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V12 with two 6 lobe distributors, points gap

Discussion in 'Vintage (thru 365 GTC4)' started by Peter Lipman, Dec 30, 2021.

  1. Peter Lipman

    Peter Lipman Rookie

    Nov 24, 2020
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    Peter Lipman
    i have a later V12 365GT 2+2 that has two 6 lobe distributors. all of the manuals i have relate to the 3 lobe distributors and indicate that the standard points gap should be set to .014. the gap on the current points is more in the .009-.010 range, which makes sense since more dwell is needed with 6 lobes. does anyone know what the standard points gap should be with a 6 lobe distributor on V12?
     
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  3. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
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    so the 6 lobe distributor has then each only 1 point or also 2 points inside? with 2 points then also 0,4 mm is ok.
    until now I only have seen 3 lobe and 4 lobe distributors in a ferrari
    only at lamborghini I have seen 6 lobe

    a single V 12 distributor with 4 points has the same same gap, 0,4 mm

    only when you have 1 point inside each
     
  4. Peter Lipman

    Peter Lipman Rookie

    Nov 24, 2020
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    it has a second set of points but they are only for an emission control function that reduces dwell at idle. i have that second set of points disabled and the car runs great. so this is really a single set of points and 6 lobes.
     
  5. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
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    you are sure?
    when it reduces dwell ( angle ) at idle then it also reduces the dwell (angle ) at high rpm, and there it is more important than at idle to have a long closing dwell ( angle )
    so the 2nd set of point you disconnected now where was this connected to? sorry, I can not imagine how this would work

    here is a simple point ignition for a 4 cylinder with only 1 set of points
    Image Unavailable, Please Login
     
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  6. turbo-joe

    turbo-joe F1 Veteran

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    how you connect then the 2nd set of points when those are only for idle?
     
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  8. Peter Lipman

    Peter Lipman Rookie

    Nov 24, 2020
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    i am running these distributors as 6 lobe single points per lobe. the second set of points is disconnected and is not needed. I am just trying to determine the proper gap. i have found some information that suggests that the dwell angle should be 20 degrees and so i may use that info to set the gap.
     
  9. kare

    kare F1 Rookie
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    Nov 11, 2003
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    I always thought the 2nd set of points (in case they are clearly off-set) was used to increase advance on idle as Italians rarely installed a vacuum advance on a performance engine. By my experience vacuum advance may save upto 35% fuel in city traffic, so it most certainly affects emissions as well.
     
  10. turbo-joe

    turbo-joe F1 Veteran

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    and how are those second points connected?
     
  11. DWR46

    DWR46 Formula 3
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    Jun 19, 2012
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    Peter: Factory spec on the six lobe distributor engines is .012-.015" point gap. I would aim for .014-.015". This gap will not give any point bounce to over 7,500 engine rpm. Make sure you are using the "four spring" points.
     
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  13. kare

    kare F1 Rookie
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    Nov 11, 2003
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    Some european cars I've seen just have a provision for a second set, I always thought they may have been used for US-market cars to pass emission testing.
     
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  14. DWR46

    DWR46 Formula 3
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    Jun 19, 2012
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    Kare: The "second" set of points was triggered by a microswitch on the throttle linkage. They switched the ignition over to retarded timing at idle for emissions. Most owners and shops either disconnected them or removed them. The cars run fine on a single set of points using a six lobe cam.
     
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  15. Peter Lipman

    Peter Lipman Rookie

    Nov 24, 2020
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    that is my situation and i think i am ok with the points gap too.
     
  16. Peter Lipman

    Peter Lipman Rookie

    Nov 24, 2020
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    I am all set with the points gap. another question. I am refreshing everything and ordered new capacitors as well. the ones i was sent are a Marelli CE36E which is marked as .25 uF rather than the .18 uF that I was expecting. What is your opinion about that difference?
     
  17. turbo-joe

    turbo-joe F1 Veteran

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    no problem I would say
     
  18. DWR46

    DWR46 Formula 3
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    Peter: The .18mfd capacitor is correct for your car. For many years, the correct rating and style unit has not been available from Marelli to my knowledge. If your points are not showing excessive pitting, and you currently have .18mfd units, leave them alone. Capacitors rarely go bad. In the past, shops replaced them primarily to sell parts and as insurance the car would continue to run well. The main purpose of the capacitor is to reduce point pitting and the second purpose is to match the coil inductance for best spark. The car will run pretty well with the .25mfd units, but if it was running well before, NO reason to switch out the correct capacitors for the wrong ones. If you want to replace them, in the 1970s, most General Motors cars used .18mfd capacitors. Search out some of those units. It has been YEARS since I replaced capacitors on a Ferrari.
     
  19. JimEakin

    JimEakin Formula Junior
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    Jun 13, 2015
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    It’s been documented here on FChat and the web that condensers from some manufacturers have poorly assembled internal connections, so be sure to check how the condenser you use was made.

    Also, be sure to clean the lobes then lightly apply fresh lube or grease to the lobes. If not, the points could wear down in about 500 miles.
     
  20. turbo-joe

    turbo-joe F1 Veteran

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    that is why some distributors have inside a "brush" what have to be oiled a little
     
  21. JimEakin

    JimEakin Formula Junior
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    Right. I applied a small amount of lube just “upstream” of the brush, using a q-tip,
     
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