Boring Procedure
- Before honing or boring, measure all of the new pistons.
Select the smallest piston for the piston fitting. Slightly varied pistons
in a set may provide correction, if the first piston is too loosely fitted.
- Before using any type of boring bar, file the top of the engine
block to remove any dirt or burrs. If the cylinder block is not straight,
the boring bar may be tilted, causing the bored cylinder wall to have incorrect
right angles to the crankshaft.
- Carefully follow the instructions furnished by the manufacturer
regarding use of equipment.
- Install all crankshaft main bearing caps to specification when
boring cylinders. Cover or tape the crankshaft bearings and other internal
parts to protect these parts during the boring or honing operation.
- Leave 0.03 mm (0.001 in) on the diameter for finish
honing when performing the final cut with a boring bar. Carefully perform
the honing and boring operation to maintain the specified clearances between
pistons, rings, and cylinder bores.
Honing Procedure
- Follow the manufacturer's recommendations for use, cleaning, and
lubrication when honing the cylinders. Use only clean, sharp stones of the
proper grade for the amount of material to be removed. Dull, dirty stones
cut unevenly and generate excessive heat. When using coarse or medium-grade
stones, leave sufficient metal so all stone marks may be removed with the
fine stones used for finishing to provide the proper clearance.
- During the honing operation, thoroughly clean the cylinder bore.
Check for the correct piston fit.
- Make full strokes in the cylinder to
eliminate taper. Repeatedly check the measurement at the top, the middle,
and the bottom of the cylinder bore.
Notice: Handle the pistons with care. Do not force the pistons through the cylinder
until you hone the cylinder to the correct size. The piston can be distorted
through careless handling.
- When finish honing a cylinder bore to
fit a piston, move the hone up and down at a sufficient speed to obtain a
fine and uniform surface finish in a cross hatch pattern.
- The finish marks should be clean but not sharp. The finish marks
should be free from imbedded particles and torn or folded metal.
- Determine the finish hone cylinder measurement by measuring the
piston to be installed, and by adding the average of the clearance specification.
Measure the block and the piston at normal room temperature.
- True up the refinished cylinder bores. Final hone each cylinder
bore to remove all stone or cutter marks.
- After final honing and before the piston is checked for fit, clean
the bores with hot water and detergent. 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. This abrasive material will wear
the new rings, the cylinder bores, and the bearings lubricated by the contaminated
oil. After washing dry the bore.
- Permanently mark the piston for the cylinder to which the piston
has been fitted.
- Apply clean engine oil to each bore to prevent rusting.