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Journal Bearing Steel Epoxy Repair?

  1. Jul 10, 2011 #1
    A camshaft journal bearing was damaged due to oil starvation.
    after camshaft is replaced.

    Using a proper epoxy resin to fill in the damaged / pitted journal surface then honing the journal back to the standard size.

    After that adding groves or small pits that would work as oil pockets increase the chances of this journal bearing to work?

    I know most damage to the bearing is done during startup of engine, wouldn't having those groves or oil pockets protect the journal surface from contacting the camshaft and hence keeping it from getting damaged?

    any input would help, thank you!
     
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  3. Jul 11, 2011 #2

    Mech_Engineer

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    No epoxy will have the wear resistance or hardness necessary to function as a journal bearing. I think it's time to buy a new camshaft, sorry.
     
  4. Jul 11, 2011 #3
    "A camshaft journal bearing"
    Is the camshaft damaged itself??
    If not replace the bearing. If so how bad and can it be turned to save the shaft??
    Such as shaft repair will also necessitate new bearings to the right size.
     
  5. Jul 11, 2011 #4
    the epoxy will be applied to the journal bearing not the camshaft.
    the camshaft is new.

    the camshaft floats on a thin oil film that surrounds it, technically the only contact that happens is only during start up, and having tiny oil pockets will act as a lubricant during start up reducing wear. when the engine is running the camshaft never touches the surface of the bearing.


    oh and the bearing is not removable, its a part of the cylinder head that was milled out.
     
  6. Jul 12, 2011 #5
    How many other journals are there?

    I've seen a guy who, when faced with a single galled journal on a toyota overhead cam engine, just ground the recess out such that it did not touch the camshaft at all since the cam had at 5 other bearings.

    Then he plugged the oil gallery opening on that bearing.

    I expected the cam to eventually break but that car came back for regular maintenance running fine for at least 2 years........not that you should try this yourself.

    What is the model of engine?
     
  7. Jul 12, 2011 #6
    only one bad journal, but its the one closest to the timing belt. also the biggest one.
    there are i think four more.

    that's a good idea but I think it might not work since this is the last journal and it would put a lot of stress on the camshaft

    its a 2002 freelander 2.5 kv6

    garbagetiest engine ever made
     
  8. Jul 12, 2011 #7

    Q_Goest

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    Could you bore out the journal and sleeve it, say with a bronze bushing or similar? If you can't find a bushing off the shelf with the right dimensions, you might make your own.
     
  9. Jul 12, 2011 #8
    that was actually my first solution to the problem, sadly I can't find a bushing the size i need, getting one made would be far too expensive. and I don't have the tools to make one my own :(

    there is another solution which is actually the most correct way to do it and its to weld the gauges and scrapes then re-hone the bearing... sadly again i don't have the right tools.


    I might in the end have to buy another cylinder head :(
     
  10. Jul 12, 2011 #9

    Q_Goest

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    What diameters do you have and what length of journal? I suspect there's something 'off the shelf' that would fit. Have you looked?

    I would guess that having one made is going to run $50 to $100, give or take. If I had to have one made I'd make up a sketch (include tolerances and make it look semi-professional) and go out to a few machine shops in the area and get some quotes. Some won't touch it because there's not enough money in it, but I suspect you can find a shop that likes helping people out like yourself and will give you a fair price.
     
  11. Jul 13, 2011 #10
    great idea.

    I looked over the shelf and couldn't find the right size, since I need to hone the damaged areas and I can hone only so much. hence I'm judged by the depth of damage and not a standard bearing depth.

    I could get one machines, except I also need to hone the journal and that will cost me another $100 - $150 since I don't have the tools.

    eventually I think I'd be better off buying a used cylinder head...

    I really wanted to save this head, but there's no way I can tell if the epoxy filling will stand the pressure. I can't afford to put everything back together only for it to go bad the first 5 minutes of running haha!

    new head it is... sadly
     
  12. Jul 13, 2011 #11

    AlephZero

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    It won't. And sorting out the collateral damage from bits of epoxy getting into places they aren't supposed to be (oilways, valve guides, piston rings, etc) might cost you a lot more than a "conventional" fix for the problem.
     
  13. Jul 13, 2011 #12
    Now that we know it's the bearing closest to the cam gear, we can deduce it is a critical bearing and under far more force than the rest.

    Unless it's a cylinder for a sohc ford 427, a boss 429, or a rare ferrari, I would believe it should be replacable.
     
  14. Jul 13, 2011 #13

    brewnog

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    In order of preference, replace the head, repair it properly (proper machine shop job), or buy a new engine. Don't mess about with epoxy on critical features like bearings.
     
  15. Jul 13, 2011 #14
    Thank you so much for the help people, I was really in a pickle for this one but you really confirmed all my doubts, I don't know where i would be without your advice!
     
  16. Jul 14, 2011 #15

    brewnog

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    At the side of the road, waiting for the recovery waggon probably.
     
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