Ridemalibu Motorcycle Rentals & Tours – Los Angeles CA
  1. Holiday Greetings. For those asking about Black Friday/Cyber Monday specials... Since we're such a tiny operation, it's tough to offer much... But we're again offering free shipping on $99+ orders to our U.S. customers on any in stock GTM product! Now through Monday at midnight, PST. Use POST-COVID-FREE discount code at checkout on our online Store link above - We truly appreciate your support. PLEASE Support small businesses!

Metal temperature and torque values

Discussion in 'Chat & Tech Info' started by DeadEye, Sep 15, 2021.

  1. DeadEye

    DeadEye GT Reference GT di Razza Pura

    Joined:
    Jun 13, 2020
    Messages:
    1,089
    Likes Received:
    604
    Location:
    Eastern Ontario - Western Quebec
    One of those questions just popped into my head...
    You take the bike out to warm it up, before the oil change, you go a little further that planned and the oil comes out like water.
    When closing everything up, I start thinking , everything is hot and has expanded, what ever I tightened now, when they cool will they be loser, loosen ?, perhaps be under the recommended values ??

    This could/would apply to anything tightened when hot...
    This would be why your told to check the valve clearances cold !
     
    RodgerMillan likes this.
  2. Raven

    Raven High Miler GT Famiglia

    Joined:
    Jul 3, 2017
    Messages:
    749
    Likes Received:
    427
    Location:
    Lac Ste. Marie, Qc
    If the fastener and what it is bolted into are the same metal, there should be little difference in torque value. If they are dissimilar metals there could be a small difference.
     
  3. Michael Moore

    Michael Moore Tuned and Synch'ed GT Contributor

    Joined:
    Nov 21, 2016
    Messages:
    26
    Likes Received:
    19
    Location:
    San Francisco, CA
    Matweb has a coefficient of temperature expansion for A356 (a common good quality aluminum casting alloy) of
    11.9 µin/in-°F @Temperature 68.0 - 212 °F. For 4340 steel (high strength alloy) it shows 6.83 µin/in-°F @Temperature 68.0 °F. So if the things you are measuring include both ferrous and aluminum materials, you may see different clearances between the items at different temperatures. Using the numbers above can give you an idea of how much the expansion rates differ with changes in temperature.

    cheers,
    Michael
     
  4. DeadEye

    DeadEye GT Reference GT di Razza Pura

    Joined:
    Jun 13, 2020
    Messages:
    1,089
    Likes Received:
    604
    Location:
    Eastern Ontario - Western Quebec
    I am guessing that most motorcycle crank cases are made of aluminium, and the drain plug bolts are some type of steel, there being less expansion in the steel, there would be a diffference after it cooled from 90c to 20c But not as much as the Aluminium.
    I was initially concerned , being unsure about whether they would be getting tighter or looser.
    So maybe they would be a bit looser, but not measurably so.
    ( at least not by me with my craftsman torque wrench)

    Thanks for the input.
     

Share This Page