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308 Ignition & Cam Timing HELP !!!

Discussion in 'Technical Q&A' started by gary308gtb, Jan 26, 2004.

  1. gary308gtb

    gary308gtb Rookie

    Oct 9, 2003
    41
    Can someone please explain to me how to determine whether my '78
    308GTB U.S. Version's CAM TIMINGS can be checked to see if they are timed properly ? How do you know if you ae timed correctly for the CAMS ?

    Secondly, how can I know whether or not my IGNITION TIMING is also correctly timed or set ??? What degree angle setting should I achieve ?

    What about distributor settings ? Aside from checking the workshop manual, how do I know whether the settings are correct ?

    My car runs perfectly at low rpms. At 4000 to 4500 and up, it feels like the engine has hit a wall and cannot achieve higher revs.
     
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  3. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,496
    Texas
    Full Name:
    Steve Magnusson
    The first level for checking the cam timing would just be examining the factory marks on the cams and cam caps at the #1 TDC firing position (requires camcover removal). Beyond that you'd need to measure the cam lobe displacement (or more accurately every lobe displacement) vs crankshaft angle and then best fit/average to the desired position.

    However, I wouldn't do anything in the cam timing area until I was very certain (as your posts suggests) that the ignition stuff is working well (and if the ignition was OK, I'd make sure the fuel system was OK too before resorting to the more extensive cam work).

    The proper idle timing setting differs depending on whether you have the stock R1/R2 stuff working or are just running the R1 points (or some other "single-trigger" mechanism) -- what is your ignition configuration?

    The flywheel also has extra marks at 34 deg BTDC for checking each distributor advance at 5000 RPM (and it doesn't matter whether you have an R1/R2 or R1 only set-up for this) -- this is where I'd start. Since you report that it won't get to 5000 RPM you might make some additional rough in-between marks on the flywheel edge or clutch housing beforehand using some paint or fingernail polish (29 deg BTDC at 4000 RPM and 24 deg BTDC at 3000 RPM would be the targets).
     
  4. Matt Morgan, "Kermit"

    Matt Morgan, "Kermit" Formula Junior

    Nov 12, 2003
    405
    Ferndale, WA
    It sound like it is probably one or both are off. The stock timing notches are IMO way too small to accurately dial one in. And often they are off a tad.
    By useing a dial indicator, and a good degree wheel you know that it is set right on.
    HTH,
    Kermit
     
  5. pma1010

    pma1010 F1 Rookie

    Jul 21, 2002
    2,559
    Chicago
    Full Name:
    Philip
    Distrib advance?

    Steve post the on engine checking procedure. To check the complete curve, you've got to pull the distribs and test on a purpose built machine.
     
  6. Mark 328

    Mark 328 Formula Junior

    Nov 6, 2003
    510
    Orange, Ca
    Full Name:
    Mark Foley
    Gary:
    A quick view of one cam's timing can be made by looking into the oil fill hole. Additionally, on the 328 there are some reference marks visable from looking toward the camshaft from the shield behind the cam covers (pointers are on the shield). These makes are hard to line-up and in many cases the shields are removed.
    When looking at the flywheel marks, they too are very hard to see--make sure you are looking at the right mark. It is easiest to line the marks-up thru the oil filler hole first then look for the mark on the flywheel.
    Good Luck,
    Mark
     
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  8. Mark 328

    Mark 328 Formula Junior

    Nov 6, 2003
    510
    Orange, Ca
    Full Name:
    Mark Foley
    Also, as far as the ignition timing, I am not sure why the timing could not be checked with an advance timing light and a tachomter? I have not done this yet, but it seems like it would work?
    Mark
     
  9. Mike Florio

    Mike Florio Formula Junior

    Jun 19, 2003
    573
    NW Rural Nevada
    Full Name:
    Mike Florio
    Mark:
    You are correct. One could run the engine at a specified RPM, dial in the advance on the timing light, then check for TDC. Presumably you could map your advance curve by running through the rev range, and dialing in the advance on the timing light until you brought the timing mark to TDC at, say, 500 RPM increments.

    Pretty expensive Distributor Tester machine!

    Said by someone who finally broke down, bought an old Allen Distributor tester on eBay and spent three months rebuilding and calibrating it. Its amazing how easy it is to set up a distributor on one of these machines. I have even figured out the advance mechanism works, and have adjusted the springs and weights to get an in-spec advance on both distributors, which now also match one another.
     
  10. gary308gtb

    gary308gtb Rookie

    Oct 9, 2003
    41
    THANKS STEVE, MATT, PMA1010, AND MARK,

    Thanks for the technical advice, will discuss all of these with the Ferrari Mechanics as soon as possible.
     
  11. Sean F.

    Sean F. F1 Rookie

    Feb 4, 2003
    3,003
    Kansas
    Full Name:
    Sean F
    OK Mike, how much do you want to set my distributors for me ;)
     
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  13. Mike Florio

    Mike Florio Formula Junior

    Jun 19, 2003
    573
    NW Rural Nevada
    Full Name:
    Mike Florio
    Sean:

    Sorry, I'm not in that bidness. You (or anyone else on this board) are welcome to come and use the machine. I'm in NE Nevada, about 100 miles SE of Reno. Stop at Krispy Kreme in Reno and bring a dozen of those puppies with you. I'll supply the coffee.
     

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