Basic "vortec" engine setup, valve springs

Discussion in 'Engine Topic' started by MadMike, Oct 18, 2015.

  1. MadMike

    MadMike Administrator Staff Member

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    I'll try and keep this simple.
    I have a 1990 roller block. Vortec heads.
    I built the engine with an edelbrock TBI hydraulic cam. I THINK I used the TBI cam valve springs.

    Well, I'm getting rid of the TBI cam and I'm going to put a "regular" roller cam into the engine. The purpose of this engine is reliability, dependability, efficiency - not maximum effort.

    So my question: Can I run the still new TBI valve springs with a basic, not aggressive roller cam, or do I need to replace my springs with the cams recommended springs.

    AN EXAMPLE: I'm looking at the Comp Cams XR258HR which recommends a spring of 981-16
    I have no idea of what the TBI camshaft springs are/were - apparently this is obsolete stuff now.

    I'm trying to keep the cam simple because - again, I want dependability, and I don't want to pull my heads off and machine them.

    Oh, and the other stupid question... I have a double roller timing chain, which was matched to the cam. Can you run the same chain (sprocket) on a roller cam - or is that different/specific too?
     
  2. Damon

    Damon Veteran Member

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    Factory-style hydro-roller cams require a different timing chain set (the GMPP single roller works great at a budget price), a cam retaining plate, roller lifters (obviously) and the lifter-retaining spider and "dogbones". Plus shorter sticks to work with the taller roller lifters.

    Not sure on the "TBI springs". If you mean factory stock springs like came on a TBI engine, they're no different than those used on millions of SBC heads. 981s are a nice upgrade in "slightly hotter than stock" engines. I've used them on stock-ish hydro-roller cams and they do much better than stock valve springs. The inner dampener coil won't fit over the big "foot" at the bottom the Vortec's valve guide boss without machining. Or you could just do what I did- take the dampener coil out.
     
  3. Dogwater

    Dogwater Veteran Member

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    I did a writeup on springs for Vortec heads, its on the last page of the sticky for " Vortec cylinder heads The Definitive Guide". Even though this was a flat tappet engine I did this to I'm sure it'll work with a roller cam of your size. These bee hive springs are used on LS6 engines. No machining required.
     
    Last edited: Oct 19, 2015
  4. kimosabi

    kimosabi Veteran Member

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    A set of beehive springs work in a vortec head?
     
  5. BigEd36

    BigEd36 Veteran Member

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    Kimosabi, you can use LS6 beehive valve springs on vortec heads. Since the LS engines use 8mm valve stems you will need aftermarket retainers, GM doesn't make any retainers to fit the beehives to the 11/32 valve stems of the SBC. Comp Cams #787-16 will fit beehive springs to the 11/32 valve stems, they're about $52 at Summit. The #12499224 LS6 beehives are about $61. The beehives install at 1.80", and are good for .550" lift. However, they're a little soft for an aggressive ramp cam like the Comp Extreme cams, they're more suitable for "lazier" cams like the ones used by GMPP. A vortec longblock with the beehives and the #10185071 ZZ4 camshaft (232.97 at Summit) with a good dual plane intake, 4 barrel carb, and long tube headers with free flowing exhaust will give you 350-360 hp for cheap!

    Edited to add: For the same $$$ the GMPP LT4 Hot Cam, #24502586 makes about 380hp, but it does give up some lowend torque.

    Comp Cams does have beehives available that will work with their cams and the 787-16 retainers.
     
    Last edited: Oct 21, 2015

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