The durability of the repaired engine largely depends on the bench run-in and the mode of its operation on the car for the first 6000 km of run

When used for the repair of factory parts, the following break-in mode is recommended:

Cold break-in (at 1200-1500 rpm), min - 15

Hot run-in in idle mode, min, at:

  • 1000 rpm - 60
  • 1500 rpm - 60
  • 2000 rpm - 30
  • 2500 rpm - 15

Adjustment and verification at a speed of rotation up to 3000 rpm is carried out within 15 minutes; when running in, oil with a viscosity of 2.6-4°VU50.

During the break-in, the oil becomes clogged with solid particles - run-in products, to trap which it is advisable to use a separate lubrication system consisting of an oil tank of sufficient capacity, an oil pump driven by an electric motor, a fine oil filter connected in series to the system and capable of passing the entire amount of oil pumped into the engine, and oil heating and cooling systems.

Oil enters the engine through the drain hole of the filter and flows freely through the drain hole of the oil pan into the oil tank, from where, after settling, it is pumped through a special filter to the engine.

It is necessary to maintain the oil pressure before entering the engine at least 4.5 kg/cm2, and the temperature at least 50°C.

The temperature of the water leaving the engine should be 70 - 85°C.

The oil pressure in the oil line on a warm engine should be at low speeds (500 rpm) not less than 0.7 kg/cm2, at 1000 rpm not less than 1.75 kg /cm2 and at 2000 rpm - within 2-4 kg/cm2.

After running the first 1000 km you need to:

For engines ZMZ-402 and ZMZ-4201, tighten the mount:

  • - cylinder heads. Tightening torque of the block head nuts 83–90 Nm (8.3–9.0 kgf m)

Check and tighten the nuts only on a cold engine.

After tightening the nuts, check and, if necessary, adjust the clearances in the valve drive;

  • - racks of the axis of the rocker arms of the valves. Tightening torque for strut nuts 35–40 Nm (3.5–4.0 kgf m).

After tightening the nuts, check and, if necessary, adjust the clearances in the valve drive.

Check and tighten if necessary:

  • - fuel line, pressure reducing valve and power system hoses (engine ZMZ-4062);
  • - inlet pipe and exhaust manifolds (exhaust manifold for the ZMZ-4062 engine) to the cylinder head.

The tightening torque of the fastening nuts for the ZMZ-402 and ZMZ-4021 engines is 40–56 Nm (4.0–5.6 kgf m).

For the ZMZ-4062 engine, the tightening torque of the intake pipe fastening nuts is 29–36 Nm (2.9–3.6 kgf m), and the exhaust manifold nuts are 20–25 Nm (2.0–2.5 kgf m );

  • - flange and brackets for exhaust pipes, as well as all elements of the exhaust system;
  • - a generator and a pulley on its shaft. The tightening torque of the nuts for fastening the generator of the ZMZ-402 and ZMZ-4021 engines is 44–56 Nm (4.4–5.6 kgf m), and the ZMZ–4062 engine is 12–18 N m (1.2–1.8 kgf m).

The tightening torque of the alternator adjusting bar bolt is 12–18 Nm (1.2–1.8 kgf m);

  • - starter.

Tightening torque of the nuts for fastening the starter of the ZMZ-402 and ZMZ-4021 engines 44-62 Nm (4.4-6.2 kgf m), the ZMZ-4062 engine 67-75 Nm (6.7-7.5 kgf m);

  • - crankshaft pulley. The tightening torque of the pulley bolts of the ZMZ-402 and ZMZ-4021 engines is 11–16 Nm (1.1–1.6 kgf m), the ZMZ–4062 engine is 104–128 Nm (10.4–12.8 kgf m);

Check and if necessary:

  • - adjust clearances in the valve drive of ZMZ-402 and ZMZ-4021 engines;
  • - adjust the tension of the fan drive belts of the ZMZ-402 and ZMZ-4021 engines;
  • - the engine speed at idle and the content of CO and CH in the exhaust gases;

Change the engine oil and the oil filter on the ZMZ-4062 engine or its filter element on the ZMZ-402 and ZMZ-4021 engines.

After driving 2000 km you need:

For a new car with a ZMZ-402 or ZMZ-4021 engine, dismantle the throttle washer installed under the carburetor.

Check and, if necessary, tighten all accessible screw connections.

In this case, pay special attention to the fastening of the generator, generator pulley, starter, exhaust pipe of the exhaust system, radiator, engine mounts, clutch drive, brake drive, gearbox, clutch housing, wheels, suspension parts, steering.

Check and adjust if necessary:

  • - ignition timing for engines ZMZ-402 and ZMZ-4021;
  • - the frequency of rotation of the engine crankshaft in idling mode and the contente CO and CH in exhaust gases;

During the subsequent run up to 6000 km, you should also adhere to moderate speeds (up to 90-100 km / h) and avoid driving on heavy roads.