Scratch in cylinder

Discussion in 'Engine Topic' started by silver68, Jan 16, 2010.

  1. silver68

    silver68 Member

    37
    0
    Oct 18, 2009
    Sebring, FL
    My engine refresh just keeps getting more aggrevating and more expensive. I just wanted to freshen up my shortblock to put on my dart heads and new intake. Had the block cleaned, new freeze plugs cam bearings and a ball hone.. Looking at at cylinder wall on number one hole and have a scratch still going up about 3/4 of the way up and next cylinder one not as bad going up about half. Its enough to cath a nail on. No ridge on top of cylinder so I thought I would be Ok with just a garage rebuild. Now Im thinking if I should go up to the next overbore size wich would be 40 over. Will the new iron rings seat with these scratches or am I going to have oil smoker.
     
  2. a550550

    a550550 Veteran Member

    607
    0
    Oct 20, 2008
    minnesota
    if you can catch it with your fingernail, it needs to come out. You need to check cylinder size and taper. If the clearance is too much now, it will need a bore.

    You can check that by putting the ring in, and measure end gap. Use the piston to push the ring in level at different areas of the cylinder, measure the end gap, and compare it to the sheet that comes with the rings. Getting the scratch out will do no good if the cylinder taper is over spec already.
     
  3. pdq67

    pdq67 BANNED

    10,496
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    Jul 26, 2001
    Columbia, MO, USA
    Imho, ball-hone it and go!

    pdq67
     
  4. markw

    markw Veteran Member

    816
    0
    Jun 6, 2009
    Illinois
    X2 Think of the area of the scratch ( width x depth). It will fill in with carbon and disappear. Don't worry about it.
     
  5. silver68

    silver68 Member

    37
    0
    Oct 18, 2009
    Sebring, FL
    put in a new hasting ring and measured gap
    top .022
    mid .021
    bottom .020

    piston to wall gap .006 (top of bore)

    Could I get away with trying to ball hone out the scratch and try to even out cylinder taper.

    [​IMG]
     
    Last edited: Jan 16, 2010
  6. markw

    markw Veteran Member

    816
    0
    Jun 6, 2009
    Illinois
    Ball hone is a surface conditioner only. It won't remove enough material to measure. Any idea what made the scratches? Are the pistons OK?
     
  7. silver68

    silver68 Member

    37
    0
    Oct 18, 2009
    Sebring, FL
    bought this shortblock used. Looked like the cam gear made contact on the block and got metal in the oil. Had some scoring on the crank, had to go 10 under on it. Engine ran good, just took it to the strip, but just wanted to freshen it and found this.
    Pistons look ok without alot of wear, just cheap cast flat tops so no big deal to replace if I have to overbore.
     
  8. z28rod

    z28rod Veteran Member

    4,473
    0
    Apr 30, 2009
    hopewell junction,ny
    i would just give it a hone and new moly rings and run the crap outta her..
     
    Last edited: Jan 17, 2010
  9. silver68

    silver68 Member

    37
    0
    Oct 18, 2009
    Sebring, FL
    put a hone on the cylinders that were scratched, actually noticed a couple more. Im going to put it together and see what happens.
     
  10. CNC BLOCKS

    CNC BLOCKS Veteran Member

    1,603
    1
    Oct 11, 2004
    NORTHEAST

    No such thing as chrome moly rings
     

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