Refinishing Cylinder Walls

DESCRIPTION
Honing is only recommended for refinishing cylinder walls when no cross-hatch pattern is visible on cylinder walls or for fitting pistons (6108) to the specified clearance. The grade of hone is determined by the amount of metal to be removed. Follow the instructions of the hone manufacturer. If coarse stones are used to start the honing operation, leave enough material so that all hone marks can be removed with the finishing hone which is used to obtain the proper piston clearance. After honing, thoroughly clean cylinder bores with a detergent and water solution.

WARNING: DO NOT ALLOW THE HONE TO COME OUT OF THE CYLINDER BORE WHILE IT IS TURNING. THE STONES COULD BE RELEASED AND CAUSE PERSONAL INJURY.

CAUTION: After the final operation in either of the two refinishing methods described and prior to checking the piston fit, thoroughly clean with a detergent and water solution and oil the cylinder walls or rusting of the cylinder bores may occur.

NOTE:
Only experienced technicians should perform this work.

PRE-STRESSING THE BLOCK
Before any cylinder is refinished, all main bearing caps must be in place and tightened to the proper torque so that the crankshaft bearing bores will not become distorted from the refinishing operation.

REFINISH DIMENSION
Refinish the cylinder to within approximately 0.038 mm (0.0015 inch) of the required oversize diameter. This will allow enough stock for the final step of honing to obtain the correct surface finish and pattern. For the proper use of the refinishing equipment, follow the manufacturer's instructions.

EQUIPMENT AND USAGE
Cylinder Hone
Use a motor-driven, spring pressure-type Engine Cylinder Hone Set T73L-6011-A and hone at a speed of 300-500 rpm. Hones of grit sizes 180-220 will normally provide the desired bore surface finish of 0.20-0.60 (millimicron) per cylinder in production and 0.30-0.51 (millimicron) average for all cylinders.

Lubricant
When honing the cylinder bores, use a lubricant mixture of equal parts of kerosene and clean engine oil meeting Ford specification WSS-M2C153-F. Operate the hone to produce a cross-hatch finish on the cylinder bore. The cross-hatch pattern should be at an angle of approximately 30° to the cylinder bore. Mark the pistons to correspond to the appropriate cylinders. When the refinishing of the appropriate cylinders has been completed and all pistons are fitted, thoroughly clean the entire cylinder block and oil the cylinder walls.

SELECTING CYLINDERS TO REFINISH
- Cylinder walls that are severely marred and/or worn beyond the specified limits should be refinished.
- Refinish cylinders that are deeply scored, out-of-round, or if the taper exceeds the specification.
- If the cylinder walls have minor surface imperfections, but the out-of-round and taper are within limits, try removing the imperfections by honing the cylinder walls and installing new service piston rings if the piston clearance is within specification.
- Refinish only the cylinder or cylinders that require it. All pistons are the same weight, both standard and oversize; therefore, various sizes of pistons can be used without upsetting engine balance. Refinish the cylinder with the most wear first to determine the maximum oversize. If the cylinder will not clean up when refinished for the maximum oversize piston recommended, replace the cylinder block.