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1996 Vortec vs. Pre Vortec

Discussion in '1992-Present Chevy & GMC models' started by horsepit, May 13, 2002.

  1. horsepit

    horsepit Registered Member

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    Looking to buy another Burb. Do I need to stay with the 1996 or newer? Is the Vortec that much better. I had a 1995 454 in my 3/4 ton Burb. How does the newer 350 and 454 compare?
     
  2. Twiz

    Twiz 1/2 ton status

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    Far more power with the Vortecs, better gas milage too.
    They feel good and solid off the line, and continue into the upper RPM ranges. (The new generation engines are even better)

    A buddy of mine had a '98 ext-cab 4-door long-bed, heavy-duty (4L80E and 14-bolt) with a Small-block.
    That thing was a pig when he first bought it, after it clicked over 10,000 miles on the Odo. It got a whole new personality, It preformed respectibly, considering it was a heavy 3/4 with a small-block. (I have no idea why it took 10,000 miles for it to "come-around", but once it did....it felt really good)

    The Vortecs stand up to all the hype.
    (IMO)
     
  3. ChevyHuny

    ChevyHuny 1/2 ton status

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    I agree, I have owned both engines and the vortec is far better as well.
     
  4. Suburbanite

    Suburbanite Registered Member

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    Here are the HP/TQ specs for the '94-'95 & '96-up 5.7L engine from my Chilton's manual :

    '94-'95 = 200HP@4000RPM & 310FTLBS@2400RPM.
    '96-up = 255HP@4600RPM & 330FTLBS@2800RPM.

    As far as I'm concerned there isn't enuf of a difference in the HP/TQ #'s to make the Vortec a must-buy. Besides with a few mods the pre-Vortec engine can be brought up to Vortec power/fuel economy levels. Granted, the same mods done on the Vortec would up the ante but despite that, I'd still prefere the pre-Vortec engine. Also like the 'cleaner' engine compartment of the pre-Vortec engines. Guess I'm kind of retro in some respects :-).
     
  5. HarryH3

    HarryH3 1 ton status Author

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    The torque peak isn't much different between the two, but the area under the torque curve is much better with the Vortec engines. This means more torque across the entire power band, as evidenced by the horsepower numbers. The HP peak on the Vortec engine is 27.5% higher than on the pre-Vortec engine, and the peak comes 600 rpm higher in the rev range, right where the earlier engines were starting to fall flat on their faces. /forums/images/icons/shocked.gif You can really feel the difference if you drive both of them. /forums/images/icons/cool.gif
     
  6. horsepit

    horsepit Registered Member

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    Thanks for the replies.
    Suburbanite, it looks to me like there is a 55 hp increase. That looks like enough of a reason in it self. What did you do to the pre-vortec to add that much hp?
     
  7. 90K5

    90K5 1/2 ton status

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    Actaully I think TBI's are 210 hp...still a good enough reason to go Vortec. I really like my TBI cause its real easy to work on, and there is less computer crap on it.
     
  8. I have a 95 Yukon with out the Vortec, my buddy has a 96 Suburban with the Vortec. Side by side he pulls away pretty quick from me. His is stock, mine has a K&N filter and a Dynomax cat back system. Pulling a trailer mine is a dog, his handles a trailer better. If I had a choice, I would definitely not go with the non Vortec.
     
  9. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    Definitely go Vortec! Compare the combustion chambers of the older style heads to the vortecs. The old ones still have the open style chamber that the 70's smog-mobiles used. The vortecs have a tight, heart-shaped, fastburn chamber. The port designs also were borrowed from LT1 heads. All making a much more efficent and powerful cylinder head.
     
  10. 95 Silverado

    95 Silverado 1/2 ton status

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    has anyone tried putting vortec heads on a tbi engine while keeping the tbi set-up, how much difference would the better heads make?
     
  11. Suburbanite

    Suburbanite Registered Member

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    I haven't done anything to mine yet but was basing potential HP improvements on what I've read. As a reference, Performance Combos' ads list various add-on combos, their prices & their theoretical HP/TQ/Fuel mileage improvements. As an example their ad on pp 120-121 in the July issue of "Four Wheeler" lists their top combo from $794.95 at 70HP/95LBFT/25% fuel mileage improvement. Their website is: www.performancecombos.com

    Concerning whether Vortec heads can be used on pre-Vortec engines, the answer is yes, but from what I remember reading, (at minimum) a new intake is required. Possibly because the Vortec heads are taller/shorter than the older heads -- don't know which.
     
  12. Suburbanite

    Suburbanite Registered Member

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    HarryH3
    For my purposes, the powerband in pre-Vortec engines is just fine. Yes, I drive fast & sure, I'd like more HP & TQ (more TQ than HP) but I have no need for a hi-revving engine. As it is, I'm uncomfortable when the engine sees 4000rpm, even briefly, during shifts under moderately hard acceleration. My ideal gas engine would duplicate a diesel engines HP/TQ curves. I've developed a simulation somewhat along those lines using Dyno2000, engine development simulation software. I set parameters at low RPM & TQ & came up with a 383 that produces ~500LBFT of TQ up to about 2500RPM & produces a max of ~409HP @ ~5500RPM (irrelevant as far as I'm concerned, because I'd never, ever, purposely rev it that high [rev-limiter would ensure that I didn't]).
     
  13. dyeager535

    dyeager535 1 ton status Premium Member

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    Vortec head/intake difference is the bolts. 8 total intake bolts in the Vortec heads (vertical) and 12 in the earlier heads. (8 angled, 4 vetical IIRC) Also no exhaust crossover, but not sure when the non Vortec castings ended that as well. That means EGR has to come from the exhaust manifolds, not the intake.

    Vortecs are better for numerous reasons. Castings are much "cleaner" (resemble a light port job as cast) and the combustion chambers are more efficient. (higher compression w/same grade of gas, better emissions, more power, better mileage) There are better heads out there, but they aren't cheaper nor as plentiful.

    Of course, when talking about factory installed engine combo's, realize camshafts, ECM parameters, and a lot of other things were changed at the same time as well, so the numbers are not indicative SOLELY due to the heads, but the better heads enable changes on other components to change the overall power output.

    I can understand the desire for a cleaner engine bay, but if you ask me, once you are into injection systems, you might as well go whole hog for as much power as is possible, no matter the complexity. Regardless of how complex the system is, you can still hook a scanner up to it, and you still can't rebuild a MAP or MAF sensor, TPS, EGR, etc.
     
  14. tjayandlisa

    tjayandlisa Registered Member

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    The longevity that comes with vortec is worth it in it self...roller cam...better head design...etc
     

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