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anyone running vortec heads on a TBI 350?

Discussion in 'The Garage' started by sled_dog, May 23, 2003.

  1. sled_dog

    sled_dog 1 ton status

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    I have a friend planning a 454 swap for his dad's Vortec 350 truck. If he does I want to try and get his Vortec heads off of him. Anyone running a set of stock Vortecs on a TBI motor? Wondering about the performance gains. Was thinking of using the Vortec heads and an Edelbrock RPM air gap manifold with throttle body adaptor plate instead of one of those TBI Vortec intakes.
     
  2. 88Silverado

    88Silverado 1/2 ton status

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    The Vortec heads will flow better than stock heads.
    If you plan on running the same cam or a cam up to .460 lift, the heads will be fine. The use of the Performer with the TBI adaptor will also improve performance. I think its a better way to go instead of the TBI manifolds. Not sure you will notice much difference between the performer and RPM Airgap.
     
  3. sled_dog

    sled_dog 1 ton status

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    my goal is somewhere between 220 and 250 HP at the rear wheels. Think its unreasonable? Stock 350 puts about 160 to the rear I am told. When I get it I am gonna spend the money and hit the dyno jet. I know its just a 4wd truck but I am a mad gear head and want to do it. It will be my first real hop up project. FOr now I think its just gonna be 1.6 ratio roller rockers, headers, ported throttle body(started porting it today), injector spacer, tb spacer, headers, dual exhaust(undecided on mufflers), and fuel pressure regulator. Not hoping for a great deal otu of this. Maybe some underdrive pulleys and definetally a 180 degree stat. May get a custom chip burned though that will probably wait for vortec heads. Doubt i will cam it much if at all. 1.6 rockers ought to do fine i think.
     
  4. sled_dog

    sled_dog 1 ton status

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    ok relooked at the idea and yeah will cam it up but stay under the .450 lift I believe. I have a friend who is a TBI chevy motor guru I will talk to him and get him to help me build it. In fact he is the one I think I can get some heads off of.
     
  5. jjlaughner

    jjlaughner 3/4 ton status

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    Keep us/me updated, I'm wanting to do that also! /forums/images/graemlins/thumb.gif

    If I ever find a damn job! /forums/images/graemlins/angryfire.gif
     
  6. 84_Chevy_K10

    84_Chevy_K10 Banned

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    250 HP should be no problem for a Vortec 350. The stock one puts out 255 at the crank.
     
  7. 88Silverado

    88Silverado 1/2 ton status

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    [ QUOTE ]
    Doubt i will cam it much if at all

    [/ QUOTE ] /forums/images/graemlins/eek.gif
    Then why waste your time /forums/images/graemlins/confused.gif
    The stock cam grind is very conservative. For about $150 install a good Comp or Crane cam and let the rest of the combo do its thing....Breath /forums/images/graemlins/thumb.gif

    In case you havent seen this, some pretty good basic wake-up mods to get some pretty good power :
    http://www.73-87.com/chp/gm350.htm
     
  8. sled_dog

    sled_dog 1 ton status

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    yeah I have realized its pointless without the cam
     
  9. heavy4x4

    heavy4x4 1/2 ton status

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    I've been throwing this idea around too. I've put together a couple of engines via Desktop Dyno, and with vortec heads, tbi, and various cams, I'm coming up with about 250-260 hp at 4500rpm and around 350 lb-ft of torque at 3000rpm with about 325 off idle. I can give you the cam numbers if you want.
     
  10. ZooMad75

    ZooMad75 1/2 ton status Premium Member GMOTM Winner

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    [ QUOTE ]
    ok relooked at the idea and yeah will cam it up but stay under the .450 lift I believe.

    [/ QUOTE ]

    Depending on who you talk to the max lift on stock Vortecs are anywhere from .450 to .480 due to the wide variance, check it for yourself. I have a buddy running a set in his S10 with .488 lift and stock guides/springs with no contact. Still check the clearance yourself though. The biggest limitation is retainer to guide contact. If you got a set of vortecs you'll notice the guides are huge on them. Comp Cams sells a tool to cut the guides down and open the spring pockets to run a conventional size valve spring. The stock vortecs are small and may not live up to the loads of a higher lift cam even with the guides cut.

    For the cost, its cheaper to cut the guides now and install the new springs. It will be a lot better to do it now since you can't cut the guides with the heads installed.

    I have a set of Vortecs to install into my '69 Nova that I need to make the modifications to before I install them. I've checked and a machine shop quoted around $100 to cut the guides, which is about the cost of the tool.
     
  11. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

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    I've got a complete motor that I am trying to get my hands on that already has the Vortec heads and an Edelbrock Performer intake. Anyways...

    [ QUOTE ]
    I've checked and a machine shop quoted around $100 to cut the guides, which is about the cost of the tool.

    [/ QUOTE ]

    Where can I find this tool for $100? Anyone?

    -Dan
     
  12. dyeager535

    dyeager535 1 ton status Premium Member

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    I think Crane or Comp sells one. Guess if you can use it, then resell for $50, it wouldn't be a bad investment. Can't see anyone short of a machine shop needing one long term.
     
  13. BayouBlazer88

    BayouBlazer88 1/2 ton status

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    Whats the big difference between the Vortec tbi intake and the regular Vortec style intake? Does the regular performer flow much better? And does the tbi adapter plate also have a place to mount the ECU since there are no predrilled holes in 4bl intake? Not to mention, what are you supposed to do about the EGR system since the non-tbi Vortec intake has no EGR provisions? Do you just not use EGR?
     
  14. sled_dog

    sled_dog 1 ton status

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    ecu? I have a feeling you mean MAF and don't know the name of it. ECU is the computer under the dash. I was thinking if I do do the swap I will run the Vortec TBI intake since it has all the places to bolt on the factory stuff. The performer can be used but you have to fab throttle linkage stuff and all. And the regular vortec intake is a multipoint setup thats is 100% different than the throttle body injection system I want to retain. I really want to build a TBI motor that can make a few people around here shut their mouths. TBI 350s have really become the redheaded stepchildren of the SBC performance world. Luckily I have a buddy who feels exactly the sameway and has a lot more knowledge than me /forums/images/graemlins/smile.gif. And my rig won't pass emissions visuals anyway so EGR isn't a worry to me. I am gonna tune it up and I am certain it will pass the actual sniff test just not visual and thats good enough for some people I know.
     
  15. BayouBlazer88

    BayouBlazer88 1/2 ton status

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    Yeah I meant MAF. Should have just said computer and wires on the passenger side of the throttle body.
     
  16. sled_dog

    sled_dog 1 ton status

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    I believe that is an issue. I am sure its just, drill a hole tap it and insert MAF but like I said I would probably just avoid it.
     
  17. dyeager535

    dyeager535 1 ton status Premium Member

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    tbi info

    Some of his info isn't correct ('96+ Vortecs weren't TBI) but it's not too bad. Nothing real specific about YOUR ideas, but somewhat in depth if you haven't read it.
     
  18. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

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    Quoted from http://www.mortec.com/notepg3.htm:

    [ QUOTE ]
    If you are thinking about rebuilding a set of old "camelhump" heads or using a set of 1960's or 70's vintage cast iron production heads, check this out first. The '96 and later smallblock "Vortec" 350 cast iron heads are a very hot item. These "L31" heads with casting number 10239906 and 12558062 or PN-12529093 (bare), flow great numbers for a production head, even better than the Phase 2 Bowtie cast iron head, when fitted with 2.02/1.60" valves and bowl ported. The complete heads (PN-12558060) come with 1.94"/1.5" valves and pressed in rocker studs, but can easily be fitted with 2.02"/1.6" valves and screw in studs. Chamber volumes are 64cc and intake port volumes are 170cc. The Vortec heads have raised intake ports and "fast burn" chambers. The heads require the use of narrow body "self-aligning" rocker arms and center bolt valve covers. They will bolt to any Gen.1 block.

    The price per pair for new complete Vortec "L31"heads (PN-12558060) is about $425.00 (as of 10/1/01), with 1.94"/1.5" valves, springs and retainers from GM/Performance Parts. You can then use the valve sizes you want to use and drill and tap for screw in studs. However, the intake manifold bolt holes are in different locations than previous Gen.1 heads. Only four intake bolts are used on each side to fit the "Vortec" style intake, instead of the usual six on each side. The correct Vortec intake manifold bolts are found under PN-12550027. Use Vortec intake gasket PN-12529094. The stock Vortec L31 valve springs are good for lifts up to .475"-.480" maximum. If you use a cam with more lift you'll need to change the springs and have the valve guides machined down to clear seals and retainers.

    You can redrill and tap the heads to fit the older style Gen.1 intakes, but why bother, Edelbrock has aluminum two and four barrel "Vortec" style intakes out that have the correct bolt hole positions. Edelbrock PN-7116 is their "Performer RPM", dual plane, high rise intake for the "Vortec" heads, while Edelbrock PN-2116 is their "Performer" street dual plane for 4-barrels. They also have two "Vortec" versions of the new "Super Victor" aluminum, high rise, open plenum race manifolds. PN-2912 is for 2-barrel restricted class racers and PN-2913 fits a 4-barrel intake to the "Vortec" RPO "L-31" heads. Vortec style intakes are also available for TBI and TPI setups.

    GM/Performance Parts has a dual plane aluminum four barrel intake that is PN-12366573 and fits the unique Vortec intake manifold bolt pattern. GM also has a aluminum open plenum high rise (PN-12496822) intake for the Vortec L31 heads.


    [/ QUOTE ]

    I'm getting one of the Edelbrock intakes meant for a 4-barrel. That will allow me to use a Qjet adapter, and then use a 1/4" piece of alum, plate to fab an adapter for the TBI to sit on top of. The only other issue I may have is placement of the EGR... /forums/images/graemlins/blush.gif

    -Dan
     
  19. sled_dog

    sled_dog 1 ton status

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    they sell TBI adaptors that are designed for fitting a Throttle Body on top of a 4 barrel intake, let me scrounge up a link.
     
  20. sled_dog

    sled_dog 1 ton status

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