Almost Perfect Block Okay to Use??

Small Block Mopar Engine

  1. 72DMag

    72DMag Well-Known Member

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    Received the 5.9 block back from the machine shop. I already the the pistons and rod here and assembled. machinist said the block just neded honed no need to bore it. Well he was almost right or maybe I'm wrong. All cylinders look great but there is one indented scratch on one cylinder and it does catch my finger nail. But it doesn't catch my finger nail all the time and I need to be at an angle for it to catch.

    Would this be an issue because the motor is going to see track use? Is there anything I can do to make sure it won't be a problem? I tried a ball hone on it and I'm pretty sure that did nothing. Maybe try a stone honing tool or something? I hate to bore it over because of this especially when it turned out with a super nice cross hatch!

    Pics are below you can see that it is a deep mark on the cylinder wall.

    20210410_202904.jpg

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    20210410_203102.jpg

    20210410_203236.jpg
     
    Last edited: Apr 10, 2021
  2. RustyRatRod

    RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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    5.8?
     
  3. pishta

    pishta I know I'm right....

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    Run it. That's my vote. Doesn't look that bad, seen far worse on non smoker strong runners.
     
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    • 72DMag

      72DMag Well-Known Member

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      @RustyRatRod 5.9 sorry that was my typo and it's been corrected.

      @pishta I'm not too concerned if it smokes. More concerned of the moly rings catching it and creating an issue.
       
    • RustyRatRod

      RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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      I didn't think that looked like a 351 Ford. lol
       
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      • RustyRatRod

        RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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        But I agree, run it. It's in one spot. Might be different if it was a long vertical gash.

        Somehow that didn't sound right.
         
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        • 72DMag

          72DMag Well-Known Member

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          • pishta

            pishta I know I'm right....

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            If its a scratch, dress the high side with a stone. The ring wont catch on a divot...its an easy test to push the ring pack past it.
             
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            • Phreakish

              Phreakish Well-Known Member

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              If it's been honed over, shouldn't be any high spots, but may be a sharp edge.

              I agree, push a ring past it and see if you can feel it with the ring. Probably not. But I might also worry what created the divot. Must have been there before, I'd guess? Or was the engine damaged in any way?
               
            • Oldiron440

              Oldiron440 Well-Known Member

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              Run it!
               
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              • Bewy

                Bewy Well-Known Member

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                If it is high enough in the bore that the rings pass over it, I would be worried the end of the oil ring rail could catch on it. It has two rails to choose from...
                 
              • George Jets

                George Jets 1967 Dart 2 Door FABO Gold Member

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                All of the high compression pressures are on the upper half of the cylinders. Much more critical up there.

                Run It . . .
                 
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                • JBurch

                  JBurch FABO Gold Member FABO Gold Member

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                  What color is the "scratch"? Looks like rust to me, hope it is not. That "scratch" could be a crack. I know it's odd; if it is a crack; that it is horizontal, they normally run vertical.
                  It's an idea, hope I'm wrong on my "guess", just one more opinion of the many you will receive here.
                   
                • krazykuda

                  krazykuda Well-Known Member FABO Gold Member How-To Section Editor

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                  You said long vertical gash... :D
                   
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                  • Mopar Sam

                    Mopar Sam Well Fed Member

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                    Run it! Worry about something else, like what's for supper.
                     
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                    • Dartnut

                      Dartnut Don't hate me because i'm beautiful

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                      X2
                      lol
                       
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                      • Professor Fate

                        Professor Fate Push the button, Max...

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                        Which cylinder is it (hard for me to tell from the pics), and where is the "scratch" oriented? I'd run it and not worry about it *UNLESS* it's at the front of #1. If it is, be careful- it could be an indication that someone used too long of a timing cover bolt and cracked a cylinder wall.
                         
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                        • Krooser

                          Krooser Building Chinese Free Engines since 1959...

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                          Run it...
                           
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                          • Dave_J

                            Dave_J Well-Known Member

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                            I have seen this. And it was midway down the bore of #1.
                             
                          • durango r/t

                            durango r/t New Member

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                            Rebuilt the 5.9 in my durango r/t about 9-10 months ago along with the tranny and transfer case as the durango had 304,987 miles on it. Never been rebuilt and the cylinders were perfect,no ridge and full cross hatch top to bottom..The bearings had 2000 on them as my durango is a 2000.The tranny is why i rebuilt it,the bearing and rings looked good
                             
                          • MOPAROFFICIAL

                            MOPAROFFICIAL FABO Gold Member FABO Gold Member

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                            Run it.
                            Seen worse.
                            Vertical as well, still ran it and no issue.
                             
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                            • mygasser

                              mygasser FABO Gold Member FABO Gold Member

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                              and if the dog's gonna eat it before you get to cook it :rofl:
                               
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