 14 rwhp that came from the Airaid MXP 4" CAI. I then leaned the air/fuel ratio out through the midrange, threw a few degrees more timing at it in the low-midrange and pushed out 330 RWHP and 400 RWTQ from an otherwise untouched truck on 93 octane E10. Went back after putting E85 in the tank and gained another 6% hp/tq with a little extra spark advance in the mid-high rpm range. I left the dyno putting down 349.7 RWHP @ 4980 and 424.8 RWTQ @ 2970 on a dynojet. On the PRT Dyno these charts came from, I would put down about 10% less or 317 HP to the tires. The power difference between the 04 shown and the 14 is larger factory camshafts as well as variable intake cam advance on the newer truck.

Within the next few months it will be getting a set of headers that are 1 3/4" primaries, very close to tuned length, with a 2.5" merge collector. Power gains on the prototype where 32 RWHP and 26 RWTQ on truck that was only making 249 RWHP on a Mustang dyno, about ~275 RWHP on a Dynojet. A second truck with a set of pacesetter 1 3/4" primary to 3" collector long tube headers was tested and the only place they even compared was in the 5,000+ RPM range. Torque was unimpressive with the 3" collectors. As you can also see the trucks do not gain much HP from the 93 octane because they already run 35-37* total timing above 5,500 RPM stock. 93 octane allows a nice quick advance curve that gains a ton of torque though and prevents the knock sensors from retarding the timing already in the factory tune.

Here is what a good set of catless long tubes can do over a stock manifold design.

Fast355

iTrader: (2)

As for the difference between an unequal length header with oversize collector and properly sized merge collector on an approximately equal length setup. Look at all that area under the curve. All that extra torque would increase trap speed and help reduce ET if the tires could plant the torque. There was a VERY NOTICEABLE seat of the pants difference between the two trucks.



I need to hookup and fire up my old flatbed scanner and scan the dyno sheets pertinent to my 1980 corvette setup. Suffice to say the average torque gain was 20 ft/lbs with a similar gain in peak HP. Went from unequal length shorties and 2.5" compression bent pipes to equal length long tubes and pypes 2.5" dual exhaust with a X pipe reusing the same Hooker Aerochamber mufflers. No cats on either setup. The 305 went from 290 RWHP to 310 RWHP and picked up from 300 RWTQ to nearly 330 RWTQ at peak.

Fast355

iTrader: (2)

That being said I think he has the potential to make very good power, although using the TPI based intake, smallish cam, and the shorties will hurt his overall horsepower potential of the heads he is running. Its not that shorties don't flow, they don't really help scavenging all that much. Scavenging and torque production go hand in hand with finding the right amount of overlap.

With my old L31 in my Express I am running a a 3.34" ID intake into an 85mm maf, feeding a GM marine MPFI intake modified for a LS1 84mm throttle body that has had some porting with runners a little shorter than a TPI base plate, Edelbrock ETec 170s out of the box, a comp cams 271/276 @ .006, 215/220 @ .050, .534/.547 (w 1.6:1), 114* LSA cam installed on a 110* ICL (4* advanced) into doug thorley tri-ys, 2.5" pipes into 3" cats, back to a dual 2.5" in/single 3" out muffler. Using a tuned LS1 PCM and turning a 4L80E with a locked converter it put this down. In something that didn't weigh 6,200 lbs, I would put a larger 228/236ish cam in it even in a daily driver. Prior to the heads/headers/exhaust change I was making only 330 rwhp and 330 rwtq.

Orr89RocZ

iTrader: (20)

320-330 whp

Fast355

iTrader: (2)

My guess was 310-320 RWHP, maybe 10 more with a locked converter. I think it will probably put down 350-360 RWTQ.

I had a 10.5:1 383 with more cam, 2.05/1.60 valves in vortec heads flowing 265/218 @ .500" and ran a Reed cam with over .080" more valve lift than the ZZ9 cam, ran a ported 3817 intake base, fully siamessed SLP runners and a fully ported plenum with a 58mm throttle body, doug thorley Tri-Ys, 2.5" catless duals, and put down 380 RWHP through a locked converter.

Dyno Don

iTrader: (7)

I'm not going to get into a pissing match, but all of that goes out the window when you bolt on a street exhaust system (coming from someone who's been in the exhaust business for 50+ years).

Fast355

iTrader: (2)

Don't have to get into a pissing match to see the proof I posted above. Same engine, same setup, different headers and both had a street exhaust system on them. Not all engines are the same, but that engine must be especially sensitve to collector size and design.

I have also personally had an exhaust that I did away with the dual in/single out muffler, used a 2.5" to 3" merge Y and a straight through design muffler and saw gains of 12-15 ft/lbs across most of the powerband. Scavenging IS power. It is possible to build an exhaust that works almost as well as well as open headers and in many cases make more torque in the process. I know from my setups I will never again run a chambered muffler or crossflow, they cost too much HP.

VincentZ28

iTrader: (2)

Almost ready to start.

Fast355

iTrader: (2)

Looking great! Shouldn't be too hard to get dialed in and running hard.

VincentZ28

iTrader: (2)

I already a have a similar combo chip in it just to get running. My compression maybe a little too high but I'll just back down the timing in the chip. The compression may be around 10.3-10.5.

MoJoe

iTrader: (5)

With 64cc head, .028 gasket, and guessing 5cc for flattop w/ valve relief pistons, and stock .025 deck height, the calculator says 10.07:1. If you had the block decked at all, the CR goes up. With deck at .015 CR goes to 10.3.

With the 212* intake on the cam, that should bleed dynamic compression down to the low to mid 8s. If actually starting with 10.3, you should still get a manageable DCR around 8.8.

This is similar to where I am heading, so I am very interested to see your results.

VincentZ28

iTrader: (2)

Oh I forgot to mention, the pistion sits .016 in the hole.

VincentZ28

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It's alive! Click or tap on the picture for Video.

Fast355

iTrader: (2)

Good deal! How is it runnig?

VincentZ28

iTrader: (2)

Look at the video. I have to fix the vacuum leak.

Fast355

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Will have to go online to see it, not showing up from my phone.

1989GTATransAm

iTrader: (3)

Hmmm, link does not work with my computer. Congratulations on getting it running.

Fast355

iTrader: (2)

Sure its a vacuum leak and not just the IAC having to stay too open. I would do the IAC reset by jumpering a to b on the aldl, turn the key on but dont start the engine, the iac will start clicking, after 10-15 seconds with the key still on disconnect the iac connector. Now you can start the engime and adjust the throttle plates for a solid idle speedof 600 rpm. Then shut the engine off, reconnect the iac and see where it winds up.

VincentZ28

iTrader: (2)

I drove the car for a short distance because it is not registered nor insured. At 50mph I dropped it into 2nd gear and it spins the tires like hell with 3.23 gears. Now it just needs a final tune. It will be done by Kevin91.

90camaro355rs

bad a ss I like seeing these cars come back to life!

TxTtopZ

Nice to see someone else still paying attention to the old small blocks. Looks good too! Seems like all I hear, see and read about are the LS motors.
I have changed my mind over and over as to which set-up I want. LSX, 305 of some sort, 355 LTR, etc. etc.
The latest idea I have bought parts for is a 383 MR...lol We'll see how long that lasts.

Anyway, The exhaust figures on your heads are nice to say the least. The cam should work fine... I have never been a fan of the exhaust on these cars, but I think you have done all you can do given the circumstances... Output wise... I would hope 320ish RWHP/400ish RWTQ with the proper tune on a DynoJet. Who's tuning the thing?

Nevermind, just read above...

VincentZ28

iTrader: (2)

Video

VincentZ28

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cuisinartvette

Would be curious to see what the heads would do on a 4.00 in bore

Still a nice improvement, solid 20cfm on intake and lotson the exh. THat wide exh split should carry the powerband farther.

Should be lots of fun on the street. Like the poormans superram.

Have not worked with the Vortec base before is there room to push the walls out around the injector bung and carry them back? What about the roof?

Enjoy your new ride

Dyno Don

iTrader: (7)

Honestly, that Vortec manifold is one of the biggest pieces of crap Edelcrock ever built.
They should have designed it after the 3860.
The walls are too thin as is the roof.
We welded one up and ported it and the best it flowed was 290CFM.
To do that we had to raise the injector bungs.
A big pain for nothing.

grumpyvette

is that a miss print? 290cfm is far higher than any stock production 906 Vortecs head flows even with most port jobs

VincentZ28

iTrader: (2)

Nope! Not a miss print but a lot on welding and grinding and hours was spent.
My manifold and heads flows about the same around 244cfm. They should work pretty good together with a mild cam.

cuisinartvette

heard they werent all that hot but sheesh after all that 290? Id be pizzed lol

Even with no welding finding the limit of any base takes stupid amounts of time.

What do they do out of the box?

Fast355

iTrader: (2)

Mine was about 230-240 out of the box, varied on a few runners. With some work on the runners and injector boss I got it up to the same 260 cfm range my heads flow. No welding needed. If you want over 290 CFM what are you doing with TPI anyway??? Just go with a FIRST intake without electronics and problem fixed.

VincentZ28

iTrader: (2)

Mine flowed 218-220

Dyno Don

iTrader: (7)

Not really, if you want to make 400/430 RWHP like some of do, you need to flow over 300 on the base.
<<<<<<<

The first is a good start, but it will not get you there as is.

cuisinartvette

20cfm isnt a bad gain

Vortec out of the box? What did you use for a fixture?

VincentZ28

iTrader: (2)

Any e.t's or hp numbers? What all did you do?

Fast355

iTrader: (2)

Edelbrock Vortec out of the box I bought from a member here.

We used the cylinder head, flowing 260ish cfm as a jig and used a cylinder head jig on the table. Very similar to this setup.



We were pulling 255-260 through the entire induction system @ .550" lift. Throttle body through chamber with a 4.030" bore restrictor. The mostly siameses SLP runners we found were not a restriction at all. Nor were a pair of oversize ASM runners. I used shorter LT4 injectors and modifiedthe Iintake to where the injectors seated but stuck out as far as possible. Took some of the injector boss area away and opened up the intake slightly. The edelbrock casting was not the smoothest nor greatest out there. Definately not the foam cast stuff the OEMs are using now days.

As for track times....It was in a 5,300 lbs 1983 G20 fullsize conversion van with a stock 1600 rpm converter in the 700r4 and 3.08s. Ran numerous 14.1-14.2 passes @ 99-101 mph. 9:1 compression with a 214/218 @ .050 reed cam. It had a custom CAI with 3.5" piping, doug thorley tri-y headers, dual catless 2.5" exhaust, and a 7730 running SAUJ4 v4 tuned by me. The heads had 2.05/1.60 valves, Lunati springs and Crane 1.6:1 full roller rockers.

Keoman

iTrader: (3)

What would you suggest for a Vortec Carb manifold in it's place?

VincentZ28

iTrader: (2)

Ok here's a short action shot of the cat in action.

1989GTATransAm

iTrader: (3)

Not bad at all. Just needs a final dyno tune to extract the last bit of horsepower.