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Thread: Oil pumps, sumping, burnishing/reseating ball seat

  1. #1
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    Default Oil pumps, sumping, burnishing/reseating ball seat

    47 knucklehead, lots of corrosion on ball seat has caused loss of 3-4 qts of oil in a 2 week period on a fresh bike build. New springs and balls used as well. So I used a chemical called Kreteclean from a company called EDPI. The solution cut back sumping by brush application as well as q tip application.to a pint every 3-4 days so some success was had.

    Prior, I tried to burnish the seat but no success.

    Looked online and found this:
    http://www.precisionballs.com/ball_valve.php

    Has anyone tried their #3 & #6 - 3/8" tool for refreshing the pumps seat?
    Last edited by ricmoran; 03-07-2018 at 11:28 AM.

  2. #2
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    Ric!

    I haven't tried their tool, but,...

    After bench-testing seats with bubbles,
    I found that because often the threads in the pump bodies are not concentric to the seats,
    and some bodies were chilled too hard for a cutter, and even damaged ball bearing burnishers.

    So only a flat grind from the top to remove damage greatly improved things, and any further treatment of any sort (piloted cutting, angle grinding, lapping, burnishing, or beating with a drift..) only made it worse.

    ....Cotten
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    Last edited by T. Cotten; 03-07-2018 at 11:46 AM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  3. #3
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    Chemical rust removing removes the scale but does not clean the pits. TO get a square cut a floating tool such as the 3/8" diamond tool would most likely not get a concentric cut. I was concerened about that and though that maybe drilling the pumps screw cover over the valve (have extras) for the polishers shaft stability might help. The tools manufacturer cautions against hi rpm tools and recommends a slow turning tool to drive the tool.

    At this point, the pump is not healthy at all as no resolve means too much oil loss over time. Might continue on with chemical rust remover but concern exccessive oil loss from pits. So after more rust remover time will gauge loss.

    Las Vegas time could be coming, lol.
    Last edited by ricmoran; 03-07-2018 at 03:57 PM.

  4. #4
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    Ric!

    My best guess is the original factory seat was just a smaller hole drilled into a larger counterbored hole, with one fixturing.
    The threads for the cap were added in a separate machine operation, producing a concentricity error that the Factory could care less about.

    If you are grinding a flat surface, ninety degrees to the bore, concentricity to the seat drops out of the equation.

    Just diamond-dress a common airgrinder stone to fit into the bore with a perfectly flat end on it.
    Then pilot it through a piece o' bolt or something.

    .....Cotten
    PS: Folks,
    I have studied this problem for decades, once even throwing teflon balls at it.
    The MOCO figured you would run it often enough to purge the sump.
    "Often enough" is aggravated by decades of wear.

    So either ride it often, or drain the tank.
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    Last edited by T. Cotten; 03-07-2018 at 05:57 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  5. #5
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    From what I could see inside the ball valves galley way, it looks like the seating material is shaped like a short funnel the extrudes into the galleyway from the wall of of the pump, both inside and out. Maybe its my messed up vision but this image shows that the seat area is quite narrow and over polishing it ould seem to make the opening wider from seat shoulder to seat shoulder. Tried to attach an image but file size is too large.

  6. #6
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    So either ride it often, or drain the tank.[/QUOTE]

    Leave it running, lol. Yes, both are an option and so is hunting for a better conditioned pump. I have a thought that after 7 decades it might be like trying to findout a needle in a haystack.

    Any idea how well the repro V Twin oil pump performs?

  7. #7
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    Quote Originally Posted by ricmoran View Post
    From what I could see inside the ball valves galley way, it looks like the seating material is shaped like a short funnel the extrudes into the galleyway from the wall of of the pump, both inside and out. Maybe its my messed up vision but this image shows that the seat area is quite narrow and over polishing it ould seem to make the opening wider from seat shoulder to seat shoulder. Tried to attach an image but file size is too large.
    Ric!

    I have an arthroscope for inspection, but only large defects are obvious. (So I rely on bubbles.)

    Your instincts are correct that a wide seat is not better.
    (Its not like a motor valve that must conduct its heat.)

    If you would like to email me your pic at liberty@npoint.net, I can quickly re-size it and return it to you, or post it here if you wish.
    (Or open it on your PC by right-clicking and then choosing "Open with" and then "Paint". Up at the left you will see "resize". Just cut your pixels in half and see if it will upload.)

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

  8. #8
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    Tom, was thinking of attempting the repair and sending you the 2 diamond impregnated grinders to see what results you get with them. Will send image to your email address.

  9. #9
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    Whoa Ric!

    I haven't accepted any new motorwork accounts in over fifteen years; A test would be unlikely.

    Considering how much time, effort, resources, and money I have lost studying this problem, I prefer to let others take over.

    But my opinion is always available,

    ....Cotten
    Last edited by T. Cotten; 03-09-2018 at 05:01 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  10. #10
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    Ok, will try it out and advise what happens. Cutting back in work is a good thing tho. Do you still do peek seals on manifolds yet?

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