'77 308 Ignition Timing Question | FerrariChat

'77 308 Ignition Timing Question

Discussion in '308/328' started by yank05, Aug 5, 2009.

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  1. yank05

    yank05 Formula Junior

    Nov 8, 2003
    272
    New England
    Full Name:
    Anthony
    Hi,

    My car ('77 308, U.S. car, all stock, breaker-point ignition) has been running great for years timed at 7 deg BTDC @ 1000rpm (running R1 points only).

    I recently took it for a belt service to a Ferrari mechanic with 40 years exp. here in New England. He was the one who originally set the car up 6 years ago and timed it to 7 deg BTDC.

    I'm very sensitive, and noticed that when I got the car back, it sounded slightly different at idle (a little quieter, muted), but started up a little rougher (ever so slightly). The car also had a little more power in upper rpm ranges - revs a little more free.

    The mechanic did not touch the carburetion, but did set the timing to 10 deg BTDC when he re-installed the distributors, explaining that this was what the Euro cars were spec'd to (I still need to check documentation to convince myself).

    Anyway, is anyone running this kind of advance? Is this too advanced with the potential to cause harm? I'm thinking of re-timing the car back to where it was....

    Thanks (in advance.... ; )

    Anthony
     
  2. yank05

    yank05 Formula Junior

    Nov 8, 2003
    272
    New England
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    Anthony
    ...by the way....just want to add that the distributors did not need to be set up (they were about 6k miles ago) - they were just removed from the car for the belt service (as the cam covers were removed)...thanks
     
  3. AZDoug

    AZDoug Formula 3

    Jun 17, 2009
    1,606
    Along the Verde , AZ
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    Doug
    #3 AZDoug, Aug 5, 2009
    Last edited: Aug 5, 2009
    What is the timing advance at 5000 RPM?


    Static advance and full advance are connected together by the centrifugal advance curve, and that could have been set up in any number of ways.

    Simply advancing the base timing 3 degrees shifted the entire timing curve up by 3 degrees.

    Doug
     
  4. yank05

    yank05 Formula Junior

    Nov 8, 2003
    272
    New England
    Full Name:
    Anthony
    that's what i think was done - the base timing was advanced only, shifting the entire curve
     
  5. fastradio

    fastradio F1 Rookie
    BANNED Professional Ferrari Technician

    Apr 26, 2006
    3,664
    New England
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    David Feinberg
    #5 fastradio, Aug 6, 2009
    Last edited: Aug 6, 2009
    As to be expected with slightly more initial and total advance...

    Unlikely, as with the increase in base timing, the carbs would have to be adjust to obtain the correct idle speed. (Idle speed rises as the static (base timing) is increased.


    10 degrees initial advance is hardly "alot"...but, as already posted, what's the total maximum advance. Ferrari is quite specific in their timing procedures to set the maximum advance first, then verify that the base setting, typically at idle is correct. In that 99% of the distributors in these cars are clapped out and in dire need of rebuilds, the maximum advance setting is really all I'd be concerned with. If the two timing specs can't be acheived, or their just too far off, then a distributor rebuild is in order...

    Potential to cause harm: Great question, but highly unlikely. A spark plug visual inspection will reveal detonation.

    For what it's worth, a guy with 40 years experience working on your Ferrari is a great thing! (I'm just shy of 30 years of experience with these cars.) He knows that what "worked then" may not work as well, now...Remember that Ferrari speced the NGK equivalent of BP8ES plugs for these cars. Anyone who's worth their salt know that, that plug under USA driving conditions is just way too cold. Experience matters here...run your thought by your tech.

    Best,
    David
     
  6. yank05

    yank05 Formula Junior

    Nov 8, 2003
    272
    New England
    Full Name:
    Anthony
    Thanks! Distribs rebuilt 6 years/6k miles ago - worked perfectly - no trouble in all these years - will check at high rpm as well - just initially concerned with this timing shift by 3 deg. Spoke to mechanic today, he calmed my worries and agreed to bring it back to 7 deg if I would like him to - overall, I liked the way the car sounded and felt before the change, even given the slight increase in response in the upper registers....running BP6ES - same plugs for years - plug color always textbook "tan" for a well-tuned engine.....

    Thanks Again!

    Anthony
     
  7. Ferraripilot

    Ferraripilot F1 World Champ
    Owner Project Master

    May 10, 2006
    17,171
    Atlanta
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    John!
    Euro market distributors are supposed to run at 13 degrees advance at idle. The owners manual shows this to be the correct idle setting as well. The Euro 127G distributor does not advance as much as the 159 (US cars etc) because they specifically wanted the Euro cars to have a snappier off idle throttle response, which is what a 13 degree initial advance offers. Total timing on all carb 308s no matter the market is 39-41 degrees. 34 degrees advance at 5000rpm is listed as a tuning point prior to the last and most stiff advance spring kicking in. Total advance for these Marelli distributors is reached at 6k rpm. Just make for darn sure you are getting correct total advance. Personally, I marked my flywheel showing all the degrees after 34 degrees all the way to 41 degrees so I could verify I was getting correct total advance because Ferrari did not mark anything past 34! I also modified my distributor so I can run a 12-13 degree initial advance idle as these engines repond much better off idle with this arrangement. Also note that Nick's electromotive system runs a 10 degree idle, but immediately switches to 33 by 2000 or 2500 rpm!
     
  8. yank05

    yank05 Formula Junior

    Nov 8, 2003
    272
    New England
    Full Name:
    Anthony
    This is great info - thank you! I have a US car - I'm a little confisued at the statement "The Euro 127G distributor does not advance as much as the 159 (US cars etc) because they specifically wanted the Euro cars to have a snappier off idle throttle response, which is what a 13 degree initial advance offers."

    Did you mean that the 127 DOES advance more than the 159, hence the 13 deg setting? Thanks!

    I will check the total advance - if okay, I am now tempted to keep the 10 deg advance at idle - the car is more repsonsive - i think i'm just used to the standard 7 deg idle setting which gives me smoother start-ups and sounds "open" at idle...but where it counts, it does make a difference - better of idle response, etc....Hmmmm......
     
  9. Ferraripilot

    Ferraripilot F1 World Champ
    Owner Project Master

    May 10, 2006
    17,171
    Atlanta
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    John!

    The 127G springs and arms do not allow the center 4 sided hub to advance as much as the 159 distributors. As in: the 159 distributor can advance from 7 degrees to 41 degrees while the 127G advances from 13 degrees to 41 degrees. The 127G brass arms inside the advance mechanism are a bit thicker than that of the 159 so they essentially have a different starting point, which when set up correctly is about 13 degrees (+ or - 2).

    The Ferrari manual always notes degrees for these units in + or - 2 degrees in their advance charts. 41 is the very top of the curve and I personally do not push it past about 40.

    Just out of curiosity, who is doing the work for you? I went to college in Boston and fiddled around in the area with exotics quite a bit and know many of the people in the circle out there.
     
  10. Yoric

    Yoric Formula Junior
    Rossa Subscribed

    Jan 8, 2005
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    Yoric
    Can someone provide those of us who have not done it before, a detailed step-by-step procedure on how to set the timing on these early 1976-79 308's? With two distributors present and timing marks partially hidden, it's a bit daunting for me, but I would like to learn to do it. Like most others, I suspect, my car no longer has the microswitch which originally retarded the ignition at idle. I am reasonably sure that I'm operating on just two sets of points rather than four.
    Here's hoping one of the good wrenches will volunteer.
     
  11. Yoric

    Yoric Formula Junior
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    Yoric
    No one? Anyone?
     
  12. yelcab

    yelcab F1 World Champ
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    Nov 29, 2001
    12,661
    San Carlos, CA
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    Mitchell Le
    You use a white marker, or bright paint, and mark the spot on the flywheel where you want the timing to be.
    you loosen the distributor bolts so you can rotate it.
    You hook up a timing light trigger clamp to the number 1 spark plug wire
    Fire up the engine, squeeze the trigger on the timing light, point it at the flywheel mark.
    You will see the light flashes. Then you rotate the distirbutor until the mark you have made lines up with the index.
    You retighten the disty bolts.

    You now repeat with the front bank dizzy, with the timing trigger clamp over the number 5 wire.
     
  13. yank05

    yank05 Formula Junior

    Nov 8, 2003
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    Anthony
    Yes, a tutorial on this topic would be a great complement to all the others on carbs, etc...!
     
  14. Neonzapper

    Neonzapper F1 Rookie

    Oct 19, 2008
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    Mykol
    +1 (an informative post)
     
  15. Beta Scorpion

    Beta Scorpion Formula 3

    Jun 22, 2006
    1,336
    #15 Beta Scorpion, Aug 8, 2009
    Last edited: Aug 8, 2009
  16. Yoric

    Yoric Formula Junior
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    Yoric
    Thank you BetaScorpion. Very informative and I like all of the detail you've gone into. One question--what is the Crane XR 3000 box that sits under the coils with the little red light? Is this an ignition modification? Could you provide some details?
     
  17. Beta Scorpion

    Beta Scorpion Formula 3

    Jun 22, 2006
    1,336
    Yes the Crane unit is the replacement for the points. I prefer originality and never had problems with points in the past, but the prior owner put the Crane units on, so I re-mounted them for somewhat of a 'stealth' appearance. The little red light makes static timing easy.
     
  18. robertgarven

    robertgarven F1 Veteran
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    Feb 24, 2002
    5,269
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    Robert Garven
    Friends,

    Just to be correct, the #1 wire is the rear bank closest to flywheel? and #5 wire is the front bank closest to distributors?

    Rob
     
  19. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
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    Steve Magnusson
    Rob -- Quit using the words "front" and "rear" as this depends on where you are standing ;)

    This OM figure describes all -- the long snout on the crankshaft is the timing belt end (i.e., cylinders #4 and #5 are close to the distributors):
    Image Unavailable, Please Login
     
  20. robertgarven

    robertgarven F1 Veteran
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    Feb 24, 2002
    5,269
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    Robert Garven
    Thanks Steve, to me always the front bank is the one near the firewall and the rear bank is at the rear of the car. I appreciate all your help. The car is running fantastic it just stumbles a little bit off idle. I took the airbox off tonight so I’ll be checking the carburetors and the timing. It has two distributors both the early S159 a units with one set of points.

    This is the frame off car that I paid a fortune for, rebuilt engine, rebuilt carbs, rebuild distributors I’m hoping it’s just an adjustment. For what it’s worth one of the car Al built just sold for 140 K at Scottsdale and another is listed at Hemmings for 180 K. I’ll never sell mine but I just want to get running good.

    Rob
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  21. derekw

    derekw Formula 3
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    Sep 7, 2010
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    Robert, #1 is rear bank right, #4 rear bank left, #5 front bank left, #8 front bank right. A cunning ploy to discourage non-Ferrari servicing.
     
    robertgarven likes this.
  22. robertgarven

    robertgarven F1 Veteran
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    Feb 24, 2002
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    Thank you all I resurrected several timing threads to glean advice!
     

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