Chevy Rebuild

Discussion in 'Gas Engines' started by mikealston2428, Jan 17, 2013.

  1. mikealston2428
    Joined: Jul 2011
    Posts: 203
    Likes: 1, Points: 18, Legacy Rep: 10
    Location: aussie

    mikealston2428 Senior Member

    Hi All,
    I am rebuilding a small block Chev 350.
    The pistons are Hypatec, the bore and rings are 0.30
    I have set all the ring gaps.
    I have new 0.40 Clevette 77 conrod bearings.
    I am almost ready to install the pistons.
    My question is, all the pistons have .030 stamped on the top thats fine.
    They all have a small groove on one side, is this groove to go to the front of the engine ?
    They all have 2 stamped on the top and 1 - 8 on the rods and end caps.
    Is the 1 - 8 the firing order the pistons are installed, when i pulled them out they were not in this order.
    Any help would be great.

    Thanks,
    Mike.:confused:
     
  2. Frosty

    Frosty Previous Member

    I would call the supplier and ask them.

    Did you grind the crank. If so then its all new mating surfaces. But yes I would put rods as firing order. Ie 1-5 2-6 3-7 4-8 but it doesnt matter if its all new.

    Don't forget to protect the crank journals with some rubber pipe on the rod studs.

    Your 30 thou over size --they should have been set --what did you set the ring gaps to?
     
  3. mikealston2428
    Joined: Jul 2011
    Posts: 203
    Likes: 1, Points: 18, Legacy Rep: 10
    Location: aussie

    mikealston2428 Senior Member

    I have ground the crank, was told the top ring gap 0.16 and secound 0.18 going to check these on Saturday before install
     
  4. mikealston2428
    Joined: Jul 2011
    Posts: 203
    Likes: 1, Points: 18, Legacy Rep: 10
    Location: aussie

    mikealston2428 Senior Member

    Sorry should have said haven't ground the crank
     
  5. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 491, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The notch faces the front of the engine. The piston/rod assemblies are labeled in sequential order from front to back. Ring gaps are measured in both end gap and side clearance. These measurements are engine family specific (which generation small block), but generally the first gen small block ring side clearance is .0012" to .0032" with a .0042" service limit, while the second gen small block has a top and second ring spec (slightly tighter) and a smaller service limit. All first gen small blocks have top, second and oil ring end gap specs that can differ slightly, depending on the year and output. The same is true of second gen, but not to the same degree.

    Simply put, these are common and general rebuilding practices, covered in any shop manual. The actual specs (again) are usually engine family and/or year specific, so get a manual and look them up. It's also important to follow standard assembly procedures, such as ring gap "clocking" and other techniques, if you want good service from this puppy. First gen small blocks, have a mechanical fuel pump allocation on the front lower right side of the block, while second gen have no fuel pump provision and this is a quick way to tell the difference. Use the engine's serial number to determine the year and type engine it is.
     
    1 person likes this.
  6. Frosty

    Frosty Previous Member

    Whats going on here? 018? is that mm or Inch.

    Par has given you side clearences of 1.2 thou,--this is not the ring gap you asked for.

    If you set ring gap at this your will seize
     

  7. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 491, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I didn't offer end gap clearances, because they can vary quite a bit, depending on output, engine type, etc. Any shop manual for the engine he's got will cover the end gap, which is usually in the .016" range. Typically the compression rings are .010" to .020" with a service limit of .035". Oil control rings are usually .015" to .035", but this can range up to .060" or down to .029", so he'll need to look up the specs for the engine he has. Lastly using side clearance specs for the end gaps will screw up any one, regardless of engine, don't you think Frosty.
     
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