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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. Signal

    Signal XS650 Junkie Top Contributor

    Jack , thank you for what you have shown us. I would find it helpful if you were able to post a photo of the valve opening method you use when flow testing.
    Hope you have a good day on the bench.
     
    Bewarethemoon, Jim, spungle and 2 others like this.
  2. Jack

    Jack XS650 Junkie Top Contributor

    Will take photos and record the best I can :thumbsup:
     
  3. Signal

    Signal XS650 Junkie Top Contributor

  4. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Some pictures of you guys while flow testing!
     
  5. Jack

    Jack XS650 Junkie Top Contributor

    OK there's bad news and VERY VERY goods . Bad news is due to Atlantas congested traffic jams and accidents I arrived late and wasn't able to
    correct any port CFM differences,it was getting very late and was just so fatigued from the dive and running around trying to squeeze everything in with
    what little time we had left. On the right port there are apparently some minor differences in the short turn radius and bowl along the long side. I'm
    in the process of making molds of the good port for comparison,will make adjustments and then it's back to Dallas for more flow testing .
    Good news is the left port excelled above my expectations and the contributors would be the valves, seat work and the port with absolutely no
    resistance,none,real smooth running port and the #s back this up. In comparison to the first D port flowed, 100 lift picked up 13.5 CFM,200 lift picked
    up 18.5 CFM,300 lift picked up 21CFM,400 lift picked up 15.5 CFM,Wasn't able to flow higher than 400 cuz stupid me took the wrong spring retainers.
    Although I wasn't able to bias max flow at 300 lift,I was able to bring max flow at 400 lift down to 300 lift and still managed to increase flow at 400.
    Waiting for the molds to harden so I can get back to working the right port. Took a view videos but am lost has how to up load from phone.
     
    TwoManyXS1Bs, Mailman, Signal and 5 others like this.
  6. Jack

    Jack XS650 Junkie Top Contributor

    Here's the head on the bench d port flowing.jpg
     
    Mailman, Signal, spungle and 4 others like this.
  7. Jack

    Jack XS650 Junkie Top Contributor

    Head was warped,had to mill 0.005 off to clean up surface
    milled xs head.jpg
     
    Mailman, spungle, grizld1 and 4 others like this.
  8. Jack

    Jack XS650 Junkie Top Contributor

    First head I ported, the ported exhaust #s shot through the roof and were a rare exception when having material a port to work with and I came close.
    one other time to matching theses #s. Look at the gains not the #s 1l flows2.jpg
     
    TwoManyXS1Bs, Mailman, Signal and 6 others like this.
  9. Jack

    Jack XS650 Junkie Top Contributor

    First D port
    intake
    100 lift-83
    200 lift-114
    300 lift-137
    400 lift 184
    430 lift 187

    Exhaust
    79
    106
    126
    140
    142
     
    Signal, spungle, grizld1 and 3 others like this.
  10. Jack

    Jack XS650 Junkie Top Contributor

    Second D port
    91
    132
    170
    185
    198
    Exhaust are the same as first d port
    Now with reworking the area in front of guide and the boss cuz I added epoxy to the roof and guide boss
    80
    119
    181
    201
    205
     
    Signal, spungle, grizld1 and 3 others like this.
  11. Jack

    Jack XS650 Junkie Top Contributor

    Now here's Chris's head
    Left port and right port down 1,12,18,18 CFM
    100 lift-93.60
    200 lift-137.52
    300 lift-202.35
    400 lift-216.50
    Exhaust
    100 lift-91.77
    200 lift-119.14
    300 lift-132.02
    400 lift-143.29
     
    spungle, arcticXS, grizld1 and 4 others like this.
  12. Jack

    Jack XS650 Junkie Top Contributor

  13. grizld1

    grizld1 Grumpy old man Top Contributor

  14. Jim

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

  15. Jack

    Jack XS650 Junkie Top Contributor

    JIm,have no idea whats going,I can click links and video plays. Can't seem to up load the other video
     
    spungle and Jim like this.
  16. spungle

    spungle XS650 Member

    Unfortunately I have extremely little time this week, a lot to do at work and with the family... Dear Jack, what a bummer the ride was so turbulent. I am glad that the head has come out so good!

    Can you please explain what you mean with:
    Is the handwritten chart you postet above of your first ported head and taken with the same flow bench? And was it also an DPort?

    I can´t see a file in your link. If you like you can send me the video via https://wetransfer.com/, I will put it here!

    Aller beste Grüße and a big thx!
     
    Last edited: Jan 17, 2020
    Bewarethemoon and Jim like this.
  17. Jack

    Jack XS650 Junkie Top Contributor

    The right port was down on flow, the port dimensions are with in spec but I overlooked a small hump at the inner bottom corner of the wall near the short turn, which I filed down, lowered the corners of the short turn just a hair more and slightly rolled them over plus worked the guide boss some more. Also worked the long side of the bowl leading up to the seat smoothing the transition by straightening it out a hair more These small imperfections can upset flow by slowing it down and it doesn't take much to speed air flow back up. Will be going back down to Dallas next Saturday to re-flow the head, hopefully it'll be a positive test.
    All the heads where flowed on the same bench and no the first one was not a D port
     
    grizld1, spungle, ReycleBill and 4 others like this.
  18. spungle

    spungle XS650 Member

    Thanks for clarifying, interpreting english language is sometimes not so easy for me:)
    If I see it right, the flow in the lower and middle lift areas has gone up till a plus of 40cfm at 300 lift! (in compare to the stock head as your old chart says)
    And in my understanding the low lift gains benifits not only in the lower till middle rpm range but over the hole rpm range, and so I could have a torque monster:love: (by way of reference to an usually XS;)

    Also, the E/I ratio is usually well over or near 70%. I have read that everything over 60% is good, 70% plus = high performance, 80% plus = top racing. So I like it very much and it promises more torque in the lower and middle range, if the other components play along (and i try as best as i can to catch this) nice :cheers::rock:

    And last but not least I must say wow, you optimesed the E Ports to a very fine plus over the hole lift range.(in compare to the stock head as your old chart says). I think optimising the E Port to such extend is awesome!

    cfm stock I:
    lift - I cfm - E cfm - E/I flow ratio

    100 - 76 - 67 - 88%
    200 - 118 - 96 - 81%
    300 - 162 - 115 - 71%
    400 - 181 - 122 - 67%
    440 - 190 - 121 - 64%

    work in progress head
    :
    lift - I cfm - E cfm - E/I flow ratio
    100 - 93,6 - 91,7 - 98,0%
    200 - 137,5 - 119 - 86,6%
    300 - 202,3 - 132 - 65,2%
    400 - 216,5- 143 - 66,1%
    440 - with the right retainers - next weekend:whistle:


    In anticipation of the coming weekend:D I wish you that this time the journey goes well!:bike:

    p.s. what did you do with your first modified head, that the exhaust have such great gains? Did you test wise epoxied it up, or was it voodo magic?


     
    Last edited: Jan 20, 2020
  19. Jack

    Jack XS650 Junkie Top Contributor

    spungle
    Jack
    If I see it right, the flow in the lower and middle lift areas has gone up till a plus of 40cfm at 300 lift! (in compare to the stock head as your old chart says)
    And in my understanding the low lift gains benifits not only in the lower till middle rpm range but over the hole rpm range, and so I could have a torque monster:love: (by way of reference to an usually XS;)
    Yes having stronger low to mid flow will produce more power in that area of the flow curve but the over all bigger picture is that every time the valve events opening and closing the port is moving more air in total than a port with peak numbers and what this achieves is a torque curve that hangs on longer producing more peak power. The flow curve of this D port was a total surprise for sure as I wasn't expecting that much of a flow shift in the 300 lift range and 400 lift range disrupting the targeted flow ratio I was after. Depending on how the right port flows,I might have to make some flow changes to the left port to level out the cylinder pressures.

    Also, the E/I ratio is usually well over or near 70%. I have read that everything over 60% is good, 70% plus = high performance, 80% plus = top racing. So I like it very much and it promises more torque in the lower and middle range, if the other components play along (and i try as best as i can to catch this) nice :cheers::rock:
    Don't to get to fixated on flow ratios and flow numbers,it all depends on the engine combination and yours being a long rod,this changes some what do to pumping loses through the ports. The numbers will change by drag loses through the carb,manifold,air filter and air quality. Exhaust changes with exhaust system. On a long rod motor you want very high velocity,high flowing ports to over come the pumping loses from TDC to 90 degree stroke and at BDC as the piston dwells it allows the flow inertia to pack the cylinders tighter.


    And last but not least I must say wow, you optimesed the E Ports to a very fine plus over the hole lift range.(in compare to the stock head as your old chart says). I think optimising the E Port to such extend is awesome!
    You have to be careful not to over scavenge,the 100 to 200 lift range still eludes me,one day I'll get it.


    cfm stock I:
    lift - I cfm - E cfm - E/I flow ratio

    100 - 76 - 67 - 88%
    200 - 118 - 96 - 81%
    300 - 162 - 115 - 71%
    400 - 181 - 122 - 67%
    440 - 190 - 121 - 64%

    work in progress head
    :
    lift - I cfm - E cfm - E/I flow ratio
    100 - 93,6 - 91,7 - 98,0%
    200 - 137,5 - 119 - 86,6%
    300 - 202,3 - 132 - 65,2%
    400 - 216,5- 143 - 66,1%
    440 - with the right retainers - next weekend:whistle:

    :D There might be some more flow in that lift.
    In anticipation of the coming weekend:D I wish you that this time the journey goes well!:bike:

    p.s. what did you do with your first modified head, that the exhaust have such great gains? Did you test wise epoxied it up, or was it voodo magic?
    It was all "FINGER VOODOO" and very hard to duplicate how i twisted the inner port
    wall and roof,it has to be dead nuts correct to reduce the flow resistance as it turns.
     
    Last edited by a moderator: Jan 21, 2020
    TwoManyXS1Bs, ReycleBill, Jim and 3 others like this.
  20. spungle

    spungle XS650 Member

    Thumbs crossed this time all went well! Please let us see a video from your benchwork:thumbsup:
     
    ReycleBill, Bewarethemoon and Jim like this.

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