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'47 UL manifold leak fix

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  • '47 UL manifold leak fix

    MAP_4012_5633 (2).jpgMAP_4011_5632 (2).jpg
    This thread started on 11th July when I discovered that my ’47 UL wasn’t running right. Poor performance and spark plugs that were a different colour were the symptoms.
    Folks on this site suggested I had a manifold air leak
    It took me while to build a manifold leak test tool but the diagnosis of manifold air leak proved spot on. Unfortunately when I came to remove the manifold nut to the rear cylinder (where the leak was) it became clear that the intake nipple was also loose and would need replacing. See follow up post of 14th September.
    Having asked about the task on the forum it was clear that this was not going to be a simple job and I viewed the prospect with some trepidation. In fact my first thought was to get some professional help. In the end I went ahead myself reasoning that so long as I did nothing that would damage the cylinder any mistake could be rectified.
    With acknowledgement to those on this forum (especially Cotton and Big Lake Bob) for their tips and advice this is how I got on. I hope it assist others in the same position:
    The problem I had was that the old nipple had not been set properly. The locating rivet hole had obviously worn oversize and a non standard brass rivet inserted from the outside of the cylinder and just peened over to seal the hole. Looked at from the inside of the intake the rivet was clearly loose and hence the nipple was free to move if any pressure was exerted on it such as when loosening the manifold nut. Once I had ground off the peened end I was able to knock out the old rivet without difficulty.
    I did not try and unscrew the nipple from the cylinder. It felt as though it would have come right out but followed the advice that this might damage the internal threads. Instead I (very) carefully ground through the old nipple with a Dremel and diamond tipped bit. It was tedious but worth the effort. The old nipple eventually fell out and the intake internal threads remained undamaged and actually seemed in good shape.
    I had secured a new Colony nipple and a packet of locating rivets
    I used JB weld High Steel to build up the internal diameter of the rivet locating hole in the side of the cylinder. I just worked it in a little at a time until I could just about push the new pin through and it was a good tight fit at both ends. This was especially tricky on the inside diameter of the intake as I didn’t want to get the JB weld on the threads. I kept screwing the new nipple in and out as I worked to ensure that the threads were kept clear.
    I had a number of options for sealant. JB weld epoxy, Permatex and Gasoil were all recommended as provided the necessary seal but being resistant to gas. I felt the epoxy would create a permanent join and didn’t really want that. In the end I opted for the Permatex. The sealant was applied and the new nipple located onto the cylinder threads and tightened down.
    I used a drill press to insert a bit through the hole on the side of the cylinder and drill through the new nipple. I used a slightly smaller bit than the diameter of the rivet and then gently reamed it out until the rivet could just be inserted but remained a good tight fit. I then smothered the hole and new rivet with more Permatex and finally located it in position.
    In order to lock the rivet in place to enable the top to be peened I used a length of 1 ¼ inch round steel bar. The internal diameter of the nipple is a little larger but when you account for the rivet head as well I just needed to grind a flat spot to the end of the bar before it would slide in and lock the bottom of the rivet in place.
    While this was being done I had sent my manifold to Mullie Motors in Amsterdam to have new peek seals fitted. They did a great job.
    When back together I pressure tested the manifold again. All seemed air tight.
    I got the bike back on the road last weekend and just had a shake down ride of maybe 5 or 6 miles to make sure everything was ok.
    When the engine had cooled I pulled the plugs again. See the photos attached to this thread. The carb had not been adjusted at all since the shots posted in July although next time I take the bike out I will lean it out one notch.
    It has taken me while to get this job done but I only get a few hours each weekend to work on the bike. On this occasion I think it was a good thing. This is not a job that can be hurried (not for me at least) and the delays enabled me to think through and plan each step and what I would need by way of tools, parts etc.

    Martin

  • #2
    So Martin!

    Now that you have persevere'd, and succeeded due entirely to your own patience and observation of detail, and some resourcefulness,....

    How much would you expect an honestly-professional service shop to charge, if they accepted it at all....?

    Thanks in advance, of course..

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

    Comment


    • #3
      Cotton,

      The best answer I can give is to estimate the time it took me.

      Leaving aside that I had to take off the head and barrel and then put them back on again and that while they were off I took the opportunity to de coke the intake chamber and the top of the piston. The intake valve wasn't in great shape either due to the heat of running too lean so I also gave the valves a gentle lapping before putting it back together.

      Building the manifold leak testing tool took a while as well but that was a one off.

      Also doing anything for the first time takes longer.

      I wasn't keeping a close watch on the clock being far more concerned to get the job done right. My best estimate is that just the replacement of the nipple itself took around 5 hours.
      or so. Parts and materials were not too bad. I found the Colony nipple fitted well as did the rivets they supplied

      How much it would cost would depend on the hourly rate your engineering shop wanted to charge. There are maybe a couple of people in the UK I would have entrusted this job to. Would they have taken it on? Who knows.

      In the end, and despite some anxious moments along the way, I was pleased that I decided to do the job myself. Most of all I have the satisfaction of knowing exactly what has been done and how.

      Thanks again for steering me down the path

      Martin

      Comment


      • #4
        Martin!

        Its a tedious chore no doubt!
        Even though I have developed a shelf of dedicated tooling to simplify it, my shop is still not ready to offer the service except to established accounts. There is no way we could charge ~$300 plus parts without somebody displeased sooner or later!

        Most folks are like you, and find satisfaction in overcoming these obstacles, and realize that it is part of the romance and adventure of owning a piece of History.
        But many are not so resourceful, so I have been encouraging others in the industry to specialize in this operation.

        So far, they are all too smart to stick their neck out!

        ....Cotten
        PS: Colony rivets (along with any O-ring) are tossed into my 'raw materials' bins without a second thought.
        AMCA #776
        Dumpster Diver's Motto: Seek,... and Ye Shall Find!

        Comment


        • #5
          Hi Martin,
          where abouts in the UK are you?
          Regards
          Tony

          Comment


          • #6
            Tony,

            I'm in Bristol. I see your in Hampshire - Whereabouts? What bike/s do you have?

            Cheers

            Martin

            Comment


            • #7
              Originally posted by Martin Pettingell View Post
              Tony,

              I'm in Bristol. I see your in Hampshire - Whereabouts? What bike/s do you have?

              Cheers

              Martin
              Gday Martin,

              I'm in between Chichester and Portsmouth.

              My pride and joy is 1974 Ironhead sporty, had it since 1999 and she's a keeper but my goal is to get a VL as I just love them.
              One day!!
              Take care

              Tony

              Comment


              • #8
                Tony,

                Great bike. Love the old iron heads.

                As for VL's - you probably know this anyway - but a good start is Steve Slocombe's (of VL Heaven) book on the subject. At least you will know what to be looking for when the time comes. He's no so far from your neck of the woods either.

                Cheers

                Martin

                Comment


                • #9
                  Originally posted by Martin Pettingell View Post
                  Tony,

                  Great bike. Love the old iron heads.

                  As for VL's - you probably know this anyway - but a good start is Steve Slocombe's (of VL Heaven) book on the subject. At least you will know what to be looking for when the time comes. He's no so far from your neck of the woods either.

                  Cheers

                  Martin
                  Thanks Martin,
                  I do already own Steves book which I don't know is a good thing because its like slow torture reading it haha.

                  Is there any pics of your bike's on the site I can look up?

                  Cheers

                  Tony

                  Comment


                  • #10
                    Martin,
                    Good job! - Changing those nipples is always a tedious procedure. Unfortunately, it looks like I'll need to change those on my knucklehead, as I used a set with the O-Rings which was a mistake given the available gasoline and the sun exposure. While I haven't done any diagnosis yet, the motor doesn't return to idle as quickly as it should which is a classic intake leak symptom. I'm curious - did you use No.2 Permatex as a sealing agent?
                    Thanks....
                    Bill Pedalino
                    Huntington, New York
                    AMCA 6755

                    Comment


                    • #11
                      Bill
                      It was Permatex - the right stuff , that I used. I recall it being recommended in something I had read on the issue.
                      It has 'one minute gasket' on the container
                      I used it as it seemed to set to a strong but not permanent bond and it was suggested that it will resist gas - I guess time will tell on that
                      Martin

                      Comment


                      • #12
                        Martin/Cotton,
                        Can you recommend a source for the correct rivets? I'll probably use new Colony inserts and, as Tom Cotton recommends, discard the O-Rings and rivets.
                        Thanks and Merry Christmas,
                        Bill
                        Bill Pedalino
                        Huntington, New York
                        AMCA 6755

                        Comment


                        • #13
                          Bill!

                          Even if you found "correct" NOS rivets, they probably would not be appropriate.

                          Nearly always the hole for the rivet must be reamed 'clean', and an appropriate rivet custom-cut to a sweet, light-press fit.
                          In addition, it takes enormous pressure to force a rivet with a flat-bottomed head to conform and seal to the curved inside surface of the nipple, risking the brittle casting around it.
                          As I discussed at http://virtualindian.org/11techleaktest.html, a conical head is self-sealing. With an appropriate anvil, it can be pressed outward, and a simple smack on the outside will swell its barrel, and upset the end to secure it.

                          For rivet material, I would cut them from much larger rivets. My sources have dried up, as dumpster picking never recovered from the Recession.

                          ....Cotten
                          PS: Happy Holidays Everyone!
                          Attached Files
                          Last edited by T. Cotten; 12-24-2015, 02:23 PM.
                          AMCA #776
                          Dumpster Diver's Motto: Seek,... and Ye Shall Find!

                          Comment


                          • #14
                            Cotten,
                            Did you turn down that tapered rivet from steel stock? The geometry of that rivet head looks like it would seal the inside edge of the nipple hole quite nicely.
                            After leak testing using a copy of your leak fixture, I found a substantial leak at the rear nipple near between the manifold nut and the casting, adjacent to the the rivet hole. I haven't removed the head form the bike yet but with the manifold off and the existing rivet tapped out, it looks (??) like there might be a small crack in the head between the rivet hole and the edge of the casting where the nipple threads in. As we're all aware, there isn't that much meat in this area in the first place. I'm not sure at this point as I must now remove the head and extract the nipple to take a closer look, If there is a crack I'm going to have to do some head-scratching as this is not an easy repair! Maybe as our friend in the UK did, some JB Metal filler in in the casting hole and tight-fitting rivet through the insert lieu of a complicated welding/machining process? Not sure until I can really see what's going on.
                            Bill Pedalino
                            Huntington, New York
                            AMCA 6755

                            Comment


                            • #15
                              Bill!

                              I scrounge large nails from.... well you know...

                              ....Cotten
                              PS: The dumpsters are not the horn'o'plenty that they were before the 'crash of '08'.
                              Anyone who boasts of a "recovery" after seven long, hard, years 'speaks with forked tongue'.
                              There are still six empty businesses on my city block, and perhaps more soon.
                              Last edited by T. Cotten; 02-27-2016, 12:49 PM.
                              AMCA #776
                              Dumpster Diver's Motto: Seek,... and Ye Shall Find!

                              Comment

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