Piston Installation Trouble

Discussion in 'Small Block Tech' started by BuickGSBanditz, Nov 7, 2012.

  1. I am trying to install some pistons into a buick 350 but I am using a piston ring compressor rental tool from AutoZone and I am having trouble getting them in. As soon as I get to the first ring it pops out. Is there any tips or advice on how to avoid this problem?Or could someone list the steps on how to so I can check if I am missing a step or I am doing something wrong? Or is there a better tool that is highly recomended?
     
  2. pmuller9

    pmuller9 Well-Known Member

    The best tool is a Tapered Ring Compressor made for the specific bore size.
    If you are .030" over then it would be a 3.830 compressor.

    http://www.cnc-motorsports.com/arp-tapered-ring-compressors-3-830.html

    What did you set the ring end gaps at?

    Paul
     
  3. I am looking for a 3.840. That is my bore size. I have looked for one but I cannot fiind my size. If anyone has any info, please let me know. Thanks.
     
  4. pmuller9

    pmuller9 Well-Known Member

    Last edited: Nov 8, 2012
  5. DEADMANSCURVE

    DEADMANSCURVE my first word : truck

    performance tool #W80574 . about $12.00 at summit racing . yeah theres better/more expensive ones but a pretty decent mechanic i worked with liked 'em and my 350 pistons slid right in fine . easy to adjust/use . same or similar models are available in most auto parts places i think .
    and as a side note : you can't really "ease" the pistons down in , the compressor needs to be nice and snug making sure the rings are all the way in past the sides of the piston , oil the rings and slides and cylinder walls good , get the piston and rod assy nice and square against the block surface ( firm n steady ) , grab a med ball peen hammer and tap that piston down in quick n solid using the end of the hammer handle . thats how i was sorta taught . and "before!!!" you do all that be sure your assy is correctly oriented for position and reference/direction marks . and be sure to cover your rod bolt end etc so the cylinder walls and crank are not "nicked" on the way in .
     
  6. well i installed all my pistons using an adjustable tapered ring compressor and was easier than all the others i used, but after installing i noticed that there was a dark mark verticaly along the cylinder. The mark isnt deep enough for a fingernail to feel, does anyone know what these marks mean? Or an=m i beaing overly concerned? and also i am getting about 40 pounds of torque to the crank with all 8 pistons.
     
  7. pmuller9

    pmuller9 Well-Known Member

    What clearence did you set your piston ring end gap?

    Paul
     
  8. all were pre-set at around .019 and i had double checked just to be sure.
     
  9. heres a picture of the mark
    PICT1397.JPG . PICT1400.JPG
     
    Last edited: Nov 11, 2012
  10. gstewart

    gstewart Well-Known Member

    that may translate into "ouch"!
     
  11. Houndogforever

    Houndogforever Silver Level contributor

    I'm wondering what ring gaps should be set at on a buick 455.
     
  12. pmuller9

    pmuller9 Well-Known Member

    Measure down the bore to see which ring it corresponds to.
    We have had trouble lately with the 2 rails on the oil ring pack.
    Double check the end gap on the rails and also check to see if there might be a high spot at the gap end.
    We had a set where the rail was wider at the end and was digging into the wall.

    Make sure there isn't any sharp edges at the ends.

    In general scrutinize every aspect.

    .019 gap is good for a 350 and can actually be as low as .017 for N/A application.


    Paul
     
    Last edited: Nov 11, 2012

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