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ADJUSTING THE VALVE AND DECOMPRESSION MECHANISMS OF DIESEL A-01, A-01M and A-41

In the valve mechanism, the gap between the end of the valve stem and the rocker arm is adjusted. This gap is necessary for a tight fit of the valve into the seat in the cylinder head and to compensate for the thermal expansion of the parts of the valve drive mechanism during engine operation.

Gap A (see Fig. 14) between the inlet and outlet valve stem and the rocker arm striker is set the same within

0.25-0.30 mm. With a larger gap, they move valve timing, filling and cleaning of cylinders worsens, shock loads and wear of parts of the gas distribution mechanism increase, even a valve stem breakage may occur. With a smaller gap, the valve does not sit tightly in the saddle. As a result, the tightness of the combustion chamber is broken, the engine compression is reduced, it is difficult to start, the engine overheats and does not develop full power.

Incomplete closing of the valves leads to burnout of the working chamfers due to the breakthrough of hot gases.

Checking and adjusting the clearance between the valve stem and the rocker arm

The gap is checked both on a cold and on a hot engine, but not earlier than 15 minutes after it stops. Check in this order:
turn off the fuel supply;

Caps 7 (see Fig. 16) of cylinder heads are cleaned of aching. Unscrew the nuts 13 for fastening the caps, disconnect the lever for turning on the decompression mechanism and remove the caps;

Check the tightening of the nuts for fastening the racks 11 of the axis of the rocker arms and the nuts securing the cylinder head to the block;

Use a screwdriver or wrench to set the decompression mechanism to the on position to facilitate scrolling. crankshaft;

observing the rocker arms of the valves of the first cylinder, slowly rotate the crankshaft clockwise with the handle until both valves (exhaust and then intake) open and close, which corresponds to the initial period of the compression stroke. The set screw is unscrewed from the hole in the flywheel housing and inserted with its uncut part into the same hole until it stops in the flywheel disk;

While pressing the set screw with your hand, continue to turn the crankshaft until the screw enters the recess on the flywheel disk; in this position of the crankshaft, the piston of the first cylinder is in c. m.t. after the compression stroke;

The decompression mechanism is turned off and the gap between the rod and the striker of the rocker arm of the intake and exhaust valves of the first cylinder is checked with a feeler gauge.

If necessary, adjust the gap.

To adjust the gap, you must:

Loosen the locknut 12 (see Fig. 14) of the adjusting screw 1.3 on the valve rocker, holding the adjusting screw with a screwdriver;

Insert a 0.25 mm thick feeler plate into the gap and, turning the adjusting screw with a screwdriver, set the required gap;

While holding the screw with a screwdriver, tighten the locknut and check the clearance by turning the push rod by hand to see if it is binding. With a correctly adjusted gap, a 0.25 mm thick probe should enter with light pressure, a 0.30 mm thick probe with force.

Adjusting the Decompression Mechanism

After adjusting the clearance in the valves of the first cylinder, the decompression mechanism in this cylinder is adjusted in the following order:

Turn on the decompression mechanism, install the roller 8 so that the axis of the adjusting screws 7 is vertical; loosen the adjusting screw locknut; with an unlocked adjusting screw, select the gaps between it and the back of the rocker arm, the valve stem and the rocker arm;

Turn the adjusting screw one turn clockwise, while the valve opens slightly;

The adjusting screw, holding with a screwdriver, is countered with a nut.

After adjusting the decompression mechanism of the first cylinder, screw the set screw with a threaded part into the hole in the flywheel housing.

With further crankshaft rotation clockwise, the valve and decompression mechanisms are respectively adjusted in the next engine in order of operation.

For A-01 engines and its modifications, the crankshaft is rotated through 120 ° (1/3 of a turn), for A-41 engines and its modifications, through 180 ° (1/2 of a turn), which will correspond to the end of the compression stroke in each subsequent cylinder (taking into account the order of operation of the cylinders).

It should be borne in mind that before adjusting the gaps, the intake and exhaust valves must be closed. In this position, they are checked by turning the rods by hand.

After adjusting the valve and decompression mechanisms, the engine is started, if the knock of the valves is heard, the engine is stopped and the gaps are checked again.

At the end of the adjustment, the cylinder head caps are installed in place, observing the correct laying of the gaskets 6 (see Fig. 16). Oil leakage is not allowed in the places where the caps fit on the cylinder heads.

61 62 63 64 65 66 67 68 69 ..

ADJUSTMENT WORKS AND MAINTENANCE OF THE COMPONENT PARTS OF THE DT-75M TRACTOR.

Tractor DT-75M. Adjustment of gaps in gas distribution and decompression mechanisms

Tools, fixtures: socket wrench S = 27, spanners S = 10,12,14,17, torque wrench, screwdriver, pliers, crankshaft crank, set of probes.

Check and adjust clearances on a cold engine or 15 minutes after stopping it:

A) disconnect the decompressor linkage and remove the cylinder head caps;

B) check the tightness of the rocker arm strut fastening nuts, the tightening torque of the cylinder head fastening nuts and, if necessary, tighten them;

C) turn on the decompression mechanism using the key (by the flats of the roller);

D) observing the rocker arms of the valves (Fig. 69) of the fourth cylinder, turn the crankshaft with the handle until the valves in this cylinder overlap (the exhaust valve has not yet closed, and the inlet valve has just begun to open);

E) unscrew the mounting pin (Fig. 70) from the flywheel housing and insert its uncut part into the same hole until it stops in the flywheel;

E) while pressing the mounting pin, slowly turn the crankshaft until the pin enters the hole on the flywheel. In this position of the flywheel, the piston of the first cylinder will be at TDC of the compression stroke;

G) turn off the decompression mechanism;

H) check the gap between the valve stem and the rocker arm of both valves of the first cylinder with a feeler gauge and adjust if necessary. With a properly adjusted gap, a 0.25 mm thick probe should enter with light pressure, a 0.3 mm thick one with force.

To adjust the gap:

Rice. 69. Tractor DT-75M. Engine location

unscrew the locknut of the adjusting screw;

Insert a feeler gauge 0.25 mm thick into the gap;

Screw in or out with a screwdriver the adjusting screw

Until the required clearance is obtained, hold the locknut with a wrench;

Lock the adjusting screw with a locknut, holding it with a screwdriver;

Check the gap with a feeler gauge by turning the push rod by hand to make sure that it is not jamming;

i) adjust the decompression mechanism for this cylinder:

Install the decompressor roller so that the axis of the adjusting screws 9 (Fig. 25) is vertical;

Loosen the locknut of the adjusting screw and turn it in or out until there is a full gap between the valve and the rocker arm (0.25-0.30 mm),

and then screw it in one turn and lock;

J) screw the adjusting pin into the hole of the flywheel housing;

K) sequentially adjust the clearances in each cylinder, as indicated above, in the order of their operation (1-3-4-2).

Rotate the crankshaft 180° in the direction of rotation to adjust the valve clearances and decompression mechanism of the next cylinder.

After adjusting the clearances, start the engine and listen to its operation. If valve knocking occurs, stop the engine and check the clearances again. When re-checking, the gaps should be within 0.2-0.35 mm;

M) install the cylinder head caps, following the correct installation gaskets.

Tractor DT-75M. Lubrication valve adjustment

Tools, fixtures: stand for checking lubrication system units, wrenches S = 12,14,17,22,27,32,36, socket wrench S = 12, hammer, chisel, pliers, screwdriver.

When the oil pressure in the main oil line it is allowed for maintenance No. 3 to re-adjust

Valves of the lubrication system. Adjust the valves on the stand for the opening pressure: drain valve - 4.5-5.0 kgf / cm2; pressure reducing valve discharge section of the oil pump - 9.0-9.5 kgf / cm2; safety valve of the radiator section of the oil pump - 2.5-3.2 kgf / cm2.

Adjust the drain valve installed in the centrifuge body with an adjusting screw, the pressure reducing and safety valves of the oil pump - with shims. After adjusting the valves, check the performance of the oil pump on the stand.

Starting engines P-23M, P-23 and P-46. For a warm engine, the gap between the stem of any valve and the head of the pusher adjusting bolt should be 0.2-0.25 mm.

To adjust, you need remove manhole covers valve mechanism, unscrew the candles, then, turning the crankshaft with the handle, at the compression stroke of the first cylinder, align the flywheel mark of the TDC-1 starting engine with the risk on the hatch wall; after that, turning the adjusting screw of the pusher, with the lock nut loosened, set the desired gap and tighten the lock nut, checking the gap.

Engines AM-01, AM-03 and AM-41. In a cold engine, the gap between the rocker arm and the valve stem should be 0.25 mm at the intake valve and 0.30 mm at the exhaust valve.

To adjust, it is necessary to turn on the decompression mechanism and, by matching the mounting pin with the flywheel hole, set the piston of the first cylinder to TDC on the compression stroke; turn off the decompression mechanism and, if necessary, adjust the mechanism of the SMD-14 engine.

Engines D-50 and D-50L. The valves are checked and adjusted after 240 hours. The temperature of the cooling water must not be lower than 75 C. The gap between the rocker arm and the valve stem must be 0.25 + 0.05 mm for all valves.

When checking on a warm engine, gaps without adjustment of 0.25 $ $ mm are permissible.

Engines D-54A and D-75. The gap between the valve stem and the rocker arm for a cold engine should be 0.30 mm for the intake valve and 0.35 mm for the exhaust valve, and on a warm engine, 0.25 and 0.30 mm, respectively.

To adjust the gap, it is necessary to check the condition of fastening of the levers of the rollers and the rods of the decompression mechanism; remove the valve cover caps; check the reliability of the fastening of the racks of the valve rocker arms and the cylinder head to the block; set the lever of the decompression mechanism to the “Warm-up I” position and, turning the crankshaft with the handle, ensure that the mounting pin coincides with the flywheel hole at the compression stroke in the first cylinder; then set the decompression mechanism lever to the “Run” position and, if necessary, adjust the clearances of the intake and exhaust valves of the first cylinder.

YaMZ-238NB engine. On a cold engine, the clearance for all valves should be 0.25-0.30 mm. To adjust the valve clearance, it is necessary to remove the cylinder head covers - and check the tightening torque of the rocker roller bolts (12-15 kgm); then, turning the crankshaft with a wrench on the pulley mounting bolt, set the piston of the first cylinder to the position of the end of the compression stroke.

V-30 engine. When adjusting the gap between the valve plates and the backs of the cams, you should first adjust the excess of the valve plate plane above the upper plane of the block head. This value is the same for all valves and is within 42 ± 0.1 mm.

The excess is adjusted by screwing or unscrewing the poppet into the valve opening.

Engines KDM-100, 6KDM-50, D-108, D-130 and D-180. The gap between the rocker striker and the valve stem (for KDM-100 and 6 K DM-50 engines between the rocker striker and guide cup) for a warm engine for all valves should be 0.3 mm. Clearances should be checked after 240 hours. engine operation.

Engines D-16 and D-37M. On a cold D-16 engine with cast-iron cylinder heads, the gap between the rocker arm and the valve stem should be 0.25 mm at the intake valve, and 0.30 MMi at the exhaust valve. On a cold D-37M engine and with aluminum at the intake and exhaust valves, it should be equal to 0.08-0.10 mm.

Domestic construction and agricultural machinery, special vehicles are equipped with various power units. One of their representatives is the A 41 diesel engine, manufactured by the Altai Motor Plant, located in Barnaul.

Specifications

A 41 is a series of four-cylinder naturally aspirated diesel engines. Their main purpose is operation in construction equipment and agricultural machines. A 41 is a high-quality, unpretentious, durable unit, easy to operate and has good maintainability, and this characteristic of A 41 engines allowed it to gain consumer recognition.

A41 taken from the DT-75 tractor:

Technical characteristics of the A 41 engine in the stock version:

• Engine weight A 41: 930 kg.
• Motor dimensions: length 1425 mm, width 827 mm.
• Execution of the block of cylinders: pig-iron BC.
• Fuel supply: diesel direct injection method.
• Cylinder operation algorithm: 1 - 3 - 4 - 2, counting is from the motor fan.
• Volume: 7.43 liters.
• Developed power: up to 90 Horse power.
• The number of revolutions according to the passport: 1750 rpm. in a minute.
• Cylinders: 4.
• Cylinder arrangement: mounted vertically.
• Piston stroke length: 140 mm.
• Individual cylinder diameter: 130 mm.
• Standard compression ratio A41: 16.
• Developed: 412 Nm at 1300 rpm.
• Fuel consumption: min. 1.62 kWh.
• Cooling system diesel engine A 41: liquid.
• Oil used: DS-11 in summer, DS-8 in winter.
• Motor generator: assembly direct current 7=G304, 214A1.
• Number of timing valves: 2
• Hydraulic pumps: 2 gear pumps, crankshaft driven by gear type transmission.
• Declared engine life: 12 thousand engine hours per latest models engine.

Where is the AMZ A-41 engine installed

This motor is equipped with excavators, graders, power plants and pumping units, other equipment in agreement with the manufacturer. Of the tractors, it is used on the T-4, DT-75M, T-4A tractors.

Overview and Features - A-41 Engine

The 90-horsepower engine has a solid cylinder capacity of 7.43 liters, which allows the base model A 41 to produce such power at relatively low speeds, about 1750. Following the trends in engine building, the developers introduced a block into the A 41 electronic system direct injection: fuel supply is fully electronically controlled.

An important feature of the A 41 motor is a two-valve gas distribution mechanism. Engineers used it to give the engine the highest possible efficiency, output and efficiency.

To make the unit more reliable, the A 41 uses high-strength cast iron sleeves, the surface of which is processed by the method of vertex honing. This increases the life of the motor, coupled with a well-thought-out cooling system (however, the weight also grows). As such, an external oil-liquid heat exchanger is used, which cools the engine equally well both at idle and at maximum loads. By maintaining a stable and comfortable operating temperature engine reliability has been further improved.

An interesting feature of the engine: when the engine is running, the valves are able to turn under the influence of their own springs and the vibrations accompanying the engine's work cycles. This can be attributed to the advantages of the design, since the valve stem wears out more evenly (although the chamfer of the valve disc wears out too).

The engine camshaft must withstand heavy loads, so it is hardened with high-frequency currents. The camshaft has 7 necks and 12 cams that ensure the operation of the mechanism. The assembly is driven from the crankshaft by means of a gear transmission.

The developers took care of environmental friendliness power unit: the engine that left the AMZ workshops complies with the domestic standard R 41.96-2005 for the absence of violations in the emission of pollutants and harmful substances.

Motor modifications

The engine is available in various variations designed to work with certain special equipment.

Main Models:

The basic engine model and modifications are installed on tractors and other equipment, in agreement with the manufacturer. In total, there are more than 11 variations of the motor, differing mainly in additional equipment. You can put:

• two hydraulic pumps;
• upgraded clutch block clutch;
• muffler;
• pneumatic compressor;
• starting electric torch heater;
• enlarged engine oil cooling system heat exchanger, etc.

Modifications of the A-41SI1, 02 and 03 engine differ from each other in the arrangement of cylinders: the latter received an in-line layout, due to which the rated power developed by the engine increased to 100 forces, and the torque margin - up to 20%, compared with counterparts. On the popular tractors of the DT-75 series, according to the catalog of the plant, motors A 41I, SI, S are installed.

Since 2001, during assembly, engines have been assembled with their own head for individual cylinder groups, which has improved the reliability of the gas joint and reduced engine oil consumption “for waste”. In 2003, a modification was created with an electric starter, thanks to which the motor resource increased. And in 2012, the crankcase block of the A 41 engine was replaced with licensed German crankcases, which made the engine even more reliable.

crankcase:

The A-41 has a related A-01 engine, also designed to work on special equipment. Unlike the A-41, the second engine has 6 cylinders.

Maintenance

As already mentioned, A 41 and its modifications are unpretentious to working conditions and service. Qualified Technician to get the job done current maintenance on one's own.

In fact, for a long and trouble-free operation of the motor, it is necessary, basically, to monitor the oil temperature and pressure in the oil line, not allowing the lubricant level to fall below a critical level, and flush. Oil change is carried out regularly, every 240 hours of engine operation.

An important regular operation is clutch adjustment, since with gradual wear of the disc linings, the retraction gaps of the middle disc and the free play of the clutch increase. Schematic clutch device using the example of one in the DT-75 tractor:

This is a double disc clutch of dry design, permanently closed type. Adjustment of the clutch DT 75 with the engine A 41 should be carried out, if necessary, according to the result of the check, approximately every 240 hours.

Over time, it may also be necessary to adjust the valves of the A 41 engine. A gap of 0.25 ... 0.3 mm is allowed for both valves of this engine.

The motor should also be serviced every shift, at the end of the shift or before it begins. The interval of the current service is about 10 hours. The set of manipulations includes:

• cleaning the engine from dirt, accumulated dust;
• checking the fasteners and the state of the tightness of the joints;
• absence control extraneous noise;
• check for fuel, water and engine oil leaks.
• The engine cooling system should also be serviced regularly. The set of service operations includes:
• descaling the cooling unit, flushing the system;
• leak testing and sealing weaknesses radiator, if necessary.

Typical malfunctions

The motor has some characteristic problems.

• Overheat.

Water is mainly used as a coolant in the engine cooling system, which leaves calcium deposits on the radiator cells and sediment in the tubes and cavities of the system. Therefore, you should regularly check the condition of the radiator and flush it, especially if the engine is expected to operate at high loads. Sometimes, in advanced cases, it is necessary to change a failed pump or an A 41 engine thermostat that has stopped working.

• Abnormally high consumption of engine oil for waste.

The reason for this is the leaky valve lid, its own for a separate cylinder group. Just for fixing this shortcoming the new models use German-made crankcase blocks.

• loss of engine power, strong vibrations when the motor is running.

The likely cause is a defect in the crankshaft assembly or pistons. You should also check the balancing bearings, they tend to break down with the subsequent mandatory replacement of those.

• Poor engine start, interruptions in operation.

The reasons for this may be a malfunction of the injection system or clogged with dirt fuel filter. You should diagnose the fuel system, clean or replace the filter, and if this operation has no effect, open the engine and check the internal components.

tuning

In some situations, the power of the A41 engine may not be enough. As in "civilian" engines, there are some technical tricks here that allow you to shoot from power plant increased power.

• Turbine installation from 440 series motors.

This is a complex operation, which also requires the installation of connecting rods and a lubrication system that correspond to the new characteristics of the engine. Subject to these requirements, the motor becomes capable of delivering up to 145 forces, while maintaining the standard motor resource.

• Flashing.

Some increase can be achieved by purely software manipulations, by reprogramming electronic device engine control.

Important: at the same time, it is highly desirable to install more efficient nozzles, since regular ones may not be able to cope with the load.

In this way, 5-10 more horsepower is added to the characteristics of the A 41 engine than in the stock version.

The diesel four-cylinder engine A 41 is manufactured by the Altai Motor Plant and is intended for installation on heavy construction equipment and agricultural vehicles.

Specifications

OPTIONS	MEANING
Engine weight, kg	930
Dimensions (length/width), mm	1425/827
Block material	cast iron
Supply system	direct injection
Engine operation order (reading from the fan side)	1 - 3 - 4 - 2
Working volume of cylinders, l	7.43
Power, l. with.	90
Nominal number of revolutions, rpm.	1750
Number of cylinders	4
Cylinder arrangement	vertical
Piston stroke, mm	140
Cylinder diameter, mm	130
Compression ratio	16
Maximum torque at 1200 - 1300 rpm, Nm	412
Fuel	diesel
Minimum specific fuel consumption, kWh	1.62
Cooling system	Liquid, with forced circulation of coolant
Butter	Summer diesel oil DS-11 (M12V) or M10V; in winter - DS-8 (M8V).
Generator	DC 214A1 or G304.
hydraulic pumps	2 gear pumps NSh10DL and NSh46UL; gear drive from the crankshaft.

The engine is installed on tractors DT-75M, T-4A, T-4, excavators, rollers, motor graders, pumping units, power plants.

Description

The working volume of this four-cylinder diesel engine A 41 is 7.43 liters, which allows you to provide power of 90 horsepower at 1750 rpm. The A 41 engine has a direct injection system, which, on the latest modifications, is fully electronically controlled.

A design feature of this power unit is a two-valve gas distribution mechanism, which allows for maximum efficiency and return. To increase the reliability of the design in the A 41 diesel engine, special sleeves were used, made of cast iron with surface treatment using vertex honing technology.

The cooling system used can significantly reduce the operating temperature, which has a positive effect on the reliability of this power unit. To cool the oil, an external liquid-oil heat exchanger is used, which ensures the ability of the power unit to operate at maximum loads and in difficult conditions operation.

Modifications

Over the years this engine has been on the assembly line, it has undergone minor changes that have significantly simplified the maintenance of equipment, improved its reliability indicators, reduced fuel consumption and increased power indicators.

So, for example, the A-41SI-03 modification has an in-line arrangement of cylinders, which made it possible to increase the rated power from 90 to 100 horsepower. This power unit has a torque reserve factor of 20%, while for the modification A-41SI-1 and A-41SI-02 this figure is 15%.

Since 2001, in the manufacture of these power units, individual block heads have been used for each of the cylinder groups, which in turn has increased the reliability of the sealing of the gas joint and reduced oil consumption during waste.

The engine, during its time on the assembly line, has been improved, receiving various electronic blocks management. In 2003, this power unit began to be equipped with an electric starter, which increased its motor resource. In 2012, under license for diesel engine And 41 began to install German crankcase blocks, which increased the reliability of the motor.

AT total 11 different modifications were produced, most of which are the base motor with an additional attachments. So, for example, it is possible to install two hydraulic pumps, a belt pneumatic compressor, an additional generator, an enlarged liquid-oil heat exchanger designed for oil cooling, an upgraded clutch and a number of other elements.

Maintenance

Service maintenance of this power unit is not particularly difficult, which allows you to perform such work yourself.

• In fact, when operating equipment with this type of engine, it is only necessary to constantly monitor the pressure and temperature of the oil, without fail to check the current level of lubrication, and flush oil filter and timely change the oil every 240 hours.
• Every shift maintenance is carried out daily, at the beginning or end of the shift, every 8-10 moto-hours of work. At the same time, the motor is cleaned of dust and dirt, the fasteners and the tightness of the connection are checked, whether there are any extraneous noises, adding fuel (if there is any leakage), oil and water.

On a regular basis, the engine cooling system of modification A 41 is serviced. It is mandatory to flush the system with descaling, and in the presence of a leak, additional sealing of the radiator is performed.

Faults

MALFUNCTION	CAUSE
The engine overheats, which makes it impossible to operate the equipment.	The cooling system of this power unit uses mainly water, which can lead to precipitation or the appearance of calcium deposits on the radiator cells. That is why it is necessary, when the operating temperature is increased, to inspect the condition of the radiators, rinse them, removing the corresponding scale. In some cases, you have to replace the thermostat or replace a broken pump.
There is an increased loss of oil.	The reason for this may be a valve cover that has lost its tightness, which is installed separately for each group of cylinders. A similar problem was solved in the latest modifications of this motor, where German crankcase blocks were used.
The A 41 engine has lost most of its power and runs with noticeable vibration.	It is necessary to open the power units, check the condition of the pistons and crankshaft. Quite often, balancing bearings fail, which require appropriate replacement.
There are interruptions in the operation of the engine and problems with starting are noted.	The cause of such a breakdown may be a clogged fuel filter or problems with the injection system. You need to check the condition first. fuel system, then open the motor.

tuning

1. Tuning this power unit is to install a turbine from the 440 series engines. Such a motor, subject to the replacement of connecting rods and the lubrication system, is capable of delivering about 145 horsepower without any reduction in engine life.
2. It is possible to increase the power of the power unit by reprogramming the control unit and replacing the injection system. Having carried out such a modernization of the A 41 engine, you can get an additional 5-10 horsepower.