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Cotten, I moved shovelhead operating temp here

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  • Cotten, I moved shovelhead operating temp here

    QUOTE=T. Cotten;192628]Let's think a bit, Ryan,..

    Even if its conjuring without any real numbers.

    The motor needs to warm up to a natural equilibrium to be efficient.
    It is ~eighty percent air-cooled, and perhaps at best ~twenty-percent oil-cooled, primarily by what oil exits.
    How cold must the incoming oil be to effectively cool the rest, without being so thick that it doesn't feed anyway?

    Surely all that restriction upon the exit helps, huh.

    ....Cotten[/QUOTE]

    I understand what you are saying, one surely would not want to put a huge cooler on it because the oil needs to be hot enough to burn out impurities and stay within the normal operating temperature, which is what I want to achieve. What is the normal operating temperature range for a generator Shovelhead?

    I am getting ready to run engine temperature tests as I eliminated all other possibilities of engine pinging. Burned out carbon in combustion chamber, cleaned and lubed distributor, timing with flywheel line in the center, added octane boost, running a colder plug, plugs read well for mixture. I cannot think of anything else but heat.

  • #2
    Not a harley guy so if Im missing something obvious,sorry.
    Arent their people who specialize in Harley timers similar to auto dist. shops?
    I sent my vintage auto dist. out for service after plotting the curve with a tack and timing light and confirming that it was way off.I realize this not an option for you.
    They plot the advance curve on a dist. machine and adjust advance curve to desired by changing or adjusting springs.
    My question would be what is my curve and what should it be.
    Tom

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    • #3
      I put my '65 timer on a Sun once, Tom!

      There was barely any curve at all, advancing almost instantaneously; Not really an 'auto-advance', but an 'auto-retard' when stopped.
      But it did diagnose my problem, with phantom fires all over the place: The points were bouncing!

      Back to coolers, Ryan,..
      I have no shovel data at all, just that they are a hundred degrees cooler than flatties, at the top end anyway.
      Its not hard to imagine the lower ends are similar.

      Please consider much of the return volume you will be cooling is air.

      ....Cotten
      Attached Files
      Last edited by T. Cotten; 09-09-2020, 10:11 AM.
      AMCA #776
      Dumpster Diver's Motto: Seek,... and Ye Shall Find!

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      • #4
        Thanks guys, just cannot seem to stop the bike from spark knocking and am at a loss on ideas.

        Comment


        • #5
          Originally posted by ryan View Post
          Thanks guys, just cannot seem to stop the bike from spark knocking and am at a loss on ideas.
          The first thing I would do, Ryan,..

          Is to strobe it to where the line is in the front of the hole, and see if anything improves.

          If its clacking away from stop signs before the tank is hot, no cooler is going to help.

          Do you know what pistons are in it? Can you give us a compression reading?

          ....Cotten
          Last edited by T. Cotten; 09-09-2020, 03:27 PM.
          AMCA #776
          Dumpster Diver's Motto: Seek,... and Ye Shall Find!

          Comment


          • #6
            Originally posted by T. Cotten View Post
            The first thing I would do, Ryan,..

            Is to strobe it to where the line is in the front of the hole, and see if anything improves.

            If its clacking away from stop signs before the tank is hot, no cooler is going to help.

            Do you know what pistons are in it? Can you give us a compression reading?

            ....Cotten
            Cotten,
            I tried static timing it with the line at the front of the hole and it would not start.
            I will check it with a strobe light where you ask. I do not know what kind of pistons are in the motor, but the build sheet says flh .010" pistons. I will do a compression test very soon.

            So what have I done wrong, I went by the book? I guess the book does state that static timing is a start point to get it running. I have owned this bike for 24 years and do not ever remember having this issue.

            Comment


            • #7
              Cotten, What about stick timing after I go through your list? Bob Rice suggested that he times his bikes when the front cylinder is 7/16 btdc.

              Comment


              • #8
                Because of "gear lash", Ryan,...

                Static timing is inherently retarded. That's why the early OHV manual (pg. 79) shows the mark at the very rear edge of the hole.
                If you static time to the front of the hole, its very "late".
                Dynamic timing with a strobe shows precisely when it is firing, and if you static time to the middle, most likely the strobe will show it forward.

                If you wish, you can put a degree wheel on your sprocket shaft, and set it by Top Dead Center, which is a lot easier than pulling a head to determine 7/16" before TDC. Then decide how much advance you want, turn the motor all the way through again to that stroke, stop where you decide, and set the timer.

                ....Cotten
                PS: I never encountered an HD mark that was wrong. Indians, yes.
                Attached Files
                Last edited by T. Cotten; 09-10-2020, 10:12 AM.
                AMCA #776
                Dumpster Diver's Motto: Seek,... and Ye Shall Find!

                Comment


                • #9
                  Originally posted by T. Cotten View Post
                  Because of "gear lash", Ryan,...

                  Static timing is inherently retarded. That's why the early OHV manual (pg. 79) shows the mark at the very rear edge of the hole.
                  If you static time to the front of the hole, its very "late".
                  Dynamic timing with a strobe shows precisely when it is firing, and if you static time to the middle, most likely the strobe will show it forward.

                  If you wish, you can put a degree wheel on your sprocket shaft, and set it by Top Dead Center, which is a lot easier than pulling a head to determine 7/16" before TDC.

                  ....Cotten
                  Cotten,
                  I would never pull my head off to measure 7/16" down from tdc, I thought about the degree wheel, but that is still a lot of work and only calculates moving the timing mark .060" toward the front of the window at the very top of the original timing line as it will not be paralleled with the original line. A strobe light it is, I do have the clear plastic plug to do so, check at about 2,000rpm?
                  Well I have some work to do this afternoon. I will strobe time it and do a compression test.
                  Thank you!
                  Last edited by ryan; 09-10-2020, 10:41 AM.

                  Comment


                  • #10
                    Memory fails, Folks,...

                    But wasn't it some 1961 productions that were missing one timing line for their dual-point ignitions?

                    I made a tool to gauge the piston position through the sparkplug hole.

                    The 14mm pilot appears lost...

                    ....Cotten
                    PS: Found it! It appears .545" is engraved upon the gauge. Does that sound right? Somehow it worked, but Shovels are probably a different angle.
                    Attached Files
                    Last edited by T. Cotten; 09-10-2020, 11:57 AM.
                    AMCA #776
                    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

                    Comment


                    • #11
                      Try putting new weights and springs in and then using a timing light to time it at 2000 rpm. Those weights wear out often.

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                      • #12
                        Originally posted by 1937hd View Post
                        Try putting new weights and springs in and then using a timing light to time it at 2000 rpm. Those weights wear out often.
                        Been trying to find nos items with no luck. I did check the pins and weights for wear and there was no wear on either, cleaned and lubed with light weight synthetic grease. The springs return great with very little tension. That's all I can do for now to the timer.
                        I will stobe time it tomorrow at roughly 2000 rpm. Oh, I can hook up a tach, I have one for my bike, but opted for the cigarette lighter instead.

                        Comment


                        • #13
                          Thinking out loud here, perhaps the Servi-Car weights and springs are set up for a slower advance due to the needs of the bike, and those needs somewhat mimic a sidecar tug...
                          And simple compression plates under the cylinders could help with the ping.

                          On a manual advance timer the rider can control the advance curve which I find quite handy in traffic or steep grades on my sidecar rig.
                          Robbie Knight Amca #2736

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                          • #14
                            Hopefully I can get it with the strobe light, if not the servicar weights and springs.
                            How would I use a manual timer without the mounting at the block for the timer cable? Is there an adapter plate or would I have to fashion one? Boy !this is turning into some work.
                            I do not have this much trouble with my hopped up 289 hipo with the same total timing of 35 and 2.5 points up higher on compression.

                            Comment


                            • #15
                              Originally posted by T. Cotten View Post
                              The first thing I would do, Ryan,..

                              Is to strobe it to where the line is in the front of the hole, and see if anything improves.

                              If its clacking away from stop signs before the tank is hot, no cooler is going to help.

                              Do you know what pistons are in it? Can you give us a compression reading?

                              ....Cotten
                              Ok, Compression testing: cyl one is 65 initial push and 143 psi Cylinder two initial push is 65 and 145 psi. This was tested on a warmed up engine.

                              So my compression ratio is almost 10:1 (145/14.7=9.8)

                              I just strobe timed is and going on a test ride.

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