308 GTB single distrubuter Timing set up | FerrariChat

308 GTB single distrubuter Timing set up

Discussion in '308/328' started by I FLV, May 10, 2018.

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  1. I FLV

    I FLV Rookie

    Apr 4, 2018
    13
    aberdeen
    Full Name:
    David Officer
    Hi all


    I recently have purchased a 308 GTB 1980 European car. The rear bank 5-8 has stopped firing. ( All had previously been working fine) On striping down the ignition system I found that all the components HT leads, twin rotary arm and induction leads were faulty due to the age. I have taken to leap to replace all ignition components coils leads impulse units and amplifiers. I have taken the engine to TDC and removed the distributor body. I forgot to mark the exact splines they came out from. What is the correct Advance degree setting / procedure for setting up the Distributor/ rotor.


    Regards


    Dave
     
  2. wrxmike

    wrxmike Moderator
    Moderator Owner

    Mar 20, 2004
    7,670
    Full Name:
    Mike
    Basic timing is that the lower level of the twin rotary arm rotor aligns to a mark ( slot) on the distributor housing when the engine is at TDC for PM 1-4 .
    The distributor is essentially 2 x 4 cylinder setups, each set of points are mounted on a base plate that can be moved to ensure the points are in phase to each other. If the baseplates are correcly setup they don't need to be moved, unfortunately many people make the mistake of unscrewing them to remove the points which means that you'll need to re-set the base timimg so that one set of pointd are on TDC for PM 1-4 and the other set is on TDC for 5-8 ( there are 2 sets of timing marks on the flywheel, one for each bank of cylinders.

    M
     
  3. I FLV

    I FLV Rookie

    Apr 4, 2018
    13
    aberdeen
    Full Name:
    David Officer
    Hi all trying to get the 308 started again its a single distributor, all leads, pick ups, cap and coils replaced I have taken the engine to TDC and aligned the rotar arm with the mark to the red spot on the distributor at number 1 cylinder but she still refuses to start a lot of back firing and pre iginition out the carbs. Is their something simple that I’m doing wrong. I read on here that I. Should take the the engine to 6 degree before TDC and set the mark on the rotar arm from their, but others say all is set up from TDC marking what is correct.?
     
  4. Andy 308GTB

    Andy 308GTB F1 Rookie
    Lifetime Rossa

    Jun 2, 2004
    2,660
    Essex, UK
    Full Name:
    Andy M
    I had a whole bunch of fun a few years back with the same ignition system that you have. I actually started a thread with this exact question: https://www.ferrarichat.com/forum/threads/distributor-marking-versus-tdc-or-6-degrees.431754/
    The thread doesn't really provide a direct answer... but it still may be helpful. Some of my other threads on the ignition system may be helpful.

    The big question is whether you have interfered with the bob weights and springs in the distributor? If you haven't touched them - that's good.
     
  5. I FLV

    I FLV Rookie

    Apr 4, 2018
    13
    aberdeen
    Full Name:
    David Officer
    Thanks Andy, I didn’t interfere with the bob weights or springs just the pick ups ,coils and distributor. Their was markings on the cam pullies on the 1-4 rear bank and they all lined up with TDC on number 1 cylinder, when I rotated the engine round to TDC on number 1 again on the second turn they don’t line up so hopefully I’m setting all up on the lnlet cycle stroke. The car was running before I changed everything but only on the 5-8 bank.I will try again tonight setting everything up using the 6 degree before TDC and Align the rotor to the red mark to see how this goes.
     
  6. Schulz308

    Schulz308 Formula 3
    Rossa Subscribed

    May 21, 2014
    1,503
    STL USA
    This forum thrives with help like this. You folks keep the hobby fun. Bravo
     
  7. wrxmike

    wrxmike Moderator
    Moderator Owner

    Mar 20, 2004
    7,670
    Full Name:
    Mike
    6 Degrees before TDC won't cause backfiring or refusal to start. There are 2 x 4 cylinder ignition systems in that distributor, (one for each bank ) , and each bank has its own set of points, rotor level and coil. The problem with the backfiring will be that you have mixed up the wiring between the banks, probably the points for one bank firing the other side or crossed over the coils. Attached is the extract from the owners manual that shows the correct wiring layout for the distributor and points
     

    Attached Files:

    thorn likes this.
  8. I FLV

    I FLV Rookie

    Apr 4, 2018
    13
    aberdeen
    Full Name:
    David Officer
    Thanks all, I Finally got the car started, The problem was someone in the past had marked the cam pulleys at TDC, the this was part of the marks i was going from along with Flywheel and Piston at number 1 cylinder the only major problem was this was in fact TDC on number 5 cylinder after swapping everything round the engine kicked into life and i set up the timing to 7% before TDC at 1100 rpm and it was reading 37% at 5500rpm all is well. Thanks again for your help.
     

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