365 BB Cam Distributor Drive Question | FerrariChat
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365 BB Cam Distributor Drive Question

Discussion in 'Boxers/TR/M' started by ital351, Oct 22, 2008.

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  1. ital351

    ital351 Rookie

    Oct 18, 2006
    24
    Northern California
    Full Name:
    David
    #1 ital351, Oct 22, 2008
    After removing the 3 nuts and the distributor body, there is a rigid drive disk that engages the cam to drive the distributor. After removing the rigid disk, there is a large bolt with a lock tab that holds the distributor driver to the cam. Question -- does this distributor driver have splines that engage to the cam so the distributor can be indexed such as in other engines???

    Thanks guys,
    Ital351
    S/N 17929
     
  2. fastradio

    fastradio F1 Rookie
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    Apr 26, 2006
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    David Feinberg
    #2 fastradio, Oct 23, 2008
    Last edited by a moderator: Sep 7, 2017
    Actually, no. Unlike the 512bb and the BBi, the 365bb does not use a spline drive on the end of the cam to drive the distributor. If you were to remove that bolt, (which you have to if you were to change the drive oil seal), you would find the the currently visible distributor drive has a "male offset notch" which engages a corresponding "female offset notch" in the intake cam. Hence, there is no "additional" timing adjustability in the cam drive.

    So, the question that might come up is: What if I can't get the timing adjusted correctly just by turning the distributor, as its range of movement seems to be limited by the sloted notches in the distributor body. If you look carefully at the base of the distributor, you'll see that the "dual peg drive" piece is secured by two 8mm nuts. If you were to loosen those nuts, further timing adjustments are possible to the distributor, as the angle of the "peg drive" can be adjusted, relative to the static rotor position, by approximately 30 degrees.

    It is rare to do this specific adjustment, as if the engine is set at the AF13 timing mark and the rotor is aligned with the "Red" mark in the distributor, the position of the distributor should be in the middle of the adjustment range. If not, then the "peg drive" on the distributor base will need to be moved.

    Regards,
    David

    Notice adjustability at Part 5 and 7
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  3. ital351

    ital351 Rookie

    Oct 18, 2006
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    Northern California
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    David
    #3 ital351, Oct 23, 2008
    David, Thank you very very much for a great answer!!! I've been scratching my head, I know everything else seems right although I will check the cam timing anyway just for peace of mind. I imagine it is correct because the car does run strong. Plus, since I do my own work it will give me a more complete understanding of this magical machine. I will let you know what I find.

    Thanks again.
    Ital351
     
  4. fastradio

    fastradio F1 Rookie
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    David Feinberg
    #4 fastradio, Oct 23, 2008
    You are welcome. The WSM is not clear on the set-up procedure and there are a few ways to approach timing the beast. As the car is running well, I'd check the (ignition) timing at 5,000 RPM and see if the AF 36 mark is aligned with the pointer. This is your maximum advance point. Then, with the engine at idle (1,000 RPM), the pointer should be lined up with the AF 13 mark. The inherent problem with Boxers, and their distributors, is that the advance mechanism "seizes" and you're stuck at a fixed advance point. In this case, the car will run just "OK", but will be down on power.

    To verify that you're distributor is indeed advancing, just watch the PM or AF13 marks on the flywheel when you rev the engine up. If they appear stationary, your distributor is seized and this would help to explain why you might (think you need to) move the distributor's base position.

    Regards,
    David
     

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