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Thread: Cotten, I moved shovelhead operating temp here

  1. #1
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    Default 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. #2
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    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

  3. #3
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    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
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    Last edited by T. Cotten; 09-09-2020 at 10:11 AM.
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  4. #4
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    Thanks guys, just cannot seem to stop the bike from spark knocking and am at a loss on ideas.

  5. #5
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    Quote 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 at 03:27 PM.
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  6. #6
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    Quote 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.

  7. #7
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    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.

  8. #8
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    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.
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    Last edited by T. Cotten; 09-10-2020 at 10:12 AM.
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  9. #9
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    Quote 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 at 10:41 AM.

  10. #10
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    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.
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    Last edited by T. Cotten; 09-10-2020 at 11:57 AM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

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