275 GTS ignition wiring | FerrariChat

275 GTS ignition wiring

Discussion in 'Vintage (thru 365 GTC4)' started by ISBC90T, Oct 9, 2014.

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  1. ISBC90T

    ISBC90T Rookie

    May 16, 2007
    30
    Smalltown USA.
    I have a 1965 275 GTS in the shop. The points have been replaced with an electronic ignition and the coils are now blue Bosch without ballast resistors. The factory wiring diagram clearly shows resistors in the coil wiring circuits.

    Did the stock factory setup use Magneti Marelli coils with the square resistors mounted to the coil brackets? The coils are mounted to the distributors and the condensers have been removed.

    I can't find a engine bay picture anywhere legible enough to discern what the stock setup was. Thanks.
     
  2. DWR46

    DWR46 Formula 3
    Honorary

    Jun 19, 2012
    2,038
    Original factory ignition used Marelli BZR201A Coils, Square Resistors, and CE1E Condensers.
     
  3. ISBC90T

    ISBC90T Rookie

    May 16, 2007
    30
    Smalltown USA.
    Thank you for the info.

    I mounted two original coils and coil brackets to the distributor studs. No room now for the square resistors to mount on the coil brackets. I'm stuck...
     
  4. ISBC90T

    ISBC90T Rookie

    May 16, 2007
    30
    Smalltown USA.
    Do the ignition coils and resistors mount to the distributor housings or is there a separate bracket they mount to?
     
  5. DWR46

    DWR46 Formula 3
    Honorary

    Jun 19, 2012
    2,038
    They mount to studs off the distributor housings.
     
  6. ISBC90T

    ISBC90T Rookie

    May 16, 2007
    30
    Smalltown USA.
    We have the coil/resistor assembly mounted to the driver side distributor using both of the mounting studs.

    The problem now is the only way to fit the coil/resistor to the passenger side, is to use the rear slot of the coil mounting bracket onto the front stud on the distributor.
    Just doesn't seem how the factory would have done it. All suggestions at this point are welcome and much appreciated.
     
  7. Motob

    Motob Formula 3
    Professional Ferrari Technician

    Nov 11, 2003
    2,365
    Frederick, Maryland
    Full Name:
    Brian Brown
    Some 275's have no clearance between the ballast resistors if both coil mounting brackets have the mounts for the resistors both on the front. Ferrari modified one of the coil mounting brackets so that the resistor mounts on the side of the coil. Send me an email at [email protected], and I can send you photos of what the bracket should look like. It is an easy modification. My PM box is full and ferrarichat will not let me post any more photos.

    Brian Brown
    Patrick Ottis Co.
     
  8. DWR46

    DWR46 Formula 3
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    Jun 19, 2012
    2,038
    #8 DWR46, Oct 23, 2014
    Last edited by a moderator: Sep 7, 2017
  9. TTR

    TTR F1 Veteran
    Rossa Subscribed

    Mar 29, 2007
    5,890
    Riverside, CA
    Full Name:
    Timo
    Brian, hopefully I'm not stating obvious, but I think there's an option to delete/empty PM boxes, though it might require $15.00/year membership fee, which should also allow one to post pictures. Perhaps mods can clarify this ?
     
  10. buurman

    buurman Formula Junior

    Sep 21, 2004
    267
    Full Name:
    cornelis leendert

    Emperor and kings don´t know what pocket money is.
    People like Brian B. can elevate this side strongly.
    but Rob L. don´t seams to know what he is offering
    the vintage technical side here is simply poor -except Dyke-, better go to TY.
    Not eveybody like to be a moderator or honery status person.

    C.
     
  11. ISBC90T

    ISBC90T Rookie

    May 16, 2007
    30
    Smalltown USA.
    #11 ISBC90T, Oct 23, 2014
    Last edited: Oct 23, 2014
    DWR46 - THANK YOU for the pictures!!!

    I'm seeing a bracket coming off of the timing hold down stud. I'm missing that bracket. Great pictures!!! You just made my day.

    Brian, this is a different car than you helped me with before. I just sent you a freind request on FB.
     
  12. Motob

    Motob Formula 3
    Professional Ferrari Technician

    Nov 11, 2003
    2,365
    Frederick, Maryland
    Full Name:
    Brian Brown
    Not all 275's are the same. Some used the brackets that mount to the distributor mounting studs as shown on the photos that DWR46 posted, but these are fairly rare. I have only seen these on 275's with very low engine numbers. These parts are not even shown in the 275GTB/GTS parts book.
    What is the chassis/engine number of your car DWR46? Do your angle drive have the bosses cast into the sides for the studs? They will be cast into both sides of each distributor angle drive with only one side drilled and tapped for the coil mounting brackets.
    What is the chassis/engine number of your car ISBC90T?
    Most mount off of two studs screwed into bosses on the sides of the distributor angle drive castings. As I said before one of the coil brackets has the ballast resistor on the side for clearance on the other coil.

    Brian Brown
    Patrick Ottis Co.
     
  13. DWR46

    DWR46 Formula 3
    Honorary

    Jun 19, 2012
    2,038
    Brian: Very good observation. The car in the photos is 6529. I would have posted a photo of the GTS, but I would have to remove the air cleaner as it is the Snorkel style and you cannot see behind it.
     
  14. Motob

    Motob Formula 3
    Professional Ferrari Technician

    Nov 11, 2003
    2,365
    Frederick, Maryland
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    Brian Brown
    #14 Motob, Oct 25, 2014
    Last edited by a moderator: Sep 7, 2017
    Here are three Marelli BZR201A ignition coils with brackets. You can see that the coil in the center has the ballast resistor moved to the side of the coil.
    We had a car come in with non-original coils without ballast resistors and had to duplicate the bracket that Ferrari originally used. The coil on the right is the one with the bracket that we modified.
    Image Unavailable, Please Login
     
  15. Motob

    Motob Formula 3
    Professional Ferrari Technician

    Nov 11, 2003
    2,365
    Frederick, Maryland
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    Brian Brown
    #15 Motob, Oct 25, 2014
    Last edited by a moderator: Sep 7, 2017
  16. Motob

    Motob Formula 3
    Professional Ferrari Technician

    Nov 11, 2003
    2,365
    Frederick, Maryland
    Full Name:
    Brian Brown
    #16 Motob, Oct 25, 2014
    Last edited by a moderator: Sep 7, 2017
    Here is how the coils mount to the distributor angle drives. It is a tight fit, as are most things Ferrari. One coil sits higher in its mounting bracket than the other.

    The correct BZR201A coils for your 275GTS should have brown tops on them. They are getting very hard to find and are now very expensive. If you show the car, a keen judge may deduct points for a black top coil.
    Image Unavailable, Please Login
     
  17. ISBC90T

    ISBC90T Rookie

    May 16, 2007
    30
    Smalltown USA.
    Thank you to everyone!!

    Brian I have sent you an email.
     

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