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Thread: Rocker Shaft Sealing Bolt

  1. #1

    Default Rocker Shaft Sealing Bolt

    Hi,
    I want to ask about Sealing Bolts 20mm for rocker arms.

    in Manuals (1997) Page 6-32 gives 49Nm

    -unscrewing I measured the value 107,6Nm
    Click image for larger version. 

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    -the aluminum washer was tightly compressed

    Click image for larger version. 

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    question - do a new washer tighten with 49Nm ?

  2. #2
    Join Date
    Sep 2005
    Location
    Garden of England
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    2,436

    Default

    i'd suspect yes, as that's what the manual states, it's more to do with stripping the threads, as all the torques are less than what would be normal into steel.

    the high torque to loosen the bolt is probably the result of years being in there with micro corrosion and 'sticktion' holding it in! removing the 4 steering input shaft bolts on the steering rack resulted in 3 broken/ruined tools and ended up with the heads being drilled out. with a large shifter attached to 'break the seal' they then unscrewed with my fingers.... three tools ruined and they are just M6 screws!..

    sometimes they are just tight through habit!
    aka Jonathan!!

    '92 charlotte green auto.... as a daily
    '37 Ford Y street rod......... something for the weekend!

  3. #3
    Join Date
    Oct 2006
    Location
    Essex, Colchester
    Posts
    2,259

    Default

    Copper grease all contact surface when re-installing would help next time....albeit may be 25 years time.

    SS
    Range Rover Evoque luxury family mover...my first diesel car!!
    Porsche 996 911Turbo.......New Daily run around with 4 seats ...2 for kids...
    Black/black 95 NSX NA with mk1 Ary exhaust....Now sold
    Red/Black 91 NSX treasure.....FI No more NA
    Silver/Pearl White/Black 1993 NSX 3.0 5 MT NSX ZAZ R-GT Twin Scroll Turbo

  4. #4
    Join Date
    Dec 2007
    Location
    Switzerland
    Posts
    834

    Default

    Please, no copper grease on the NSX. Use ceramic paste instead.

  5. #5

    Default

    I think that because of my weak English (I use a translator) I was misunderstood.
    This engine was not disassembled in the past.
    My attention turned to deep groove of the washer.
    I unscrewed the second screw and decided to check the moment-force.

    Because by tightening the first one with a moment of 49Nm, the washer did not deform at all
    I am not talking about a seized screw ... etc ...
    during assembly on Factory the torque used was higher than described in Manuals.
    Because there are a few inaccuracies in manuals for example: 16Nm for Pan baffle screw, according to Kaza experience, there are too many

    That's why I ask experienced Colleagues

    Mario from Poland

    P.S.Goldi,as you said earlier, I use ceramic paste

  6. #6
    Join Date
    Dec 2007
    Location
    Switzerland
    Posts
    834

    Default

    In the 91 SM the torque is noted even more: 60 Nm. I'm surprised it's 49 Nm in SM of 97. Draw your own conclusion...I'd use 49 Nm now because of the later SM corrections.
    A washer has been designed to compress by factor... The one in the picture above seems to be a little bit too flat. While you bolt on the screw you get an idea of how much the washer gives in, depending on the thread and rotation in degrees you have quite a good indicator.

    I don't think the high torque needed to unscrew it was due to corrosion because the threads of that screw are in constant contact with engine oil.
    Last edited by goldnsx; 11-03-2019 at 09:51 AM.

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