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348 Tricks for placing the belt ?

Discussion in '348/355' started by 348steve, Jun 26, 2019.

  1. ernie

    ernie Two Time F1 World Champ
    Owner Lifetime Rossa

    Nov 19, 2001
    21,849
    The Brickyard
    Full Name:
    The Bad Guy
  2. 348steve

    348steve Karting

    Jul 18, 2018
    137
    Full Name:
    Stephen G
    Ernie and FBB ... you guys are entertaining! Like to get things done!

    I'm getting pretty good at this whole darned process, as it calls for the belt to go on and off a few times in order to get good alignment with the camshaft dowel holes! The thing I have learned during the past few hours more than anything else is that the process is iterative! You can line the whole thing up perfectly on any given attempt, but after you rotate the engine, there will be change! Also, when you finally reach the last part of the process when you are carefully moving the dowels while the cogs remain in place, you are not guaranteed to find a hole, so the game starts to feel a little like Snakes and Ladders, it is now time to go back a few rungs.

    FBB ..... One thing I am yet to digest perfectly is the 1st page you had on the Degreeing Cams post from May 2007, where you calculated the centerlines of the cams using the "magical schematic" from the WSM. But I'll get it!
     
  3. 348steve

    348steve Karting

    Jul 18, 2018
    137
    Full Name:
    Stephen G

    OK, finally got it, and of course the math was correct. (Lead+180+Lag)/2 - Lead = the Intake center line. The reason why I could not understand your original post was because the font was not recognized by my browser on this "older technology forum" and the "minus" sign showed up as a square .... :)






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  4. 348steve

    348steve Karting

    Jul 18, 2018
    137
    Full Name:
    Stephen G
    ernie, copterjon and steved033 like this.
  5. 348steve

    348steve Karting

    Jul 18, 2018
    137
    Full Name:
    Stephen G
    OK, here is what should be the final post on this thread:

    -
    The shims are all in and all lash is perfectly in spec. That took a long time and three separate orders of shims. Pain in the butt.

    - The belt/cams went on in an iterative process; you line it all up, install the belt on locked cams and free cogs, set the pins, release the cams, rotate the engine and tension the belt. The previously perfectly lined up marks will move! Then you individually adjust each cam till you have the factory marks lined up. Holding cams, moving pins, etc....

    - Then you get your trusty dial gauge and spend a bit of fiddly time getting it setup so that you can actually measure to see if your cams are in spec, or in other words if the factory marks are worth their salt.

    - The marks were 110% perfect, using the lobe centerline method. Right down to the 1/2 degree.

    Thanks for the help!

     
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  6. fatbillybob

    fatbillybob F1 World Champ
    Owner Consultant

    Aug 10, 2002
    16,807
    socal
    Nope! I got last post...Good Job! The weather is great go driving.
     
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  7. Rupp3r

    Rupp3r Karting

    Aug 26, 2016
    127
    France
    Thanks for your experience 348steve will surely help me in this process also and good job!
     
  8. ernie

    ernie Two Time F1 World Champ
    Owner Lifetime Rossa

    Nov 19, 2001
    21,849
    The Brickyard
    Full Name:
    The Bad Guy
    Excellent!
    Thanks for the update!
    And that is another F119 with cam marks that are spot on. ;) For whatever reason the factory made the F119 cams dead nuts on the marks. Thank you to whoever was in charge of 348 cams at the Ferrari factory.
     
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  9. emac

    emac Formula Junior
    Silver Subscribed

    Sep 14, 2014
    600
    upstate SC
    Full Name:
    ernest
    Good read, thank you for posting the follow up stuff. I am planning a major(355) this winter, and this really helps take some of the mystery out of cam timing.
     

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