512 BB carb | FerrariChat

512 BB carb

Discussion in 'Boxers/TR/M' started by turbo-joe, Sep 2, 2020.

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  1. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    8,918
    southwest germany and thailand
    Full Name:
    romano schwabel
    hello all
    after long time waiting for parts and also because of covid 19 stranded in thailand for additional 3 month I nearly finished with my BB with the major and also new clutch. let it run today and wondered about the sound from the ignition box. as I remember there was always a wining and now this wining is nearly not to hear anymore.

    is this a good sign or a bad sign?

    only like top be prepaired

    thank you to the BB specialists
     
  2. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    8,918
    southwest germany and thailand
    Full Name:
    romano schwabel
    no one knows???
     
  3. DonB

    DonB Formula Junior
    BANNED

    Nov 11, 2003
    616
    Florida
    Full Name:
    Don Bartz
    Hi Joe..

    The sound from the ignition box is from a diode. I'm not too sure about the sound level vs longevity question. When mine failed on my BBi it was making the sound just fine..only problem is the car wouldn't start!

    I, like so many others installed a MSD unit to replace the Mirelli unit. Then it failed....the tell tale on it was the Tach started being erratic. It would work then die, then work etc.

    I replaced the MSD with a new Pertronix unit. Both the MSD and the Pertronix wire up the same so the change out was no big deal. The Pertronix is about 1/3 the size of the MSD and has more flexibility and adjustments.

    A suggestion here. If you decide to change out the Marelli unit may I suggest wiring it like this: You can purchase the connectors used by Ferrari on line on eBay. I suggest you wire the connection out of either the MSD or Pertronix so that no change is made to the "pig tail" coming out of the car's chassis. It's a pretty easy job and works well. I think there are links on here showing the wiring diagrams too.

    Good luck!
     
  4. samsaprunoff

    samsaprunoff F1 Rookie
    Silver Subscribed

    Jun 8, 2004
    4,178
    Edmonton, AB Canada
    Full Name:
    Sam Saprunoff
    Good day Romano,

    The sound you hear is typically caused by the internal electronics causing very small (minute) vibrations in some components (inductors) that we ultimately hear. Consequently, hearing the sound or not hearing the sound cannot be used as a definite test and/or indicator of your ignition module's state of health. That being said, if you are using the original Ignition module I would replace or upgrade the unit, as it is a matter of time before they fail. The original Marelli modules had design flaws that really made it sensitive to input voltage fluctuations which would cause the module to fail... usually at the most inconvenient times.

    Cheers,

    Sam
     
    pshoejberg likes this.
  5. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    8,918
    southwest germany and thailand
    Full Name:
    romano schwabel
    thank you don and sam for the comments

    I thaught because of this wining we can say if the ignition is just before going dead or still ok?

    what type of pertronix you use don?
    you can still use then the original coil with the 3 connectors or need an other coil? what about the distributor pick up?

    had a look at the german pertronix side but there is not much standing
     
  6. ago car nut

    ago car nut F1 Veteran
    Silver Subscribed

    Aug 29, 2008
    5,265
    Madison Ohio
    Full Name:
    David A.
    Current MSD box, not like in the past for quality!
     
  7. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    8,918
    southwest germany and thailand
    Full Name:
    romano schwabel
    thanks david, but I asked don because he has written he has in now the pertronix
     
  8. samsaprunoff

    samsaprunoff F1 Rookie
    Silver Subscribed

    Jun 8, 2004
    4,178
    Edmonton, AB Canada
    Full Name:
    Sam Saprunoff
    Good day Romano,

    In the past most (including me) most used the MSD 6A module (https://www.holley.com/products/ignition/ignition_boxes/street/parts/6201). This unit requires some slight wiring changes and a new base plate made in order to match up to the original Marelli module's mounting studs. My first MSD unit lasted for about 5 years and then started to act up and so I replaced it. Reviewing some past reviews on the Internet, it seems that MSD's quality control is not as good as it was and so a number of people have been having similar issues.

    As for Pertronix...I have recently been working with the "Pertronix Digital HP" module (https://pertronixbrands.com/pages/pertronix-ignition-ignition-boxes) and it is very impressive. It is smaller than the MSD unit and allows one to embed the module into the original Marelli module if one is so inclined. This unit also allows for field programmability of the module and so it can be tailored as needed:

    ..Number of Cylinders
    ..Trigger Type (points or electronic pickup)
    ..Fatal Rev Limit
    ..Launch Rev Limit
    ..Burnout Rev Limit
    ..Shift Light On
    ..Shift Light Off
    ..Multi-Spark
    ..Power Level (in mJ)
    ..Start Retard Degrees
    ..Start Retard RPM

    The module also has a tachometer calibration mode which generates a Tach signal so you can verify that your tach reads what it is supposed to. Overall a very impressive unit and far more capable than the MSD unit. I will be replacing my MSD unit with this Pertronix unit within the original Marelli housing so that it all looks OEM.

    Cheers,

    Sam
     
    375+ likes this.
  9. DonB

    DonB Formula Junior
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    Nov 11, 2003
    616
    Florida
    Full Name:
    Don Bartz
    That answers just about all I can think of..plus I used the stock coil.

    I think it's important to take note of the capability of multi-spark or non multi-spark with the Pertronix unit. A point was brought up previously that the multi-spark feature (MSD and Pertronix) increases the heat load/ionization inside of the distributor cap leading to premature failure. With all those contacts and the tight space maybe that is a real factor?

    I've vented my distributor (not the cap) to allow for a little more air flow through it...and how does one measure that flow? I don't know..if you find out let me know :)

    It's also been said that the MSD and Pertronix produce the same Jules (sp?) of spark that the factory Marelli unit produced. FWIW..

    All I know is my Pertronix works just fine and is "hidden" in a highly secret location somewhere deep within the bowels of my car.. Why it's so secret I forgot where it is....
     
    turbo-joe likes this.

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