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Vortec head pics up

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by dyeager535, Dec 18, 2001.

  1. dyeager535

    dyeager535 1 ton status Premium Member

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    If anyone wants to see a few pictures, www.dorianyeager.com/index2.html
    Why insist on counting when the ring gear has the tooth counts stamped in?
     
  2. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    Cool beans. Did you get them ported? I want to get mine ported so the flow efficency could at least crack 60%, or at least high 50s.

    <a target="_blank" href=http://new.wavlist.com/movies/031/ag-blow.wav>"I ain't nobody, dork."</a>
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    No porting, I was just happy that they outflow the old camel humps heads. I may be wrong, but with the low end power I'm going for, it wouldn't help me any to port them.

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     
  4. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    Hey Hey Hey post 1,000

    I'm just porting mine to get big #s. You know 1 cube for 1 hp. This engine analyzer program is fun stuff, I've spent waaay to much time on it.

    <a target="_blank" href=http://new.wavlist.com/movies/031/ag-blow.wav>"I ain't nobody, dork."</a>
     
  5. '73 K5

    '73 K5 1/2 ton status

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    Don't port those heads man. Its not going to help and more than likely it would hurt. I did research on this when I bought my Vortec heads. Porting on some old 882 casting heads or something is a great idea, but I've heard a bunch of people, magazines, mechanics say not to touch the Vortec's.

    '73 K5
    Chevy good...Ford bad
     
  6. Twiz

    Twiz 1/2 ton status

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    Pop a valve Dorian. The casting is preety clean for factory O stuff. They also have a nice path around the valve guide boss.

    Acording to some G.M. service brochure I saw on 'vett heads (I think it applies to the vortecs too)
    The intake charge is suposed to tumble (flip end over end) and swirl (spin around the bore) once during the intake stroke. This is suposed to keep the fuel atomized and off the cyl walls.


    <font color=blue>Wow factors
    A SBC (4" X 3.48") with 2" intake-valve at 6,000 RPMs:
    1- The piston reaches a maximum speed of 60 MPH
     
  7. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    So not even smoothing up the casting a pinch would help? I mean I'm talking just cleaning it up, not taking out alot of meat.

    <a target="_blank" href=http://new.wavlist.com/movies/031/ag-blow.wav>"I ain't nobody, dork."</a>
     
  8. '73 K5

    '73 K5 1/2 ton status

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    Most of the things I've read say not to touch them at all. That the Vortecs are so good out of the box that any extra work isn't necessary. And that you run too much of a risk of taking off too much even with intentions of just taking off a little bit. I'll try to find some of the articles I'm talking about.

    '73 K5
    Chevy good...Ford bad
     
  9. Triaged

    Triaged 1/2 ton status

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    Are you sure those are the correct roller rockers?...
    I thought you had to have self-aligning rockers for Vortec heads because they don't have guide plates.

    '71 Blazer CST w/ a 400sbc, 4" lift, 36" Supper Swampers, and alot of rust
    <a target="_blank" href=http://community.webshots.com/user/triaged>See it Here </a>
     
  10. dyeager535

    dyeager535 1 ton status Premium Member

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    Unless GM ported them, they definitely shouldn't be. : ) I noticed they are smoother than other castings I've seen, but not ported smooth. I just think the castings are that good/clean. Casting technology must have changed a bit since the 60's : )

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     
  11. dyeager535

    dyeager535 1 ton status Premium Member

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    Those ARE self aligning rockers. The "guides" on the rockers fit over the valve stem, and are right at the tip.

    Which is why you don't want to run self aligning rockers on non-self aligning heads...the guides can hit the retainer.

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     
  12. Triaged

    Triaged 1/2 ton status

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    Cool...just wanted to make sure. Is the alining part on the bottom and not visable from the top? How much were the rockers?

    '71 Blazer CST w/ a 400sbc, 4" lift, 36" Supper Swampers, and alot of rust
    <a target="_blank" href=http://community.webshots.com/user/triaged>See it Here </a>
     
  13. dyeager535

    dyeager535 1 ton status Premium Member

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    Yes, they "hang down" off the tip of the rocker. Pretty cool idea if you ask me. (although its been around a long time)

    IIRC, they were $250, but I had heard things (and know) about aluminum fatiguing in certain uses. I figured since this is intended to be an 200,000 mile life motor, I should pony up for the steel rockers. Besides, at the time, they were about the hottest ticket for "freeing up" power for these heads. This motor is kind of an experiment in mileage, so any little bit helps, and I figure if I have the money now, I better do it "right" (in my eyes) so I don't have to go back in later.

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     
  14. '73 K5

    '73 K5 1/2 ton status

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    I just looked on Summit for the rocker arms....$322!!! Ouch. I'm probably going to put some Pro-Form roller rockers on my Vortecs when I put my next cam in.

    '73 K5
    Chevy good...Ford bad
     
  15. dyeager535

    dyeager535 1 ton status Premium Member

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    Call locally. I think thats a rip off. Like I said, mine were about $250, and those were what I considered top of the line. Mine were from the local speed shop. I may have gotten a bit of a deal, but not that much!

    Local speed shop will meet or beat Summits price, and thats not asking them to, thats their normal pricing.

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     

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