3.25. Dismantling and assembly of the engine

We remove the engine from the car (see. "Removal of the engine from the car") we also clear it of dirt and oil.

Cap key "on 13" we turn off four nuts of hairpins of fastening of an arm of the right forward support of the power unit to the block of cylinders of the engine...

... also we remove an arm.

Similarly we disconnect an arm of the left forward support from the block of cylinders.

On fixing hairpins of the right arm of a forward support we mount a stand plate for dismantling of the engine and we fix the engine at the stand.

We remove the generator, a flywheel, a head of the block of cylinders, a cover of the pump of cooling liquid, the case pallet, a cover, a chain and asterisks of the drive of the camshaft, an oil separator and the oil pump. Operations on dismantle of these knots are given in appropriate sections.

Key "on 10" we turn off two nuts of hairpins of fastening of a flange of the taking-away radiator tube отопителн to a pump housing of cooling liquid...

... also we pick up the phone with sealing laying.

Key "on 13" we turn off three bolts of fastening of a pump housing of cooling liquid to the block of cylinders of the engine.

We remove a pump housing and its sealing laying.

Key "on 10" we turn off six bolts of fastening of a cover of a back epiploon of a bent shaft...

... also we uncover with an epiploon.

Connection is condensed with laying.

Key "on 10" we turn off a bolt of fastening of an arm of a drain tube of an oil separator to the block of cylinders of the engine...

... also we remove an arm.

Head "on 14" we turn off two nuts of bolts of fastening of a cover of a rod (the piston at the same time has to be in NMT).

We uncover a rod.

We take out the lower insert of the conrod bearing from a cover.

We shift the lower head of a rod from a neck of a bent shaft.

Resting the wooden handle of the hammer against the socket of the lower head of a rod, we push the piston in the cylinder...

... also we take out the piston with a rod from the cylinder.

Similarly we take out pistons with rods from other cylinders of the engine.

We take out the top insert of the conrod bearing from a rod head.

We fix a rod in a vice with overlays of sponges from soft metal.

Carefully, without making big effort, we unclench fingers the lock of the top compression ring, we bring a ring out of a flute of the piston and we remove it.

In the same way we remove the second compression ring.

We remove an oil scraper ring and its dilator.

Having installed the piston on a wooden support with cylindrical dredging under a skirt of the piston and an opening under a piston finger, the hammer through a mandrel we beat out a piston finger.

If some details of conrod and piston group are not damaged and a little worn-out, then they can be used again. Therefore when dismantling it is necessary to mark their arrangement to establish on former places.

Before dismantle of a bent shaft we check its axial gap. For this purpose the assembly shovel moved a bent shaft in the axial direction forward against the stop and measure by the flat probe a gap between a cheek of a bent shaft and a persistent half ring. The extreme size of a gap — 0,35 mm.

Head "on 17" we turn off two bolts of fastening of a cover of the radical bearing of a bent shaft...

... also we uncover with the lower insert of the bearing.

We take out an insert from a cover.

Similarly we turn off bolts of fastening and we uncover four more radical bearings.

We take out a bent shaft from beds.

From the protocheck of a bed of the fifth radical bearing we take out persistent half rings.

We take the top inserts of radical bearings from beds of the block of cylinders.

By stripper it is pressed from a sock of a bent shaft a camshaft drive asterisk (operation we carry out carefully not to damage asterisk teeths)...

... also we remove an asterisk.

The hammer through a drift from soft metal we beat out the segment spline fixing an asterisk from a groove of a bent shaft...

... also we take out a spline.


After dismantling of the engine carefully we wash out details in kerosene, we clear of a deposit and resinous deposits and we check their technical condition. Piston rings and fingers, skirts, ring flutes and lugs of pistons should not have cracks, chips, zadir and prizhog. On a mirror of cylinders, radical and conrod necks of a bent shaft cracks are not allowed. The damaged details are subject to obligatory replacement. Teases on necks of a bent shaft we eliminate with grinding, and on a mirror of cylinders — a honingovaniye (on HUNDRED). We define wear of the details which do not have noticeable defects by means of the measuring tool.

We measure diameter of a skirt of the piston by a micrometer with the price of division of 0,01 mm in the plane, a perpendicular axis of a piston finger, at distance of 52,4 mm from the piston bottom.

We measure the internal diameter of the cylinder by a nutromer with the price of division of 0,01 mm.

We take measurements in four belts (at distance of 5, 15, 50 and 90 mm from the plane of the socket of the block and a head of the block of cylinders) and in two directions — along an axis of a bent shaft and perpendicular to an axis.

The assembly gap between the piston and a mirror of the cylinder (a difference between the measured diameters of the cylinder and piston) has to make 0,05-0,07 mm. If the maximum value of a gap is more than 0,15 mm (the extreme size of wear), cylinders should be chiseled and otkhoningovat under the repair sizes of pistons.

The gap on height between a piston flute and a piston ring is checked, having inserted a ring into the corresponding flute and entering the flat probe between an end face of a ring and a surface of a flute.

The extreme size of a gap for each of rings makes 0,15 mm.

We measure a gap in the lock of a piston ring by the flat probe, having installed a ring in that cylinder in which it worked, at distance of 20-30 mm from bottom edge of the cylinder. Gap size for each of rings makes 0,25-0,40 mm.

We measure radical and conrod necks of a bent shaft by a micrometer. If wear or ovality of necks is more than 0,03 mm, it is necessary to proshlifovat necks to the next repair size.

After grinding of necks of a bent shaft it is necessary to wash out oil channels in conrod necks of a shaft, and for this purpose...

... to remove caps of oil channels.

We recommend to carry out grinding of necks of a bent shaft, removal and installation of new caps for HUNDRED.

We wash out and clear oil channels of the block of cylinders of the engine of a deposit, we delete the remains of old laying and sealant and we blow the block compressed air.

We assemble the engine in the return sequence. We establish new inserts of radical bearings of the nominal or repair size in a bed of the block of cylinders: in the first, the second, fourth and fifth - inserts with pro-points on internal surfaces...

... and in the third bed - an insert without pro-point.

We oil working surfaces of inserts engine and we stack a bent shaft in a bed of the block of cylinders.

We insert the persistent half rings oiled by engine into pro-points of the fifth bed: from the forward party - steel-aluminum, with back - ceramic-metal (yellow color).

Surfaces of half rings with an antifrictional covering (on these surfaces flutes for a lubricant supply are executed) have to be turned to surfaces of a bent shaft. Covers of radical bearings are not interchanged as are processed with beds of the block of cylinders of the engine at the same time. The marking of covers corresponding to numbers of radical bearings is applied on external surfaces of covers, as shown in fig. 4.

Fig. 4. Tags on covers of radical bearings of a bent shaft.

We establish the lower inserts (all - without protocheck) in covers of radical bearings and we oil them engine. We establish covers of radical bearings on the places according to tags. At the same time locks of the top and lower inserts have to be from one (right) party of the block of cylinders (looking on the car course). We tighten nuts of fastening of covers of radical bearings the ordered moment (see. "Appendix").

Pistons approach cylinders on classes.

The class of diameter of the cylinder designated by a letter is beaten out on the lower privalochny plane of the block of cylinders.

(Letter) and category of diameter of an opening under a piston finger (figure) to beat out a class of diameter of a skirt of the piston) on the piston bottom.

At the same time alphabetic references on the piston and the cylinder have to coincide.

All pistons installed on the engine have to be one weight group (the difference on the mass of pistons should not exceed 5 g).

The piston finger which is correctly picked up for diameter to the piston (on category } and oiled by engine, has to enter piston lugs under effort of a thumb of a hand and not drop out of lugs in vertical position.

At assembly of a rod with the piston it is heated the top head of a rod at a temperature of 240 °C within 15 min. The heated rod is clamped in a vice, we put on the piston a rod, having provided coincidence of an opening in the top head of a rod and openings in piston lugs.

Quickly we enter the piston finger which is put on a mandrel into openings of the top head of a rod and lugs of the piston.

Operations on a press fitting of a piston finger should be made as fast as possible as after cooling of a rod it will not be possible to change position of a finger in its head any more.

We oil engine ring flutes on the piston and we establish piston rings. At the same time...

... the pro-point ("scraper") of the lower compression ring has to be turned down...

... and facets on an external surface of an oil scraper ring have to be turned up.

If on a ring near the lock the tag "TOP" or "TORAHS" is put, we install a ring on the piston by a tag up.

The rings installed on the piston have to be turned in the flutes freely, without jamming.

We have piston rings on the piston so that locks of rings were at an angle 120 ° on a circle from each other.

We stack new inserts of conrod bearings of the nominal or repair sizes in the lower heads and covers of rods and we oil inserts engine. We grease also mirrors of cylinders, pistons and piston rings. We press out piston rings on the piston a mandrel for installation of the piston with rings in the cylinder and we enter the lower head of a rod and a skirt of the piston into the cylinder. The piston in the cylinder we have so...

... that the tag "П" near a lug was directed forward.

Resting the hammer handle against the piston bottom, we push the piston in depth of the cylinder...

... so far the lower head of a rod { with an insert of the conrod bearing) will not be established on the corresponding conrod neck of a bent shaft. At the same time the conrod neck has to be in HMT.

We establish a cover with an insert on bolts of the corresponding rod.

On side surfaces of a rod and a cover tags which have to coincide and settle down on the one hand are put.

We tighten nuts of bolts of fastening of a cover of a rod evenly ordered moment (see. "Appendix"). Similarly we install pistons with rods of other cylinders.

We carry out further assembly of the engine in the sequence, the return assembly, replacing sealing laying and epiploons new.