1. Installation of the crankshaft
During crankshaft installation, the main bearing bolts should be tightened from thrust gear(the third gear) to both ends in order, and in three steps:
① tighten to 60－80 N.m
② tighten to 160－180 N.m
③ tighten to 220－260 N.m
During every time, the crankshaft should be rotated to check the mobility. It should be able to rotate freely after the final tightening.The axial clearance should be between 0.1 and 0.27 mm.
2. Installations of the piston and the connecting rod
When installing the piston rings, put the surfaces marked upward( the second positive twist ring inner fillet upward). During positioning the piston-connecting rod assembly into the cylinder bore, stagger the joints in turn. And put the arrow marked on the top surface of piston towards the front end of the engine. Remember spreading some clean oil before tightening connecting-rod bolts. The tightening torque should be between 160-200N.m, and completed in three steps:
① tighten to 50－70 N.m
② tighten to 100－120 N.m
③ tighten to 160－200 N.m
3. Installation of the camshaft
Position the camshaft into the cylinder body with caution to make sure not scratch the surfaces of the journals, cams, and liners. And then install the cir clip, cam thrust plate, cam gear, and cam retainer, Finally,tighten fastening bolt with more than 300N.m tightening torque. The camshaft should be able to rotate freely, and its axial clearance is between 0.1-0.2mm.
4. Installation of the valves and valve guides
The valve guides should be pressed in at normal state with 20±0.3mm distances between their top surfaces and the surfaces of the cylinder head spring seats. Both the valve face angles of intake and exhaust valves are 45º. the valves and valve seat inserts should be grind in pair, and checked through kerosene. It must be guaranteed that kerosene do not leak within three minutes. The valve recession heights of the valves should be between 1±0.2mm.
5. Installation of the injectors
Before mounting the cylinder head, the injectors should be installed in the cylinder head first. The nozzles should protrude 3.4±0.1mm from the bottom surface of the cylinder head, which can be ensured by adjusting the width of the injector washer. And then remove the injectors to prepare for following installation. As long as adjusted, the injectors and washers can not be exchanged during installation.
6. Installation of the cylinder head
During cylinder head installation, the cylinder head bolts should be tightened to a tightening torque of between 210-250 N.m, do not finish that in once time and following the sequence shown in the following figure by three steps:
① tighten to 60－80 N.m
② tighten to 120－140 N.m
③ tighten to 210－250 N.m
7. Installation of the gear train
The crankshaft timing gear, injection pump gear, and camshaft gear should all be accordance with the timing requirement, so there are timing marks, which should be aligned during installing the gears, on them and timing idle gear. Oil the tooth surface after installing. The range of the gear meshing clearance is between 0.07-0.25mm.
Caution
1. every component should be cleaned before being installed, especially the oil passages, no dirt is permitted in them.
2. No corrosion, burr, or scratch is permitted on the fit surfaces of every component.
3. Friction surfaces and important fit surfaces should be oiled before installing.
4. Fit clearance( or interference) should be accordance with the requirement offered in the main fit clearance(or interference).
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