Engine Piston Wear

Discussion in 'Fox 5.0 Mustang Tech' started by McDirty, Feb 20, 2014.


  1. McDirty

    McDirty Member

    Joined:
    Jan 22, 2014
    Messages:
    40
    Likes Received:
    1
    Trophy Points:
    9
    Location:
    Camano Island Washington
    I may have posted this twice.
    i finally got around to tearing apart my engine and it appears that i had a forged 347 stroker. I looked at the pistons and noticed some "wear" marks and am wondering if this is normal, or is it bad and if so can it be fixed 20140219_205201.jpg
     
    #1
  2. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,745
    Likes Received:
    383
    Trophy Points:
    134
    Location:
    Dublin GA
    How many pistons have this problem? All of them or just 1 or 2?
    The marks look like they are from dirt or abrasive material in the oil.
    What do the cylinder walls look like? Can you see any scratches, or is the swirl pattern from honing the cylinders still visible? With stock engine 5.0's, the hone marks are often still visible on high mileage engines.
     
    #2
  3. McDirty

    McDirty Member

    Joined:
    Jan 22, 2014
    Messages:
    40
    Likes Received:
    1
    Trophy Points:
    9
    Location:
    Camano Island Washington
    All pistons look like this and cylinder walls.
     
    #3
  4. madspeed

    madspeed Colonel Mustard Mod Dude Founding Member

    Joined:
    Nov 30, 1999
    Messages:
    8,441
    Showcase:
    9
    Albums:
    1
    Likes Received:
    1,225
    Trophy Points:
    174
    Location:
    a van down by the river
    somebody run sand through that thing? :shrug:
     
    #4
  5. madspeed

    madspeed Colonel Mustard Mod Dude Founding Member

    Joined:
    Nov 30, 1999
    Messages:
    8,441
    Showcase:
    9
    Albums:
    1
    Likes Received:
    1,225
    Trophy Points:
    174
    Location:
    a van down by the river
    haha, just noticed your username. Looks like this engine has run Mc Dirty
     
    #5
    Last edited: Feb 24, 2014
    McDirty likes this.
  6. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,745
    Likes Received:
    383
    Trophy Points:
    134
    Location:
    Dublin GA
    I hope you have enough meat left in the block to take a .040 over stock rebore. That might clean things up enough to save the block, but only the machinist will be able to tell.The pistons are scrap, and so are the rings.
     
    #6
  7. McDirty

    McDirty Member

    Joined:
    Jan 22, 2014
    Messages:
    40
    Likes Received:
    1
    Trophy Points:
    9
    Location:
    Camano Island Washington
    The picture makes it looks worse that it really is. I took it to a shop and I was told they are fine. More than likely what happen, something got in the oil and made some wear marks. I talked to JE pistons and got the measurements of what the pistons should be and the tolerance allowed for the pistons and piston to wall distance. Everything is still within tolerance
     
    #7
  8. Gearbanger 101

    Gearbanger 101 Straight Outta Locash Super Mod

    Joined:
    Aug 11, 2002
    Messages:
    14,468
    Likes Received:
    934
    Trophy Points:
    164
    Location:
    Ontario, Canada
    Higher wear on the pistons and cylinder is normal with a 347....despite what some claim. The 347's lower rod ratio puts greater side load on the piston skirts an cylinder walls because of it's more exaggerated rod angle. This creates an increase friction (in comparison to standard bore/stroke 302) that causes premature wear to these area's. Nature of the beast. It's a trade off us stroker guys have to live with for those bigger power levels.
     
    #8
    88LX5.Oh and McDirty like this.

Share This Page