Anyone ever tried putting a oil in the bottom of a China Girl Motor crankcase?

Discussion in 'Motorized Bicycle General Discussion' started by Nashville Kat, Aug 6, 2013.

  1. Nashville Kat

    Nashville Kat Active Member

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    Just wondering what a small 1/4" or so pool of oil might do at the bottom of a china girl? Maybe just below the seal line, that could slosh around a bit on the bottom end parts, a bit like a 4 stroker.

    anyone ever tried it?

    If it didn't affect the performance, maybe it would extend the life of the bottom end.

    zpt
     
  2. tooljunkie

    tooljunkie Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    would be extremely harmful to the performance of the motor.the fuel/oil mix goes from carb and through crankcase on its way to the cylinder,with oil in there,the gas would pick it up and basically flood the cylinder with enough oil it wouldnt run.

    some of the two stroke marine engines actually have tubes that draw the puddling fuel.
     
  3. crassius

    crassius Well-Known Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    yep, just coating over-liberally with oil when assembling an engine will leave you smoking a LOT for several minutes
     
  4. Nashville Kat

    Nashville Kat Active Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    "would be extremely harmful to the performance of the motor.the fuel/oil mix goes from carb and through crankcase on its way to the cylinder,with oil in there,the gas would pick it up and basically flood the cylinder with enough oil it wouldnt run"

    Well, you might be right, but I think the fuel mixture actually is just marginally allowed into the crankcase from the carb, through the lesser two ports, and for the purpose of lubricating the bottom end. The main thrust is into the cylinder and then through the exhaust port
     
  5. Arnold Layne

    Arnold Layne New Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    Tool IS right, anything in the bottom end will be swept up as fuel, in this case, really oily fuel.
     
  6. maniac57

    maniac57 Old, Fat, and still faster than you

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    The crankcase is part of the induction, any oil in there will be pulled into the jug and burned very quickly.
    Nice idea but will not affect engine life.
     
  7. 2door

    2door Moderator
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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    It won't stay there long so any benefit, if any, would be short lived.

    Tom
     
  8. Greg58

    Greg58 Well-Known Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    It probably would smoke like a train for a bit too.
     
  9. xseler

    xseler Well-Known Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    Just had a flashback to my '74 Vega..........it was smoke'n!!
     
  10. Huffydavidson

    Huffydavidson STREETRACER/MANUFACTURER

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    Got a light? trying to smoke some 90 wt.
     
  11. KenX

    KenX New Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    Agree with this statement.
     
  12. Nashville Kat

    Nashville Kat Active Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    Why don't you just invent us some Valves then, Oline?

    We're putting the BAND back together"
    several of them actually, gRUNT.
     
  13. bairdco

    bairdco a guy who makes cool bikes

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    it goes against the principals of a two stroke engine. the reason you add oil to the fuel is so the oil lubricates the moving parts, which is why two strokes don't have oil pans. a four stroke doesn't get washed with the fuel/oil mixture and has seperate compartments. one to lube the internals and one containing the fuel/air charge.

    adding oil to the crankcase of a two stroke would be the same as running an extremely rich fuel/oil mixture, only worse, because you're dumping the pre-mixed fuel and oil into a pure oil bath.

    if it ran at all, the oil would be burnt up immediately, or just flushed out the exhaust port, resulting in a clogged up pipe and an oily mess.

    trying to add an external oil pan wouldn't work either, because the mechanics of a two stroke uses the mixture and the charged piston to circulate everything through all the engine components. you'd have to isolate the crankcase from the oil, and then you'd have a four stroke.

    make sense now?
     
  14. mapbike

    mapbike Active Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    How could it be said any better......right on.......!.wee.
     
  15. 2door

    2door Moderator
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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    I'm wondering why nobody has thought to ask how you plan to get the oil in the crankcase in the first place.

    Tom
     
  16. RicksRides

    RicksRides New Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    Dang 2door you beat me to it!
    Nash, if youre that worried about lubrication: Use a good synthetic 2 stroke oil and instead of running 50 or 100;1 run it at what ever ratio your motor calls for. shouldn't cause any harm
    Rick
     
    #16 RicksRides, Aug 10, 2013
    Last edited: Aug 10, 2013
  17. KCvale

    KCvale Well-Known Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    It helps to know how the engine you are using actually works.

    If you look in to the cylinder intake hole you will see it does not go directly into it, everything goes down into the crankcase and then back up into the cylinder on the side.

    [​IMG]

    Heck most of time a bike with spark won't start is because the crankcrase is full of crap and simply pulling the plug and not giving it any gas and pedaling it up and down the street will blow all that crap out and it fire right up.
     
  18. mapbike

    mapbike Active Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    Tom,
    Actually that is the easiest part of the whole thing..... you just drill a 11.3 Millimeter hole through the case preferably right through one of the transfer port passages, stick the end of the oil filled squirt can in the hole and give it about 23-38 good squirts of 40W non-Detergent China Lube Snake Oil, then when you're done, clean it real good with Ching Pow brand Fingernail polish remover to get all the oil off the surface around the 11.3mm hole, then you will want to plug up the hole with a healthy amount of bright red Metric J-B Weld, the SAE stuff just wont stick to the Chinese Aluminum.

    See, it's really quite simple when you have the right tools and understand how all of this works.

    Map
    dance1
     
  19. Nashville Kat

    Nashville Kat Active Member

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    I've been sitting here with a jug and an old piston in my hand-

    yes, your comments are right, and the flaw in my own thinking was that the top of the piston cleared the intake port- but it never does-

    yes, all of the intake is drawn in a roundabout way through the slots at the bottom of the piston and not at the top- the bottom of the piston clears the intake port, but the side slots in the bottom of the piston clear the side ports only at the very top of the piston stroke.

    It appears that the piston never really clears the exhaust port at any time, top or bottom, so that all of the exhaust exits through a side port and then goes to the exhaust port through the jug.
     
    #19 Nashville Kat, Aug 10, 2013
    Last edited: Aug 10, 2013
  20. maniac57

    maniac57 Old, Fat, and still faster than you

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    Re: Anyone ever tried putting a pool of oil in the bottom of a China Girl crankcase?

    The best thing you can do for your bottom end is keep the revs reasonable, and don't lean it out too much. Running it slightly rich keeps the bearings lubed as well as the cylinder.
     

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