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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. joebgd

    joebgd XS650 Addict

    330
    91
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    NY
    What does a cartridge look like? Does it go on a rotary tool?
    Also, what is an OW head, it was talked about earlier in the thread.
     
  2. Jack

    Jack XS650 Junkie Top Contributor

    The D Port head is a go to Germany, real nice member who's building a long rod 533 motor with Heiden 750 cylinder kit along with a shell #1 actuating the valves. Gonna do some bowl work on the longside for a straighter shot to the backside of valve hopefully to pick up some more low lift flow and work the Short Turn to max out flow to #1 lift. Valves are Virago and will be cut down to XS stock dimensions with the exhaust valve bottom side radius cut to improve flow.Head will be flowed for port equalization. Can't thank this member enough for giving me this great opportunity, this is gonna be one hard pulling XS750.
     
  3. Jack

    Jack XS650 Junkie Top Contributor

    Got Chris's( Germany member) head back from Hoos racing,Gary did a excellent job of cleaning the head for me and all my porting abrasives have arrived too. I'll be focussing my attention on working the E/P first in great detail the best I can giving dimensions on working the E/P bowl leading up to the guide,modifying the guide length so there's no protrusion which will reduce port resistance there by increasing flow and velocity and working the guide boss area. The guide length mod I've given in years past correlates exactly to length of which Mr Lillie cut his ,so at least I know I was on the right path in suggesting this modification. Now I remind you in order to proceed with these modifications you need to heat the head up to remove the guide. If any of you want to install bronze guides,Kibblewhite guides are exact clones of Mr.Lillies. Now I'm sure other members or racers port their heads or reshape ports differently but I'm showing you how I do it and got great results and feed back.

    If you have any questions or suggestions post them now in order from cluttering this thread
     
    Last edited: Dec 11, 2019
    spungle, grizld1, arcticXS and 6 others like this.
  4. Jack

    Jack XS650 Junkie Top Contributor

    These are the tools and porting abrasive cartridges that I use and you can get them at www.sri-supplies.com or use what ever is confinement for you.
    The springs for the project are Kibblewhite and you MUST use the bottom shim cup for spring stabilization,spring retainers and locks are from
    a Virago 700-750 cuz they're made of better quality steel and lighter than stock retainers
    porting tools.jpg
     
  5. Jack

    Jack XS650 Junkie Top Contributor

    The light that I use for better visibility in the ports ,you can get at Lowes for $15 or use what you have on hand.
    porting light.jpg
     
  6. Jack

    Jack XS650 Junkie Top Contributor

    To attach light to head,I just use a plain old bungie cord. XS porting light.jpg
     
    spungle, Bewarethemoon, Jim and 2 others like this.
  7. Jack

    Jack XS650 Junkie Top Contributor

    Ok here we go, if you decide to remove guides it's important that you thoroughly clean the guides by what ever means you have, if not you'll severely
    gaul the guide bore tearing out aluminum. I make guide points for reinstalling reference.
    Must heat head to 215 to 225 degrees for at least one hour.
    I re edited this post ,just ignore the arrows,this image will edited and posted further down in this thread
     

    Attached Files:

    Last edited: Dec 14, 2019
    TwoManyXS1Bs, spungle, beano and 2 others like this.
  8. Jack

    Jack XS650 Junkie Top Contributor

    This bit of guide information was given to me many years ago and have held off given it out untill Kibblewhites cloning of Lillies guide dimensions.
    For those using stock guides,you might find it useful but I don't cut my exhuast guides like whats given in this document. Looking at Lillies E/G mods,I'm lost as to why he machined them
    that way ,can't image he raised the port roof that much,
    upload_2019-12-12_13-1-40.png
     
    Last edited: Dec 12, 2019
  9. Jack

    Jack XS650 Junkie Top Contributor

    Image of stock guide and modified guide. Looking through guide bore you'll notice a ridge for guide stem, the bottom section leading up to the lip of the ridge
    serves no purpose except for hindering port flow. You can cut the guide two ways,cut it down to 1.400 or 1.335 either way is doable. Shorting the guide down to 1.335 won't compromise valve stability or guide wear because there wasn't any stem support from the beginning. I cut the guide down flush and slightly radius end and use 220 grit on radius to remove any burrs preventing gouging guide bore when reinstalling.
    XS guide length.jpg
     
  10. Jack

    Jack XS650 Junkie Top Contributor

    Hey Chris, unfortunately no the parts haven't arrived probably do to the Holidays coming up,so glad you stop in to say hello.
    Right now I'm in the process of taken photos of the E/Ps with different lighting, angles ,transferring images here and there and editing ,so that you and the other will have a better understanding of what to look for at the short turn on the outer side of the port to exit where you'll see a lot casting flaws, how to work the guide boss for maximum flow at low lifts,etc ,etc. Takes times ,need to get it right for you all to duplicate. By the way this head has really exceptional E/Ps that I haven't seen before,casting was uniform throughout both ports, just need to touch up one of the short turns.
     
  11. Jack

    Jack XS650 Junkie Top Contributor

    Yes and only use chainsaws for texture finish to enhance atomization of fuel mixture over dimpling technique:lmao:
     
    Bewarethemoon likes this.
  12. Jack

    Jack XS650 Junkie Top Contributor

    First mod I'll is the area right behind the guide,it's a small but quick mod that addresses an area that's flat and by using a 1/2" carbide burr cutting it down to1.335 gives a less erupt turn for the flow behind the guide, as to wether or not this works I don't know but this mod was a step I used on my first XS port job when I got started back in 2004 and the flow on this port far exceeded my expectations. So this is our goal here,I've only come close a second time trying to match this port but Yamahas casting flaws kinda limits this but not on this head. There will be several images till I get to the mod
     
    Bewarethemoon likes this.
  13. Jack

    Jack XS650 Junkie Top Contributor

    In this image is I bolt I cut down for guide reference to material removal. The measurement from bolt flange to end by .537 0r 13.65mm diameter.
    Bolt needs a large flange and I use electrical wrapped around bolt for snug fit and to prevent guide bore scoring.
    XS guide bolt  length.jpg
     
    Jim and Bewarethemoon like this.
  14. ReycleBill

    ReycleBill Part Time Tyrannicide XS650.com Supporter

    I remember D ports and Tunnel Rams on small block Chevys, Fords, and Mopars 40 plus years ago. (Couldn't afford big blocks) It worked then, why wouldn't it work now? Watching with lots of interest from here in Greensboro, NC as I dream of riding an XS at Bonneville someday.
     
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  15. Jack

    Jack XS650 Junkie Top Contributor

    You'll insert the bolt through guide bore arrows indicating use of large bolt flange .
     

    Attached Files:

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  16. Jack

    Jack XS650 Junkie Top Contributor

    In this image, if you'll run your finger from the top of valve seat down to the pointer you'll feel a erupt turn the flow encounters behind guide and this is
    the area you modify. Then when completed run your finger again and you'll feel a less erupt turn. This mod along with working the areas around the guide mods have a huge impact on upward roof port flow.
    xs bowl 2.jpg
     
    TwoManyXS1Bs, gggGary and Jim like this.
  17. Jack

    Jack XS650 Junkie Top Contributor

    In this image I've done the mod, it's not as much as this image shows but its doesn't take much to yield a bigger gain. After you reinstall the guide and work the areas around the guide,you blend the area behind the arrows into the bowl. When the guide is installed and all casting flaws are cleaned up, I'll show and explain on working the guide boss how I do it.
    xs  bowl mod.jpg
     
  18. Jack

    Jack XS650 Junkie Top Contributor

    Theres a KZ porter who has a solid reputation among his KZ enthusiast who D ports all his KZs heads and won't do porting without the mod. A round concave port the mixture flow concentrates in the middle and a D port opens up the floor area wider spreading more air and fuel to utilize all of the short turn thus increasing volumetric efficiency,etc.
     
    Last edited: Dec 14, 2019
  19. Jack

    Jack XS650 Junkie Top Contributor

    Installed guide at 1.335 length, notice there's no protrusion in port.
    xs guide install.jpg
     

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