Help ... i've "lost" my 308 ignition timing marks ! | FerrariChat

Help ... i've "lost" my 308 ignition timing marks !

Discussion in 'Technical Q&A' started by F308 MAN, May 30, 2008.

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  1. F308 MAN

    F308 MAN F1 Rookie

    Jan 19, 2004
    2,907
    Isle of Man
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    Dave S
    #1 F308 MAN, May 30, 2008
    Last edited: May 30, 2008
    i've just rebuilt the cams etc on my single distributor, 1980, 308.
    i) the valve timing is spot on.
    ii) the flywheel sits at TDC1-4.
    iii) my white mark sits at 6 deg BTDC on the flywheel.
    iv) timing light connected to #1 plug lead.
    v) the rotor arm is set to #1 cylinder lead.
    v) she fires up and runs (not too well) but i cannot see the timing mark on the flywheel.

    does anyone have any clues ?
    what sort of linear measure on the flywheel, does the rotary min/max adjustment on the distributor cover ?

    i've adjusted the distributor/cam spline connection, one spline either way without success.

    can anyone help ?

    many thanks in anticipation and kind regards,
    david
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
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    #2 Steve Magnusson, May 30, 2008
    Last edited: May 30, 2008
    Is this a euro version with some sort of electronic ignition (that isn't adjustable for the rotor-to-firing event relationship)? Count the number splines and divide into 360 deg -- it's something like 20~24 so each spline is 15~18 deg (IIRC) and the arc length, marked at a ~6" radius, would be on the order of ~2 inches -- but doing this (to move the firing event relative to the crankshaft) will mess up the rotor-to-cap phasing. If you haven't messed with relationship between the rotor and the firing event (or it's a built-in fixed arrangement), 'tis strange that you're having trouble.

    Are you sure that step ii) is "the flywheel sits at TDC1-4 AND cylinder #1 is at the end of its compression stroke"?
     
  3. F308 MAN

    F308 MAN F1 Rookie

    Jan 19, 2004
    2,907
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    Dave S
    hello steve, and thank you.
    yes, it is the euro version as stated.


    yes ... the front bank cams were held in position as i changed that cambelt .... all four cam/cam cap marks line up correctly.
    'twas the rear bank i had to dismantle to replace the shim bucket on #4

    is there a device i can use (similar to a light bulb) that will tell me exactly when the plug #1 fires in static mode (no finger jokes, please) ?

    thanks again,
    david
     
  4. Ken

    Ken F1 World Champ

    Oct 19, 2001
    16,078
    Arlington Heights IL
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    Kenneth
    Funny. I just did the same thing on my Lotus: redid the timing and couldn't get the mark in the strobe. It also ran like crap but ran. I had the #1 and #2 plug wires reversed. Yes, a 4 banger still started and ran like that but how, I have NO idea. Put the sensor on the other plug wires and see which one makes the marks appear. Keep in mind the cylinder 180 degrees out of phase will also give a reading on the flywheel.

    Ken
     
  5. F308 MAN

    F308 MAN F1 Rookie

    Jan 19, 2004
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    Dave S
    thanks ken, i'll have a go.
    i just had a moment where i thought maybe i have the front bank firing on the comp stroke, and the rear bank firing on the ind. stroke ... but that would be impossible given that the front bank hasn't been touched (bar for belt change), and all four cam to cam cap marks align.

    i am going to start again from scratch and see what happens.

    perhaps i can stick an old plug in #1 lead, earth (ground) it and it should spark (as i wind the crank around manually) as cyl. #1 hits 6 deg BTDC ... ???

    trouble is, i'm under pressure to fix this and other projects on the car ... this doesn't help !

    many thanks once again.
    cheers,
    david
     
  6. BigTex

    BigTex Seven Time F1 World Champ
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    Dec 6, 2002
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    Bubba
    Careful running the electronic ignitions ungrounded, (plug loose, as you are thinking) better to have the plugs installed and use timing light or colortune or something.....
     
  7. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
    26,975
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #7 Steve Magnusson, May 30, 2008
    Last edited: May 30, 2008
    I don't think it would hurt to try:

    1. With the timing light first on the coil wire,

    2. turn the key "on", and

    3. rotate the dist housing back and forth and see if you can detect something firing -- there should be enough "teeth" on the magnetic rotor that at least one would pass by the (firing) stator.

    If it does fire, then try moving the timing light to the #1 cyl wire, etc. -- HTH.
     
  8. Ken

    Ken F1 World Champ

    Oct 19, 2001
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    Kenneth
    Not that I'm aware of. I use an incandescent bulb; the thing is the point the bulb goes on as you twist the distributor forward is not the place it goes out when you twist it back. So it's a bit of an art, but you want the distributor body at the point just before the light goes on. My car, clockwise advances the timing, and I twist clockwise until just before it goes on. That seems to set it spot on (or close enough for fine tuning once the car is running). You can be off a few degrees and the car will still start; it's not rocket science like cam timing is.

    Ken
     
  9. F308 MAN

    F308 MAN F1 Rookie

    Jan 19, 2004
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    Dave S
    FOUND IT !!!

    SORTED !!!

    ONE HAPPY BUNNY NOW !!!

    THANKS EVERYONE !!!!

    off to watch some racing now .... www.iomtt.com

    cheers,
    david
     
  10. BigTex

    BigTex Seven Time F1 World Champ
    Owner Rossa Subscribed

    Dec 6, 2002
    79,418
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    Bubba
    Awesome you got it sorted, mate, enjoy the races and later tell us all where it went wrong....LOL!
     

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