Honing Procedure

Important:  Always remove all bearings and components from engine block before cleaning, boring or honing the engine block.

1. When honing the cylinders, follow the manufacturer's recommendations for equipment use, cleaning, and lubrication.
   • Use only clean, sharp stones of the proper grade for the amount of material you remove.
   • Dull, dirty stones cut unevenly and generate excessive heat.
   • Do not hone to a final grade with a coarse or medium-grade stone.
   • Leave sufficient metal so that all stone marks may be removed with fine grade stones.
   • The re-honed surface finish should be 0.25-0.50 micrometer (10-20 micro-inch).
   • Perform final honing with a fine-grade stone and hone the cylinder in a cross hatch pattern at 20 to 30 degrees to obtain the proper clearance.
2. During the honing operation, thoroughly clean the cylinder bore.
   • Repeatedly check the cylinder bore for fit with the selected oversized piston.
   • All measurements of the cylinder bore should be made with the components at normal room temperature.
3. To eliminate taper in the cylinder, when honing, make full strokes of the hone in the cylinder. Repeatedly check the measurement at the top, the middle, and the bottom of the bore.
   • The finish marks should be clean but not sharp.
   • The finish marks should be free from embedded particles and torn or folded metal.
4. When finished, the reconditioned cylinder bores should have less than or meet the specified out-of-round or taper requirements.
5. After final honing and before the piston is checked for fit, clean the bores with hot water and detergent.
   1. 5.1. Scrub the bores with a stiff bristle brush and rinse the bores thoroughly with hot water. Do not allow any abrasive material to remain in the cylinder bores.
      • Abrasive material may cause premature wear of new piston rings and cylinder bores.
      • Abrasive material will contaminate the engine oil and may cause premature wear of the bearings.
   2. 5.2. After washing the cylinder bore, dry the bore with a clean shop towel.
6. Perform final measurements of the cylinder bore.
7. Permanently mark the piston for the specific cylinder to which it has been fitted.
8. Apply clean engine oil to each cylinder bore in order to prevent rusting.