Ignition timing issue for 246 euro Dino | FerrariChat
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Ignition timing issue for 246 euro Dino

Discussion in 'Technical Q&A' started by jula1234, Jun 29, 2022.

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  1. jula1234

    jula1234 Rookie

    Feb 27, 2022
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    James R LaFevers
    #1 jula1234, Jun 29, 2022
    my 1970 Dino ignition timing seems to be set up for cylinder 3 instead of cylinder 1. The book says it should time on cylinder 1 but timing light clearly shows that it does not , cylinder 3 lines up perfectly and the motor runs ok at idle. Is this unusual? Does it matter, as far as driving is concerned? The car hs not been driven for 35 years and I want to be sure it is set up correctly before I run it. It seems to me that if it is timed on cylinder 3 then timing should be correct for all the others, unless there may be a valve timing issue.
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
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    Steve Magnusson
    #2 Steve Magnusson, Jun 29, 2022
    No, for some reason they (I'm guessing the Fiat Engineers) used cylinder #3 instead of cylinder #1 for most everything. See your 246 OM -- the cam marks are aligned with the flywheel at PM3-4, and then the distributor is installed with a 240 deg offset of the dist rotor from the red mark on the dist housing that is used on other Ferrari models for cylinder #1.

    What "...book says it should time on cylinder 1" are you referring to?
     
  3. wmuno

    wmuno Formula Junior
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    Bill Muno
    #3 wmuno, Jun 29, 2022
    Did you check that the distributor wires go to the correct cylinders? Normally #1 on the distributor goes to cylinder #1. The rest of the wires then follow the firing order of the engine. For vintage V12's, cylinder #7 is the equivalent of cylinder #1 for the second distributor.
     
  4. jula1234

    jula1234 Rookie

    Feb 27, 2022
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    James R LaFevers
    #4 jula1234, Jun 30, 2022
    The book I was using is Angelo Wallace, “Ferrari 246gt-gts Repair and Workshop Manual” 1976, page 163. I may be misinterpreting what it says, however “a notch in the rotor and a corresponding one on the distributor case indicate the exact position for timing the distributor with cylinder 1” I can’t find anywhere else that mentions ignition timing
     
  5. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,825
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #5 Steve Magnusson, Jun 30, 2022
    That is technically correct statement -- when the dist rotor end is pointing at the red notch on the rim of the dist housing = that is the dist rotor position where the #1 cylinder would fire, but the pointer and mark on the harmonic damper are for cylinder #3 (not for cylinder #1). See page 52 in your 72/72 OM:
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    See page 69 in your 72/72 OM for how the distributor rotor end is intentionally not aligned with the red notch (but is offset by 240 deg) to be in the position where cyl #3 fires (to correspond with the pointer and mark at the front of the engine being for cyl #3):
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  6. jula1234

    jula1234 Rookie

    Feb 27, 2022
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    James R LaFevers
    #6 jula1234, Jun 30, 2022
    Ok, thanks, I just got a little spooked when the timing light lit up the wrong half of the pulley when hooked to #1 plug
     

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