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Changing Intake ports to a D shape for better flow.

Discussion in 'The Garage' started by Jack, Sep 13, 2019.

  1. Jack

    Jack XS650 Junkie

    I just logged in or not logged in,there are 5 images page 2
     
  2. Jim

    Jim Beyond the edge, is the unknown. Here be Dragons Top Contributor XS650.com Supporter

    Here's how it looks here. Can you see this one?

    Untitled.png
     
    Machine likes this.
  3. Jack

    Jack XS650 Junkie

    yes I see it, Jim that partial D port looks good;)
     
    Last edited: Sep 30, 2019
    Jim and Machine like this.
  4. gggGary

    gggGary Stop that! Top Contributor XS650.com Supporter

    Yup Jim can see your copy but not the originals.
     
  5. gggGary

    gggGary Stop that! Top Contributor XS650.com Supporter

    I can See THIS one.
     
  6. Bewarethemoon

    Bewarethemoon XS650 Addict XS650.com Supporter

    That’s the last photo I saw too
     
  7. Jack

    Jack XS650 Junkie

    Ok lets try this again, need to know if this images are clear enough for those who might attempt this porting.The first three are in first stage of working floor,last two are second stage of floor mod. Can you tell where I worked the floor in the last two.
    D-P 1.jpg
     
    TwoManyXS1Bs and Bewarethemoon like this.
  8. Jack

    Jack XS650 Junkie

  9. Jack

    Jack XS650 Junkie

  10. Jack

    Jack XS650 Junkie

  11. Jim

    Jim Beyond the edge, is the unknown. Here be Dragons Top Contributor XS650.com Supporter

    Yup, I see 'em all.
     
    Bewarethemoon and Mailman like this.
  12. Jack

    Jack XS650 Junkie

    OK. I'll just reroute images back to my computer in the future
     
    Bewarethemoon likes this.
  13. gggGary

    gggGary Stop that! Top Contributor XS650.com Supporter

    Yup all good now.
     
    Bewarethemoon likes this.
  14. Jack

    Jack XS650 Junkie

    Now I have to figure out how to edit images with this new mac mini:umm:
     
    Bewarethemoon and gggGary like this.
  15. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Looks like you've come in from the combustion chamber side to work the short turn?
     
  16. Jack

    Jack XS650 Junkie

    You were close, this just shows how port images can be deceiving in what areas where modified. These ports were opened up on a mill with incorrect floor
    angle resulting in burring out more towards the spigot inlet area than evenly towards the short turn, the fix is easy but angle is important, I just have to add more JB to raise spigot inlet for correct dimension. When floor is completely raised, then you work from combustion chamber to radius short turn by hand.
    I took another image shot and darkened it up to highlight that defected area. Now you can visually see the mill cut.
    xs d-p.jpg
     
    Last edited: Oct 1, 2019
  17. Jack

    Jack XS650 Junkie

    Had to order some 36 grit cartridges and unfortunately one of the sizes had to be back ordered,so it'll be a couple weeks before I can add images and dimensions to this thread .
     
    gggGary and Mailman like this.
  18. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    I always admired porting and flowbench work, did some back in the '70s, so my experiences with it are quite dated. Studied some of Jerry Branch's ports, read up on his work. Interesting story about his improvements to the 4-cyl Vega head. A GM contract could've really helped his business, but his improvements exceeded what GM wanted, cancelled.

    I recalled studying the "Area Rule" in aerodynamics, where you want to have smooth transitions in cross-sectional area, and wondered if it should apply in port work.
    AreaRulePlots.jpg
     
    gggGary likes this.
  19. Jack

    Jack XS650 Junkie

    Got a PM from a member overseas asking me to D port a head for him so that he might learn this and pass on to his freinds,etc, to be honest here
    I don't care what he does with it cuz I'm flattered that someone 4000 plus miles wants to learn this. I need your input guys, pm or something, I need to think on this.
     
    JAX71224, Bewarethemoon and Jim like this.

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