flow results abf head

Discussion in '16-valve' started by smarte00, Jan 14, 2009.

  1. Brookster

    Brookster Paid Member Paid Member

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  2. possle Forum Member

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    wicked more searching to do!
    Anyway back to head flows etc!
     
  3. mr hillclimber Club GTI Supporter and Sponsor

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    I spose I could pull my finger out and connect up the velocity probe (my bench can support this) and measure velocity for you chaps as well.... cuh, you dont want much!

    Though I'm quite sure velocity is'nt falling, if it is it wont be much, I dont make the ports that big, and dont touch the area prior to the split at all.
     
  4. mr hillclimber Club GTI Supporter and Sponsor

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    Dont the DTH bodies mask the injector scoop? I've got some in the unit but not to hand.

    My DCOE 16v manifold does just that. I did consider adding a lump to fill the scoop but left it due to extra cost for little gain. With the manifold covering the face of the scoop, flow goes up when fitted to a standard, so there maybe an increase in velocity going on.

    It's not a great deal of difference in terms of flow between an XE and our 16v. In standard form, both heads make around 110cfm, with the XE on a 1mm bigger valve. When ported, a good XE makes 142cfm on the inlet, my best so far is 137cfm from VW 16v, still with standard valves, so 1mm smaller than the XE.

    The XE, and many other 16'v have a much better combustion chamber design, the VW is poor, sort of half a pent roof, half a bathtub design.

    The XE also has better exhaust flow, and much bigger bores, so starts to stride away.
     
  5. mr hillclimber Club GTI Supporter and Sponsor

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    Nope, no differance at all Neal. I really must connect up the pitot tube though!

    I recently did a manifold for a Guernsey hillclimb MK1, so the injector scoops were covered but not filled. It made std 16v power and torque low down up to around 4.5k, the head (not mine, just a fast roady) 276 cams, 45's all coming into play there upwards. Even on a short primary 4-1 manifold and std c.r it didnt lack low end.

    I feel as long as the cut outs are masked, which a decent manifold will/should do, they can just be left out of the picture.

    Brian's fill-in's could be handy for those using a poor manifold design.
     
  6. possle Forum Member

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    top man. Will put some minds at ease!
     
  7. badger5

    badger5 Club GTI Sponsor and Supporter Trader

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    they do mask it yes, but i always wondered about some back tumble from that area as velocity increases past that crevice

    there has to be a significant velocity difference from xe to valver with the port size diferences - flow being the same
     
  8. mr hillclimber Club GTI Supporter and Sponsor

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    It's certainly possible.

    At some point I'll do flow & velocity test on an XE to see the difference.

    I would have expected to see a flow difference though if there was a great amount of turbulance caused by the scoop.... though the small flow increase I see when fitting one of my manifolds maybe telling us something.
     
    Last edited: Oct 31, 2010
  9. Brian.G

    Brian.G Forum Member

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    Id imagine in any case it would improve Intake reversion turbulence in that area. Possibly nothing to worry about, but I worry about stuff sometimes. A port can never be too streamlined I feel.
     
  10. possle Forum Member

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    Did anymore results come about?
    What would this likely do the hurt performance.
    **** it off if ya want! i know its a bad job! first time just dived in! Its not finshed but i done think il get any gains after reading this thread

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  11. Brookster

    Brookster Paid Member Paid Member

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    Reversion is a major issue when running on gas , one reason why i would like one Brian. :thumbup:
     
  12. R.b!n_16v Forum Member

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    bump^^ for extra develpments
     
  13. mr hillclimber Club GTI Supporter and Sponsor

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    coming soon...
     

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