SAFARI

47 4 DLT ENGINE REMOVAL, INSTALLATION AND MACHINING OF CYLINDER LINERS In order to obtain optimumperformance of engine after reconditioning with liner fitment, we are giving below the machining procedure to be adopted in the field. The disassembled cylinder block should be pressure tested as per the procedure. The block with cracks should be discarded. REMOVAL 1. Keep cylinder block upside down on hydraulic press such that bore from which liner is to be removed lies clear in machine table slot. 2. Ensure that the block is resting squarely on machine bed. 3. Press out liners individually using drift, 2654 5890 01 03 and a suitable distance piece between press ramand the drift. Make sure that the distance piece is also seating squarely between the drift and the ram. INSTALLATION OF LINERS IN CYLINDER BLOCK Thoroughly clean bores of the cylinder block. Thoroughly clean liners. Place cylinder block on hydraulic press ensuring that oil sump mating face is resting evenly and squarely on the horizontal bed. DO NOT SMEAR CYLINDER BORE OF BLOCK OR LINER OUTSIDE SURFACE WITH OIL. Place liner with proper orientation (matching minimum / maximum ovality axis) in the cylinder bore and make it at right angles to cylinder block top surface in longitudinal and crosswise directions using precision tri-square. Press liner using drift 2654 5890 01 02. Use a wooden spacer about 100 mm thick between press ram and drift. Pressing force should be within 4 to 6 tonnes. Similarly, press all other liners. Liners damaged during installation should be removed and replace with new ones. BORING OF CYLINDERS : The cylinder liners are semifinished and it is necessary tomachine the liners to 82.915 to 82.945mmdiameter. NOTE : It is very important that the axis of the bores are parallel to each other and are at right angle to the axis of crank shaft. Permissible shift in perpendicularity of bore from crankshaft axis when checked at 200 mm from crank shaft centre line is 0.040 mm. Therefore we recommend the use of pillar type boring and honing machines. If portable boring bar is used check and clean mating surface of boring bar and cylinder block and centralise the boring bar as accurately as possible in the bore. 4 DL CYLINDER BLOCK HONING 1. PRE-MACHINING CONDITION : Before Honing a) After boring the barrel bore the stock (75 to 95 microns material) must be available for bore honing option. b) Centre line of these bores may be 0.04mm inclined maximum in the longitudinal axis of block (crank bore) c) After boring taper and ovality should be within 15 um max. Surface finish 2.2 to 2.8 uRa or more. 2. CYLINDER BORE HONING : 2.1 Rough Honing : With vertical honing machine operation to be carried out with coolant "HONILO 480" honing oil or kerosene. Flooded coolant to be used so that component bore distortion should not take place. Make the operation gently. Keep the 15 microns/ 20microns stock for Base and Plateau honing. Maintain the taper and ovality within 8 to 10 microns max. Most preferable is within 5micronsmax. Surface finish value at this generation must be 0.8 to 1.2 µm Ra. Machining Data : RPM of Spindle - 100 Fig. 76