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Automotive Con rod length increase

  1. Jan 29, 2013 #1
    hello, what happen if cod rod length increase by few hundred microns?
  2. jcsd
  3. Jan 29, 2013 #2

    Ranger Mike

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    the closest pistojn to cylinder head clearance should be 0.050" ( 1250 microns) and having closer distance would mean the piston hits the cylinder head and bends the connecting rod. This is a V8 cast iron engine forged con rod spec and a general guide line so beware...
    Last edited: Jan 29, 2013
  4. Jan 29, 2013 #3
    my supplier asking for 150 micron increase in length tolerance?
  5. Jan 29, 2013 #4
    Well is an online forum really the place to be asking for advice? We don't know your design, we don't know what is important.

    What happens if the conrod tolerance is increased by 0.15mm? The conrod could potentially be upto 0.15mm longer than previously spedified. That's really the only sensible answer we can give.
  6. Jan 29, 2013 #5
    Thanks Chris for your concern, It all about engine performance that concern me.
    My liitle concern about what it will increase the piston thrust.
  7. Jan 29, 2013 #6


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    The thrust will increase by exactly -100%, if the piston hits the cylinder head.

    As the others said, it needs MUCH more information to answer to your question.
  8. Feb 1, 2013 #7
    What is the rod length?

    What is the piston top to cylinder head clearance?
  9. Feb 4, 2013 #8
    rod lenght-150mm
  10. Feb 5, 2013 #9
    Unless you are running a true hemispherical combustion chamber, you need to think about detonation in the quench areas. But, more importantly, you need to be asking why your supplier can't hold tolerance any longer.
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