During major repairs, diesel engines must undergo cold and hot running-in, acceptance testing, technical inspection, and organoleptic testing
Diesels arriving for running-in and testing must be assembled and adjusted in accordance with the requirements of GOST 18523-79, TURB05786459.096-96 and the technology developed on their basis.
Diesels arriving for running-in and testing must be provided with documents indicating the diesel engine number, fuel pump number, and a note on the performance of control operations during assembly.
Diesels arrive for running-in and testing without a fan, hydraulic pump, liquid and oil radiators. Running-in without a generator using a tension roller is allowed.
The crankshaft should rotate freely by hand, without jamming, when applying a torque of 60-80 Nm.
Before testing, check and adjust the gaps between the rocker arm strikers and the ends of the valve stems.
On a cold diesel engine, the gaps should be: intake valves - 0.25-0.30 (cylinder firing order: 1-3-4-2).
Check and adjust the tension of the liquid pump drive belt on the KI-8920 stand.
The normal deflection of the belt branch from a force of 40±1 N in the section between the pulleys is 12-17 mm.
Check the condition of the external fasteners. Nuts and bolts must be tightened until snug. Diesel engines must be run-in using M-10G or M-10V engine oil, GOST8583-78.
Hot running-in and acceptance tests of repaired diesel engines must be carried out using summer diesel fuel L GOST305-82.
Diesel engines are recommended to be run-in using a centralized lubrication system.
If the repair facility or workshop does not have a centralized lubrication system, 11.8 liters of diesel oil heated to a temperature of 60-75°C must be poured into the diesel crankcase.
The same oil as in the diesel crankcase must be poured into the fuel pump regulator housing, up to the level of the control plugs.
Liquid and gas outlet pipes, as well as fuel pipes of the fuel system must be tightly connected to the corresponding pipes diesel.
The control rod must be connected to the diesel engine and the oil pressure, coolant temperature and oil temperature monitoring devices must be installed.
The diesel fuel system must be filled with diesel fuel.
Cold running-in of the diesel engine
Cold running-in should be carried out for 30 minutes in the following modes:
- 600-650 min -1 - 10 min;
- 750-800 min -1 - 10 min;
- 900-950 min -1 - 10 min.
Running-in of the diesel engine with the injectors removed is not allowed.
During the running-in diesel engines (if there is a centralized lubrication system), it is necessary to maintain the oil pressure in the oil line at least 0.2 MPa at a coolant temperature at the outlet of the diesel engine within 60-75 "C and regularly check the lubrication supply to the adjusting screws of the rocker arms and pusher rods.
Leakage and dripping of fuel, oil and coolant at the junctions of pipelines and joint planes of mating parts are not allowed.
During the running-in, extraneous knocks and noises in the diesel engine are not allowed.
Hot running-in of a diesel engine without load
Before hot running-in, it is necessary to remove air from the fuel system, check and, if necessary, set the angle of the start of fuel supply within the range: for diesel D-245.12 - 18-20 °; for diesel D-245.12S - 10-11°.
The diesel engine should be started by the electric motor of the running-brake stand at a rotation speed of 500-750 min -1.
Hot running-in of diesel engines without load should be carried out for 15 minutes in the following modes:
- 1200 min -1 -10 min;
- 1400 min -1 - 5 min.
The oil pressure in the line should be within 0.25-0.35 MPa at a coolant temperature at the outlet of the diesel engine within 60-90° C.
After hot running-in without load, tighten the cylinder head mounting bolts to a torque of 190-210 Nm.
Check the adjustment of the gaps between the rocker arms and the ends of the valve stems on a warmed-up diesel engine.
Hot running-in of a diesel engine under load
Starting should be carried out using the electric motor of the running-in and brake stand.
Hot running-in of diesel engines under load should be carried out for 30 minutes in the modes given in the table.
During the running-in process, it is necessary to monitor the readings of the oil pressure gauge in the diesel lubrication system, which on a diesel engine warmed up to 75-95 °C should be 0.25-0.35 MPa at the nominal speed and at least 0.08 MPa at the minimum speed.
The oil pressure should be adjusted using the adjusting plug of the drain valve centrifuges.
Slight smoking of a heated diesel engine is not a rejection sign if, during diesel operation, for 5 minutes after removal of the I load no oil emission is observed in the exhaust pipe.
During hot running-in the following is not allowed: leakage and dripping of oil, coolant and diesel fuel through the gaskets and threaded connections of the manifold; gas emission from under the flanges of the exhaust manifold and through the cylinder head gasket; extraneous knocks and noises in the diesel engine mechanisms.
At the end of the hot running-in of diesel engines, the maximum rotation speed should be no more than 2600 min -1, and the minimum no more than 800 min -1.
Diesel engine faults detected during hot running-in should be eliminated.
The diesel engine should be subjected to repeated running-in and full testing when replacing at least one of the following parts: crankshaft, piston, cylinder liner, piston rings.
When replacing a set of main or connecting rod bearings, the diesel engine is subjected to repeated hot running-in under load.
Acceptance inspection
Acceptance inspection includes acceptance tests, technical and organoleptic control.
During acceptance tests, the nominal power of the diesel engine, specific fuel consumption, maximum and minimum speed, oil pressure at nominal speed are determined and their compliance with the relevant technical requirements is assessed.
Tests must be carried out on summer diesel fuel.
The equipment and control and measuring devices of the running-in and brake stands must ensure the accuracy of measuring the controlled parameters in accordance with GOST 18509-80.
Measuring the controlled parameters must be carried out under steady-state conditions of a warmed-up diesel engine. The temperature of the oil and coolant must be 80-90°C.
Table. Diesel hot running modes
Rotation speed (min) - Load according to the readings of the bench weighing mechanism (PH) - Duration (min):
- 1600 - 50 - 10;
- 1800 - 120 - 5;
- 2000 - 30 - 5;
- 2200 - 320 - 10
The fuel temperature at the inlet to the fuel pump should be 18-50 ° C.
Diesel loading when determining the nominal power and hourly fuel consumption is carried out by increasing the load from idle to maximum with the regulator lever position providing maximum fuel supply.
Main diesel engine performance during acceptance tests:
- - power at rated speed, kW not less than -77;
- - speed, min -1:
- - rated - 2400+
- - at idle: maximum, not more than - 2600; minimum stable, not more than - 800; oil pressure in the main oil line at rated power, MPa - 0.25-0.35; specific fuel consumption, g/kW h, no more than:
- - at rated power - 248;
- - minimum - 221.
The maximum speed should be determined when the diesel engine is running without load by smoothly increasing the speed from the rated to the maximum values.
The minimum stable idle speed should be determined by successively reducing the fuel supply until the speed fluctuations appear that make up ±5% of the measured value.
The duration of diesel engine operation at rated power should not exceed 5 minutes, after which it is necessary to unload the diesel engine and let it run at low power for at least 5 minutes.
Then it is allowed to continue testing the diesel engine at full fuel supply for the next 5 minutes.
The crankshaft speed load and hourly fuel consumption should be measured at the steady-state operating mode of the diesel engine no earlier than 1-2 minutes after entering the mode.
Number of measurements - at least three with an interval between measurements of 1-1.5 minutes.
The rated power of the diesel engine and specific fuel consumption under standard atmospheric conditions according to GOST 18509-80: ambient air temperature +20°C, barometric pressure - 1013 hPa or 760 mm Hg, fuel temperature at the inlet to the fuel pump 20°C must correspond to the data given above.
Checking the start of diesel engines
Check the operation of the pre-heating system by turning on the electric torch heater. After 15-20 seconds, the spiral of the control element should glow bright red.
Perform 2-3 test starts of the diesel engine. To do this, turn on the starter and rotate the diesel crankshaft.
The duration of continuous operation of the starter should not exceed 10 sec. The intervals between starter activations should be at least 1.5 min.
If the diesel does not start to operate stably on the third attempt, it is necessary to identify and eliminate the malfunction.
The test results must be entered into the diesel passport and the test log, which is kept at the repair facility until the expiration of the diesel warranty period.
If the diesel test conditions differ from the standard ones, then the measured power and specific fuel consumption must be bring to standard conditions using nomograms or formulas according to GOST 18509-80.
A diesel engine is considered to have failed the test and is subject to repeated repair if the power and specific fuel consumption (taking into account corrections for standard test conditions), as well as the rotation speed and oil pressure, at least for one parameter, do not meet the requirements and main indicators.
Upon completion of the diesel engine tests, the coolant from the cooling system and the oil from the diesel engine sump must be drained.
During organoleptic control, depending on the readiness of the diesel engine for operation, it is necessary to check the parts and assemblies for visible damage, points and joints, cuff seals, the absence of leaks, the presence of protective coatings, seals on the fuel equipment; check the quality of assembly without disassembling the diesel engine, the quality of paint coatings, completeness, filling of filling tanks.
Each diesel engine is subject to organoleptic testing after acceptance tests, as well as before and after painting.