i hope i didnt ruin my engine

Discussion in 'Thumpers' started by mtn500, Sep 29, 2008.

  1. brucifer

    brucifer Long timer

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    Well, this probably isn't much help to you but a buddy of mine was way into these 500s several years ago and had tons of engine parts lying around. I know I've seen heads with and without the slots cut in them. It may have been a running production change Honda made to help oil the journals in the post '79 engines.
    If it was me putting this engine together, I certainly wouldn't be afraid of using the '79 head. Just keep the oil clean and full.
    #61
  2. brucifer

    brucifer Long timer

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    #62
  3. mtn500

    mtn500 bush jumper

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    Brucifer, thanks for your input and help. I saw the same with the other heads and figured the ones with no slots would be OK too, but I really wanted somebody else to have the same opinion/reasoning :D.

    I can't wait to get this girl back together and running. I've been going at it slow but I want to make sure that I do it right the first time.
    #63
  4. sieg

    sieg Wearing out tires......2 at a time, day after day.

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    I love these threads, it's amazing how much money and time you can save doing your own maintenance. :evil And hell this mechanic stuff is so simple anyone can do it! :deal<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
    #64
  5. mtn500

    mtn500 bush jumper

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    I am investigation the need for a set of ring expander pliers. As I have never installed new rings before can anyone comment on whether or not the ring expanders are necessary? Can the rings be CAREFULLY installed by hand or are the expanders highly recommended for installation?
    Thanks
    #65
  6. sieg

    sieg Wearing out tires......2 at a time, day after day.

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    Your fingers should suffice.:getiton<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
    #66
  7. mtn500

    mtn500 bush jumper

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    That is what I am thinking too as the rings are pretty thin. I'm probably just over thinking the whole process because I don' t want to mess it up. I've been told that the rings can be over expanded, and that makes sense but I figure if I very carefully do it...
    #67
  8. brucifer

    brucifer Long timer

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    Yeah, just take your time and be careful. If you have any questions on which rings go where or their orientation, just ask. Good luck. :thumb
    #68
  9. mtn500

    mtn500 bush jumper

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    Has anyone got any experience with replacing the exhaust stud bolts on the cylinder head? The studs would be at the 5 and 11 o'clock positions around the exhaust ports.[​IMG]

    My replacement head for this project did not have the studs when I received it. I ordered new studs to insert but the diameter of the end that screws into the cylinder head (end with fewer threads) seems to be too large. I have double checked that I ordered and received the correct part and verified that both the 79 ad 80 models used the same size studs. Using a caliper I measured the diameter of both ends of the studs; the end with fewer threads does have a slightly larger diameter. The stud(s) will start threading into the cylinder head but get really tight about half way in.
    [​IMG]
    I do not want to keep tightening and force them in and risk stripping the threads in the cylinder head. I've compared/referenced my old cylinder head and I am inserting them in the correct orientation. If i reverse orientation I can screw them in all the way with no problem, but hat is not how they are supposed to go.

    My clymer manual has limited info and does not indicate the correct torque to apply to these studs.

    Anyone know the correct amount of torque?
    Should they be this tight?
    Thoughts?

    Thanks
    #69
  10. brucifer

    brucifer Long timer

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    When you screw them in the other way, do they feel kinda loose or wiggly?

    I checked my Honda XR500 manual but it didn't say anything about those studs or the exhaust at all.

    I'm thinking that maybe the threads are an interference fit possibly, where the threads in the head are a little off to the threads on the stud for locking purposes--so the studs wouldn't come out with the nuts every time you loosened them. I could be way off on that though...
    Hopefully someone else will chime in.
    #70
  11. mtn500

    mtn500 bush jumper

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    brucifer, thanks for chiming in. When the threads are screwed in the other way they are just noticeably loose/wiggly all the way until all the threads are sunk and the smooth part of the stud is flush to the head.

    I have came across the interference fit theory and that makes sense. However, I don't want to push my luck, until I know for sure, and risk damaging this head.
    #71