Engine knock

Discussion in 'Small Block Mopar Engine' started by oley340, Aug 2, 2018.

  1. oley340

    oley340 Active Member

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    Looking for help or opinions... i have 340 stroked to a 416 as of late on start up it has developed a loud clanking sound that lasts around a minute or so. after that it is fine no power loss. Any help on this matter would be great Thanks
     
  2. Lelo Dart

    Lelo Dart *

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    Could be piston rock/slap. Classic on a stroker engine. The short forged pistons tend to rock in the cylinder and make that noise. After they warm up the clearance is taken up and the noise stops.
     
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    • moper

      moper FABO Gold Member FABO Gold Member

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      Clanking - like a metallic sound or more of a knock like you'd hear on a wood door? Pistons don't "ring". If it's more metallic ringing i'd look elsewhere.
       
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      • Max1196

        Max1196 Well-Known Member

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        Auto or standard trans?
         
      • diymirage

        diymirage HP@idle > hondaHP@redline FABO Gold Member

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        ..

        download_20160426_090731_dc7be8b7bc892942d6431fbcdbe2aa7df5877c49.jpg
         
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        • TrailBeast

          TrailBeast Slightly Twisted Member

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          If an automatic the VERY FIRST thing to check is the converter bolts.
          It's common for loose bolts on the converter to sound like a knock, AND really common for it to go away after the converter starts warming up.

          If a stick, flywheel bolts can come loose and sound like a engine knock.

          If that ends up being what it is blue Loctite keeps that from happening again. (usually):D
           
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          • Vamisk

            Vamisk Well-Known Member

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            While you're there, check for wasted lifters. Seems like every chevy I own develops a tick that goes away after about 10 min of driving
             
          • stixx

            stixx Well-Known Member

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            Well, a clanking sound sure is different than a tick from a lifter?
            OP needs to describe better... where does it originate, give us an audio...
             
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            • oley340

              oley340 Active Member

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              Thanks guys gives me a lot to look at
               
            • oley340

              oley340 Active Member

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              I will check that Thanks
               
            • oley340

              oley340 Active Member

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              Turned out to be the harmonic ballancer had seperated thanks for all your help.
               
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              • nm9stheham

                nm9stheham Well-Known Member

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                Glad you caught that? Is this the original one, or do you know the brand?