Marelli Points | FerrariChat

Marelli Points

Discussion in 'Technical Q&A' started by racerboy9, Oct 8, 2018.

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  1. racerboy9

    racerboy9 F1 Rookie
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    Nov 3, 2003
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    #1 racerboy9, Oct 8, 2018
    I am having a hell of a time installing my NOS Marelli points in my Dino 246 3-lobe distributor. The fiber block is so tight on the shaft. I got one of them on but it doesn't rotate on the shaft with the spring tension. I have to move it with long nose pliers. I took a points plate off a spare distributor so I could play with it out of the distributor housing but again it seems awfully tight. I decided to halt my efforts till I get some Ferrarichat advice. Is there a trick to this I am missing?
     
  2. phil99

    phil99 Rookie

    Feb 26, 2015
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    Phil S.
    #2 phil99, Oct 8, 2018
    I have just changed the points on my 3-lobe Dino distributor (Fiat Dino, but same distributor) and it was straightforward although fiddly. Any chance you could post a picture of what is going on?
    Thanks,
    Phil
     
  3. racerboy9

    racerboy9 F1 Rookie
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    #3 racerboy9, Oct 8, 2018
    Here is the problem. Seems like too tight a fit. I could file the fiber part but that seems like a bad idea. Could go from too tight to too loose.
     

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  4. racerboy9

    racerboy9 F1 Rookie
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    #4 racerboy9, Oct 8, 2018
    I could put some fine valve grinding paste on the shaft and work the point block back and forth but that may be a bad idea as well.
     
  5. Motob

    Motob Formula 3
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    Nov 11, 2003
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    Brian Brown
    #5 Motob, Oct 8, 2018
    This is standard on original Marelli points. You must have a 6mm reamer so you can ream the inside bore to have nice precise fit on the shaft. I would not use valve grinding compound, as it will embed itself into the soft phenolic block and end up wearing out the points faster than normal.
    You can purchase reproduction points as they have a loose fit on the shaft or get a 6mm hand reamer.
    https://www.amazon.com/6mm-Straight-Shank-Hand-Reamer/dp/B008ED5GW2
     
  6. racerboy9

    racerboy9 F1 Rookie
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    #6 racerboy9, Oct 9, 2018
    Thanks for this tip. The reamer looks like a good bet. You would think Marelli would have got it right at the factory!
     
  7. Motob

    Motob Formula 3
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    Brian Brown
    #7 Motob, Oct 9, 2018
    It wasn't that Marelli got it wrong. Reaming the points to have a perfect fit was considered a regular part of servicing the distributor.
     
  8. markcF355

    markcF355 F1 Rookie
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    #8 markcF355, Oct 12, 2018
    Isn't this all really pointless?

    Sorry.
     
  9. 335s

    335s Formula Junior

    Jan 17, 2007
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    T. Monma
    #9 335s, Oct 17, 2018
    Use a "B" drill as I recall, on the phenolic part of points which pivot on the post(this IS the problem from the sounds of it), and the fit will be perfect....this is a fairly common problem with old NOS parts-not a big/rare deal...
     

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