TM 5-3805-260-24 BASIC BLOCK When    honing    cylinder    blocks,    maintain    the specific    dimensional    surface    finish    and    cross    hatch tolerances to obtain safisfactory oil control. The tolerances specified are virtually the same as those used for original bore finish at the factory, and can be obtained with  an  automatic  honing  machine  such  as  the  Sunnen CK-I0.    This  machine  has  been  evaluated  and  found  to give satisfactory results. Due  to  the  cost  of  suitable  honing  equipment,  it may  be  more  expedient  to  have  the  honing  done  by  a shop equipped with a Sunnen CK-!O or equivalent. TRANSIT PREPARATION The  following  Steps  can  prevent  damage  to  the block in transit to a shop. 1. Completely disassemble, but do not clean block. The residual oil on the surface will prevent rust. 2. Enclose the block in an industrial plastic bag and position  it  with  the  oil  pan  surface  on  a  suitable wood    pallet    or    equivalent.    Dimension    of    a suitable wood pallet are shown. TRANSPORTING PALLET 3. Cover the block with 1/2 in. (12.7 mm) thick plywood or equivalent, and band block to the pallet. 4. Follow   similar    instructions    when    block    is returned.  To  prevent  rust,  the  block  should not   be   cleaned   after   honing,   the   film   of honing   oil   provides   ample   protection   from rusting. NOTE: If blocks are to be stored for any  length  of  time, clean and anti-rust after honing. CLEANING PROCEDURE After honing is completed, and before assembling    the    engine,    the    cylinder    block    must    be cleaned     and     prepared     according     to     the     following instructions. 1. If not previously removed, the camshaft bearings must be removed to permit thorough cleaning of the  oil  passages.  To  remove  the  bearings,  see the   topic   CAMSHAFT   BEARINGS   REMOVAL AND INSTALLATION. 2. Use   1P3565   Chamfering   Group,   remove   the sharp corner at the bottom of the cylinder bores as  shown.  This  is  essential  to  prevent  scuffing the     piston     skirts.     The     chamfer     should     be approximately 10° x .09 in. (10° x 2.3 mm). CHAMFERING BORE CAUTION Avoid  damage  to  the  cylinder  bore  surface  or  any other parts. 3. Using  the  1P5580  Brush  Group  and  a  strong detergent and water solution, clean the following areas of the block. A. Main  oil  gallery  and  supply  passage.  Use the   IP5572   or   IP5573   Brush   and   stroke several times while rotating the brush. B. Camshaft  bearing  oil  passages.    Use    the 1P5571   Brush   and   stroke   several   times while rotating the brush. C. Cylinder bores. Use the 1P5574 Brush and stroke   each   bore   for   one   minute   while rotating the brush at 1000 rpm. 3-368