Assemble the engine in the following order:
- - clean all mating surfaces of the block from gaskets stuck and torn during disassembly;
- - fix the cylinder block on the stand, unscrew the oil channel plugs from the front and rear ends and blow out all the oil channels with compressed air.
Put the plugs back in place.
If the clutch housing needs to be replaced or it is installed on the block after repair, it is necessary to first remove two dowel pins from the block, then bolt the crankcase to the block.
A crankshaft is installed in the block on the extreme liners, to the flange of which the indicator stand is attached.
Rotating the crankshaft, check the runout of the hole for the centering shoulder of the gearbox, as well as the perpendicularity of the rear end of the clutch housing relative to the axis of the crankshaft, as shown in the figure.
The runout of the crankcase hole and the end should not exceed 0.3 mm, the end - 0.15 mm.
If the runout of the hole exceeds the specified value, then loosen the bolts and lightly strike the crankcase flange to achieve its correct installation.
After tightening the bolts, the holes for the dowel pins in the crankcase and block are reamed to repair size. Blackness in the holes is not allowed.
After that, pins are pressed into the holes, the diameter of which is 0.015-0.051 mm larger than the holes.
The runout of the crankcase end is eliminated by scraping.
It should be borne in mind that during the above check it is necessary to use a non-worn crankshaft and liners, which must be removed after replacing the crankcase;
- - replace defective cylinder liners with new ones as follows:
- - a) using a combined puller, press out the old sleeve.
Having inserted the legs of the puller into the engine cylinder, rest the studs 4 against the block and push the legs apart with the expanding bolt 5. Then, turning the screw 7, press the sleeve out of the cylinder;
- - b) thoroughly clean the seating surfaces and sealing surfaces on the sleeve and on the block from scale and corrosion;
- - c) insert the repaired sleeve with soft copper gasket into the cylinder from which it was removed.
The sleeve should enter the cylinder freely, effortlessly and protrude above the plane of the block by 002-010 mm. It is more convenient to first check the amount of liner sinking in the cylinder without a gasket.
Drowning should be within 0.20 - 0.25 mm;
- - d) fix the sleeve with a holder so that it does not fall out;
- - cut off two packings of the crankshaft rear seal (120 mm long each) from the cord, put them in the block and holder;
- - re-assemble the crankshaft, to do this, unscrew all the plugs of the dirt traps of the connecting rod journals and remove deposits from them.
Rinse and blow out the oil channels and cavities of the dirt traps with compressed air, tighten the plugs with a torque of 38-42 Nm (3.8-4.2 kgcm);
- - check the condition of the working surfaces of the crankshaft. Nicks, burrs and other external defects are not allowed;
- - press the ball bearing 80203 AC9 with two protective washers into the rear end of the crankshaft. it is allowed to use a 60203A bearing with one protective washer, while 20 g of Litol-24 grease must be placed in the bearing cavity
- - screw the flywheel to the crankshaft.
Tighten the nuts to a torque of 76-83 Nm (7.6-8.3 kgcm).
Lock the nuts by bending one of the tabs of the locking plate onto the edge of the nut;
- - screw the clutch pressure plate assembly with the casing to the flywheel, having previously centered the driven disc using a mandrel (you can use the input shaft of the gearbox) along the hole in the bearing in the rear end of the crankshaft.
The marks stamped on the pressure plate housing and on the flywheel near one of the holes for the housing mounting bolts must be aligned. Tighten the bolts with a torque of 20 - 25 Nm (2.0-2.5 kgcm).
- - the crankshaft, flywheel and clutch are balanced as an assembly, and therefore, when replacing one of these parts, dynamic balancing should be performed by drilling metal from the flywheel
Balancing the crankshaft, flywheel and clutch assembly should not begin if the initial imbalance is greater than 200 gsm. In this case, it is necessary to dismantle the assembly and check the balancing of each part.separately
- - put on the first main journal of the crankshaft the rear washer of the thrust bearing with an antifriction layer to the cheek of the crankshaft;
- — crimp the packing of the crankshaft rear seal in the block and holder with a mandrel
- - wipe the main bearing shells and their beds with a clean cloth. Install liners in bed;
- - lubricate the main bearing shells and crankshaft journals with clean engine oil and lay the crankshaft in the cylinder block;
- - put the main bearing caps on the block studs so that the fixing protrusions on the upper and lower liners of each cap are on the same side, and the numbers stamped on the caps correspond to the bed numbers.
When installing the front main bearing cap, the tab of the rear washer must fit into the groove of the cap.
The end of the front bearing cap must be in the same plane as the end of the cylinder block;
- - put the main bearing caps in their places by lightly tapping with a rubber mallet, the caps should enter the grooves of the cylinder block beds;
- - put washers on the studs, screw on the nuts, apply 2-3 drops (0.06 g) of Unigerm-9 sealant on the threaded part of the nuts and evenly tighten the nuts.
The final tightening must be done with a torque wrench with a torque of 100-110 Nm (10-11 kg/cm). If there is no sealant, then locking the nuts can be done with a locking plate 24-1005301-01;
- - install rubber gaskets in the grooves of the packing holder and coat their side surface protruding from the groove with soapy water. Reinstall the holder and tighten the nuts;
- - rotate the crankshaft, which should rotate freely with little effort.
You can rotate the crankshaft using the flywheel or using a device consisting of the input shaft of the gearbox with a square wrench welded to it or a handle with a square hole.
The device can also be used for centering when setting the clutch disc;
- - put the front washer of the thrust bearing with the anti-friction layer out so that the pins pressed into the block and the cover fit into the grooves of the washer;
- - put on a steel thrust washer of the crankshaft with a chamfer in the inner hole towards the front washer of the thrust bearing;
- - press the crankshaft gear to the stop and check its axial clearance.
The check is carried out as follows: put a screwdriver (knob, hammer handle, etc.) between the first shaft crank and the front wall of the block and, using it as a lever, press the shaft to the rear of the engine.
Using a feeler gauge, determine the clearance between the end face of the thrust bearing rear washer and the shoulder plane of the first main journal. The gap should be within 0.125-0.325 mm;
- - sub-assembly of the connecting rod and piston group.
Clean the piston crowns and piston ring grooves from carbon deposits.
When replacing pistons, liners, piston pins or connecting rods, subassembly of mating pairs should be carried out at a temperature of the parts (20 ± 3) ° C.
Pistons of the same size groups as the sleeve must be installed in bored or new liners.
Selection from neighboring groups is allowed, while, as with the selection of pistons into working sleeves, the selection is made according to the pulling force of the probe tape with a thickness of 0.05 mm and a width of 10 mm.
The probe tape is placed in a plane perpendicular to the axis of the piston pin, along the largest diameter of the piston. The force on the dynamometer connected to the probe tape should be 35-55 N (3.5-5.5 kgf);
- pick up the piston pin to the connecting rod so that it fits tightly into the connecting rod hole under the force of the thumb, moves freely, without jamming and does not fall out under the action of its own weight when the axis of the connecting rod hole is located at an angle of 45 ° (approximately).
Piston pin and connecting rod must be the same or adjacent size group.
When picking up, the piston pin should be lightly lubricated with engine oil. Dimensional grThe piston and piston pin groups must match.
Piston with piston pin, piston rings and connecting rod assembly must be weight controlled. The difference in mass per engine should not exceed 12 g;
- press the piston pin into the piston and connecting rod using a tool. At the same time, heat the piston to a temperature of 60 - 88 ° C, lightly lubricate the piston pin with engine oil.
Connect the piston with the guide mandrel 3 to the connecting rod, put the piston pin on the thin end of the mandrel, as shown in the figure, put the thrust bearing 5 on the pin and screw the pin in place with the screw 6.
Pressing a pin into a cold piston can damage the surface of the holes in the piston bosses, as well as deform the piston itself.
When placing the piston in the cylinder (by the “FRONT” mark on the piston), the hole for lubricating the cylinder mirror from the lower head of the connecting rod should be facing the opposite side of the camshaft;
- pick up the piston rings according to the cylinder, as shown in the figure.
The gap measured at the joints of the rings should be 03-0.7 mm for the compression rings and 0.3-1.0 mm for the steel disks of the oil scraper ring.
In worn cylinders, the smallest gap is 0.3 mm;
- use a feeler gauge to check the gap between the rings and the wall of the piston groove, as shown in the figure.
Check along the circumference of the piston at several points.
The clearance value should be within 0.050–0.870 mm for the upper and lower compression rings, and 0.135–0.335 mm for the assembled oil scraper ring;
• turn the drive shaft to the position shown in A and place the drive in the block socket.
When inserting the drive into the socket, it is necessary to slightly rotate the oil pump shaft so that the end of the drive shaft enters the hole in the pump shaft.
The drive should slide in without much effort.
In a properly installed drive, the slot in the shaft sleeve should be parallel to the motor axis and offset from the motor, as shown in B;
- - fix the drive;
- - check for clearance in the camshaft and drive gears;
- - lubricate the joints of the lower flange of the cylinder block with the timing gear cover and the packing holder with Elastosil 1Z7-8Z adhesive-sealant or UN-25 paste;
- - install an oil crankcase gasket on the lower flange of the cylinder block;
- - install the oil sump on the studs and secure it with nuts and washers, tightening the nuts evenly;
- - install and bolt the lower part of the clutch housing;
- - clean the combustion chambers and channels of the cylinder head from carbon deposits and deposits, wipe and blow with compressed air;
- - grind the valves using a lapping paste composed of one part M-20 micropowder and two parts I-20A oil.
Before starting lapping, check for warping of the valve disc and burning of the valve and seat.
If these defects are present, it is impossible to restore the tightness of the valve with one lapping, and the seat must first be ground, and the damaged valve replaced with a new one.
If the gap between the valve and the sleeve exceeds 0.25 mm, then the tightness cannot be restored either. In this case, the valve and sleeve should be replaced with new ones.
Valves (for spare parts) are produced in a standard size, and guide bushings are available with an inner diameter reduced by 0.38 mm (to ream them to the final size after being pressed into the cylinder head).
The worn guide bush is pressed out using a mandrel
Valve seats are removed by milling with a carbide countersink.
Repair seats have an outer diameter 0.25 mm larger than standard ones, so the seats for the seats are bored to the following dimensions: for the inlet valve seat - 49.25+0.025 mm, for the exhaust valve - 42 .25+0.025 mm.
Saddle guide sleeves before assembly and must be cooled in carbon dioxide (dry ice), and the cylinder head heated to a temperature of 160-175 ° C. During assembly, the seats and bushings must be inserted into the sockets of the head freely or with slight effort.
The new inlet and exhaust valve bushings are pressed in until they protrude 20 mm above the head; after pressing, expand the bushing holes to a diameter of 9+0.022 mm, and grind the seat chamfers, centering on the hole in the bushing.
When grinding, ensure that the chamfer on the valve seat is concentric with the hole in the sleeve within 0.05mm.
Chamfers are ground at an angle of 45°. The outer diameter of the chamfer at the seat for the inlet valve should be 46.8 mm, and at the outlet - 38.8 mm.
The width of the chamfer should be at the inlet valve seat 1.8 - 2.3 mm., At the exhaust valve - 2.3-2.5 mm.
Chamfer width is obtained by grinding the intake valve seat at 30° as shown in A and the exhaust valve at 15° at B. The chamfer should be the same around the entire perimeter.
After grinding the seats and lapping the valves, thoroughly clean all gas channels and blow with compressed air so that no abrasive dust remains;
- - coat the valve stems with a thin layer of colloidal graphite diluted in engine oil, or lubricate with oil
- - press valve stem seals onto the valve guide bushings, insert the valves into the bushings according to the marks made and assemble them with the springs. Make sure that the crackers entered the annular groove of the valves;
- - rub graphite powder on both sides of the cylinder head gasket and put it on the studs. Install the head and secure it with nuts and washers.
Tighten the nuts with a torque wrench to 83-90 Nm (8.3-9.0 kg/cm) in the correct order
- - clean with a wire and blow out with compressed air the holes in the rocker arms, in the rocker arm axis and adjusting screws, in the fourth main rack of the rocker axle and oil channels in the cylinder head.
Check the tightness of the rocker bushings. In the event of a loose fit during operation, the bushing may move and block the tappet rod lubrication hole. Such bushings must be replaced;
- - perform subassembly of the rocker axis. Before setting each rocker arm, lubricate its bushing with engine oil;
- - insert the pushers into the slots according to the labels on them. Lubricate the tappets and holes in the block with engine oil;
- - insert the rod assembly with tips into the holes in the cylinder head;
- - install the assembled rocker axle on the studs and secure with nuts and washers. Adjusting bolts with their spherical part should lie on the sphere of the upper tip of the rod;
- - set the gaps between the ends of the valve stems and the noses of the rocker arms. The gap between the rocker arms and the first and eighth valves is 0.35-0.40 mm, the gap between the other rocker arms and valves is 0.40-0.45 mm.