Page 2 of 2 FirstFirst 12
Results 11 to 19 of 19

Thread: Cotten ! - linkert differences

  1. #11
    Join Date
    Mar 2017
    Posts
    141

    Default

    Thank you Cotton for the lesson on how the carb chokes work.

    I could not dream of welding inside the bore or barrel of a carb. be
    There is always a low area around the weld no matter how you not to get one. Now building up a broken ear would be a different story. The guy "Tatro" I was watching soldering up the barrels ended up boring and opening up the barrels way to large, I would think, leaving about .005" clearance between the barrel and the venturi. How would the carb work well after that? I am pretty sure over sized venturis are not available or you would not be soldering the barrels up.

    Anyway, too many questions with not enough time.
    Thanks again Cotton, greatly appreciated!

  2. #12
    Join Date
    Aug 2004
    Location
    Beautiful Northern New Mexico
    Posts
    2,192

    Default

    Ryan, just cut a new oversize venturi. Not difficult to do.
    Robbie Knight Amca #2736

  3. #13
    Join Date
    Jun 2001
    Location
    Central Illinois, USA
    Posts
    3,313

    Default

    Ryan!

    I routinely swage potmetal venturies oversize, and lathe-cut them to a light press fit for oversized bores.
    (Ironically, after months, they shrink again to a slip fit, but they stay round. A 'bombsight" probably couldn't be swaged.)

    This is far more economical than scratch cutting, as it only takes twenty minutes compared to over an hour, no aluminum billet, and saves the original that otherwise would be useless.

    They can be brittle from "zinc pest" however, and no two are the same, so its more art than science.
    When one cannot be saved, its still cheaper to swage a Colony venturi than scratch-cut.

    If your borewear is minimal, just a fresh Colony may suffice.

    ....Cotten
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  4. #14
    Join Date
    Jan 2005
    Location
    Vancouver Island B.C.
    Posts
    430

    Default

    I'm familiar with swaging boiler tubes in a tube sheet of a fire tube boiler and tubes in a shell and tube heat exchanger...but how does one swage a venturi in a carb body? That's a new one on me.

  5. #15
    Join Date
    Jun 2001
    Location
    Central Illinois, USA
    Posts
    3,313

    Default

    Quote Originally Posted by cdndewey View Post
    I'm familiar with swaging boiler tubes in a tube sheet of a fire tube boiler and tubes in a shell and tube heat exchanger...but how does one swage a venturi in a carb body? That's a new one on me.
    Carefully, Dewey, carefully!

    As I described, it is not swaged in the body, but outside, and then lathe-cut to fit.
    I have carved a selection of fitted cones for a screw press. Models and vintages vary in technique. There are critical tricks of course, and pitfalls to watch out for, but I must keep my cards close to my chest.
    Everybody should enjoy as many failures as I have.

    .....Cotten
    PS: A little common sense goes a long ways: If it looks like the one in the attachment, don't ruin the "History".
    Attached Images Attached Images
    Last edited by T. Cotten; 06-06-2017 at 10:32 AM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  6. #16
    Join Date
    Jun 2010
    Posts
    181

    Default

    Cottten !
    I have three carbs, id=1.560
    I have three venturi, od=1.557
    Clearance=.003"
    I can swage or machine but I think the factory made them this way.
    What say ye ?


  7. #17
    Join Date
    Jun 2001
    Location
    Central Illinois, USA
    Posts
    3,313

    Default

    1950Panhead!

    I still believe they were a slip-fit originally, with very little daylight visible around them.
    But they shrank and distorted.

    And beware that Colony's first productions were copies of shrunken examples. (Lately they've been pretty decent..)

    If you can see daylight around them, it defeats the 'accelerator' function of the main nozzle.
    (And they can rattle and wear against the nozzle spigot.)

    Since I hone borewear from virtually every body, I swage virtually every venturi, even new productions.
    (Unless its something weird I must cut from scratch..)

    ....Cotten
    Attached Images Attached Images
    Last edited by T. Cotten; 06-28-2017 at 03:33 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  8. #18
    Join Date
    Jun 2010
    Posts
    181

    Default

    Cotten !
    Your photo has a big gap, like .025"
    You cannot see light with .003"
    Colony sells .025" over, I will machine to finger press.
    Thanks for posting.

  9. #19
    Join Date
    Jun 2001
    Location
    Central Illinois, USA
    Posts
    3,313

    Default

    Actually, 1950Panhead,

    The gap was only about five thou, the light for the camera accents it.

    Here's one of Colony's first productions; it looks larger than a few thou as well.
    (Colony corrected, and I use their products regularly..)

    Still, no daylight is acceptible if you want all the performance possible. This is only one of the reasons why Linkerts have gotten a bad rap in modern times.

    ....Cotten
    PS: Many folks think that just because there is a little drag through the bore that nothing is wrong.
    Attached Images Attached Images
    Last edited by T. Cotten; 06-29-2017 at 02:05 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •