TM 5-3825-226-24 BASIC BLOCK When    honing    cylinder    blocks,    maintain    the specific   dimensional   surface   finish   and   cross   hatch tolerances    to    obtain    satisfactory    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-10.  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-10 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 comer 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  1P5573  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. 3-366