Torque for Superformance cam drive nuts? | FerrariChat

Torque for Superformance cam drive nuts?

Discussion in 'Technical Q&A' started by greggbferrari, Apr 13, 2012.

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  1. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #1 greggbferrari, Apr 13, 2012
    Finally getting my 308gt4 back together. I'm using the hex drive nuts (available from Superformance in the UK) instead of new ring drive nuts.

    If I'm reading it right, the WSM says 13 kg-m, which I believe is 94 ft-lbs. That seems a lot for the 5-6 fine continuous threads on those nuts before the nut is notched. I suppose the ntoches are to lock the nuts, but they don't appear to grip the threads.

    Anyone used the Superformance hex cam drive nuts and torqued them to 94 ft lbs?

    Thanks.
     
  2. PFSEX

    PFSEX Formula Junior

    Jun 30, 2006
    843
    Las Vegas
    Full Name:
    John Ratto
    #2 PFSEX, Apr 14, 2012
    What is the size of the nut? bolt?

    torque is udually proportional to size of the fastener.

    90 ft-lbs would indicate a BIG fastenener - something on the line of a wheel nut-bolt.

    90 ftlbs will snap a small fastener or pull the threads
     
  3. fastradio

    fastradio F1 Rookie
    BANNED Professional Ferrari Technician

    Apr 26, 2006
    3,664
    New England
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    David Feinberg
    #3 fastradio, Apr 14, 2012
    A couple of things...
    Torque to proportional to numerous factors. Two of which are thread pitch and diameter.
    The thread pitch is 17x1.0mm, which will support a fairly high torque figure
    The actual torque figure is 12 kg-m (87 lb-ft.)
    The factory "jet" lock type nut is far superior to anything else for that critical application.
    Once the bearing is seated and the nut tightened, the notches will 100% engage the threads. If not, there are much bigger problems to contend with.
    Other than not having, or wanting to spend the money for the correct tool, why take a risk and use an unknown commodity in such a critical application. The factory nuts are dirt cheap and even an aftermarket tool is less than $100.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,115
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #4 Steve Magnusson, Apr 14, 2012
    13 and 12 kg-m are both correct (depending on which WSM you believe ;))

    It's a fine thread pitch, but the diameter is huge, as David mentioned, so no worries IMO -- AFAIK, no one has ever reported stripping those threads on FChat...
     
  5. greggbferrari

    greggbferrari Karting

    Jan 4, 2010
    121
    Seattle, WA
    Full Name:
    Gregg Brown
    #5 greggbferrari, Apr 14, 2012
    Gentlemen, thank you. Careful cleaning, a little blue loctite, 13 kg-m (94 ft-lbs) and no apparent problems.

    It's kind of thrilling to see cams in the heads after six months. :)
     
  6. fastradio

    fastradio F1 Rookie
    BANNED Professional Ferrari Technician

    Apr 26, 2006
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    David Feinberg
    #6 fastradio, Apr 14, 2012
    I do have a 17x1.0mm die if the need should ever arise...

    You're welcome and congrats on your progress!
     

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