Broken Off Channel Opening Where Cylinder Head Screw Goes Through

Discussion in 'Airheads' started by jpbellavance, May 28, 2013.

  1. jpbellavance

    jpbellavance Adventurer

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    I recently bought a 1986 R65 BMW. When I went to adjust the valves I noticed that the previous owner had done a fix to his right cylinder head nut channel so that I assume oil would not leak out of it. It was basically a high heat type of gummy substance that would not detoriate and allow oil to pass through the channel.

    I wanted to replace the gaskets on the cylinder head and this gummy stuff had to come off. The question I have is what type of gummy stuff do you think was used to create the seal. Or what should I use to create another temporary seal.

    Or are there other solutions out there I could try without buying a whole new cylinder body?

    Thanks in advance for any help. Attached is a pic of what I have to work with.
    [​IMG]
    #1
  2. Big Bamboo

    Big Bamboo Aircooled & Sunbaked

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    I would try using a copper washer and self locking nut on the stud first.
    #2
  3. Airhead Wrangler

    Airhead Wrangler Long timer

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    get someone to build up aluminum again with a welder. It wouldn't take long at all to build it up and file and then sand it flat again.
    #3
  4. jpbellavance

    jpbellavance Adventurer

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    Would this create a seal? If so how? Thanks. I like this idea but was hoping you could elaborate on it a bit.

    Thanks,
    JPB
    #4
  5. disston

    disston ShadeTreeExpert

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    The welded with Aluminum is the best idea. There are a number of fair welders around that can do this but maybe more volunteers than those capable. Try to get a reference. I really think you might get it done cheaper than you think but you are going to have to do the filing part and it will require a pretty large quality file to do right.

    In lieu of the quality Aluminum repair, how are you with forming epoxy? This would work too.
    #5
  6. oldroadie

    oldroadie Two wheel addict

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    JB Weld. I do it again. Which is basically what disston said but omitted the brand name.
    #6
  7. Velocipede

    Velocipede Been here awhile

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    If it was my bike I'd have it welded then re-faced.If you aren't confident enough to use a file to clean the face have a machine shop do it,shouldn't be too expensive.
    If you dont want to go that route you could use J-B Weld,many have fixed bigger problems with it.I prefer the stick over the epoxy.

    John
    #7
  8. Plaka

    Plaka Brevis illi vita est

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    That doesn't lake any pressure so there is a quick easy repair that will last forever.

    First get the gummy stuff off and completely clean and roughen the metal. A small ball cutter in a dremel will work well, just go over the area with the ball exposing fresh metal.

    Now you need a bolt that will go through the head, a pair of regular washers, a fender washer and some wax. Wax up the shank of the bolt and the fender washer. Two coats with drying in-between. Then you need some JB weld. Plenty strong and good adhesion. Mix it up and apply to the area so it's nice and high everywhere. Now put a washer on the waxed bolt, then the waxed fender washer and stuff it in from the outside, then another washer and the nut. Tighten the nut hand tight---just enough to get that fender washer seated on the head surface with no JB weld between it and the good sealing surface.

    let it harden well then pop out the bolt and washers. You will have molded a new sealing surface that matches the existing. Clean up as needed and It's done.
    #8
  9. ozmoses

    ozmoses Ride On

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    My /7 came with that situation repaired w/ JBweld. I've had it for several years w/ no issues. No idea how long it was repaired before my tenure but, based on the general lack of maintenance, probably quite a while.
    #9
  10. jpbellavance

    jpbellavance Adventurer

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    Thanks all for the great suggestions! I will let you know how it all works out. Again. Thanks!

    JPB
    #10
  11. Pokie

    Pokie Just plain Pokie.

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    If you're just looking for opinions,...... leave it alone.

    If it leaks oil on the back side, fit a fiber washer under the nut and washer. You will be able to ride it for miles and miles even years and years without any trouble. The next time the heads are off for a re-build, have the head welded and re-surfaced. Until then, it's not hurting a thing.
    #11
  12. Kai Ju

    Kai Ju Long timer

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    Pokie's solution is the simplest and likely will work just fine with the fiber washer sealing the oil in.
    Should you choose Plaka's method make darn sure that none of the aluminum ends up in your valvetrain to be washed into the engine through the pushrod tubes.
    #12
  13. Plaka

    Plaka Brevis illi vita est

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    I'd pull the rockers and pushrods, stuff the holes then flush very well after the epoxy work and any final grinding or filing..especially around the springs.
    #13