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Converting from mag to electronic

  1. May 19, 2006 #1

    wolram

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    Ok magnetoes are fine buit expensive to keep in A1 condition, so i want to convert to electronic, i have the means to manufacture the body to hold the new mechanism, and guess i can tailor it to fit some prop trigger mechanism
    for the LT, the problem is a control for maping the required advance/retard,
    i am quite niffty with a soldering iron, so i think i could build the electronics,
    but how do i go about maping it to the engine?
     
  2. jcsd
  3. May 19, 2006 #2

    wolram

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    This is for a single cylinder engine
     
  4. May 19, 2006 #3
    Any expanded Blue Prints of the Engine?

    Model:
    Type:
    Year:
    Spects:
     
  5. May 19, 2006 #4

    FredGarvin

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    So you're first hurdle would be to get some kind of cam sensor to dictate the firing...right? It's been a while since I have dealt with this stuff. For a single cylinder, is it really that beneficial to give yourself a lead/retard on the firing?
     
  6. May 19, 2006 #5

    wolram

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    It sure is for cold starting Fred, and performance of course, i have several ways i could go,manual advance /retard mag, Points/coil, electronic.
    If i can find an electronic pick up i can make an adapter housing drive shaft ect, the electronics seem simple, apart from the advance/retard, i think i need some sort of feed back to the circuit ie engine rpm but that could come from the pick up i think, or maybe i could buy a (black box) off the shelf,
    all very much up in the air at the minute, i could buy a ready made convertion but that comes to 500 UK+.
     
  7. May 19, 2006 #6

    FredGarvin

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    You would have to vary the advance/retard based on throttle position as well as engine RPM I would think. Back when I worked in automotive powertrain, I remember quite a few parameters were involved in the calculations the engine PCM would do to adjust it. I think that RPM would be the bare minimum if your load increases steadily with RPM. If not, I think you'd have to work in throttle position as well.
     
  8. May 19, 2006 #7

    wolram

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  9. May 19, 2006 #8

    wolram

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    This site is akin to what i will
    try to make, it seems all i need for the trigger is an hall effect sensor, this could be possitioned to pick up on some rotating
    engine part, i think i will need an rpm sensor (trigger) and a electronic vacuum sensor for best results.

    http://www.realclassic.co.uk/techfiles/tech03061700.html

    Mapping the curve is still the headache, this site says 1 degree per 100 rpm
    for this bike.

    The multi spark option ie the plug fires several times sounds good .
     
  10. May 19, 2006 #9

    FredGarvin

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    I know cam sensors are indeed hall effect sensors on larger engines.

    I'm gonna have to do some reading here.
     
  11. May 20, 2006 #10

    wolram

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    Sorry Intuitive i missed this post.

    Model: velocette
    Type: MAC
    Year: 1960
    cc: 349
    Compression ratio: 6.75 to one
    Carburetter: 15/16 Amal
    Electrics: 6v
     
  12. May 20, 2006 #11
    Ah yes, a Velocette, have your tried posting this on the "Brit Bike Forum"?
    Cheers,
    RG500
     
  13. May 20, 2006 #12
    Hi Wolram.

    What's the Stator count on your Magneto?

    I have seen ones with 4 Stators and some up to 10 Stators on the Stator Ring.

    Are you using a rebuilt original Magneto or are you using a Modern cross referenced Magneto?
     
  14. May 20, 2006 #13

    wolram

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    It looks like the original mag, i have asked around, and it seems the auto
    advance on these lucas type kif mags have always had problems, the auto advance is type jy16a, and most tend to fit a mag with manual advance.

    I have not taken the mag apart, as after reading 10s of peoples problems
    with this mag, i decided it would be best to go electronic.
     
  15. May 20, 2006 #14

    wolram

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    I just spent an enjoyable hour on that forum, great place RG500:smile:
     
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