Motors 740.30-260, manufactured in version "T" in accordance with GOST 15150-69, are designed for operation at ambient temperatures from minus 10 to plus 45 ° C, relative air humidity up to 80% at a temperature of 27 ° C and in areas located at an altitude of up to 3000 m above sea level with a decrease in power, economic and other indicators up to 20%, with overcoming passes up to 4500 m.
General view, longitudinal and transverse sections of the engine 740.30-260 are shown in Figures 1-5
In terms of their environmental performance, 740.30-260 engines comply with the requirements of UNECE regulations at EVRO-2 level.
All the necessary recommendations of the manufacturer on the adjustment of the engine and its systems, the main malfunctions, methods for their detection and elimination are given.
Information is given on chemmotology and standard products used in the design.
The 740.30-260 engine is a four-stroke, compression-ignition, liquid-cooled, eight-cylinder, V-shaped, turbocharged, air-to-air aftercooler (CAC).
In terms of emissions of harmful substances with exhaust gases, the 740.30-260 engine complies with the requirements of UNECE Regulation No. 49-02 B (EURO-2).
The base part of the engine is the cylinder block, on which the units and parts of the engine are installed and fixed.
Wet-type cylinder liners are installed in the bore of the semi-blocks.
The top of the cylinder liners are covered with heads, separate for each cylinder.
The bottom of the cylinder block is closed with a stamped oil sump.
The camshaft is located in the cylinder block on five plain bearings.
The crankshaft is installed at the bottom of the block.
The engine cooling system is liquid, closed type, designed for the use of low-freezing coolant
Technical characteristics of the engine 740.30-260
Parameter name - Value
Engine type - Four-stroke, compression ignition
Cylinder arrangement - V-shaped, 90° camber
Cylinder firing order - 1-5-4-2-6-3-7-8
The direction of rotation of the crankshaft is right-handed (counterclockwise as viewed from the flywheel side)
Cylinder diameter and piston stroke, mm: 120x120
Displacement, l: 10.85
Rated power, kW (hp): 191 (260)
Maximum torque, N m (kgf m): 1079(110)
Setting fuel injection advance angle, deg: 9+1
Crankshaft speed, min-1:
- - nominal 2200±50
- - at maximum torque 1200-1600
- - minimum 600±20
- - maximum 2530-80
Number of valves in the cylinder head - 2 (inlet and outlet)
Clearances on a cold engine, between rocker arms and valve stems:
- - inlet - 0.25...0.30 mm;
- - graduation - 0.35...0.40 mm.
Oil pressure in a warm engine at crankshaft speed, kPa (kgf/cm2):
- - nominal 392...539 (4...5.5)
- - minimum idle speed, not less than 98 (1)
Nozzle, type - 273
Models 273.1112010-21 (273-21)
Atomizer manufactured by YAZDA, model 273.1112110-21 or 273.1112010-51 (273-51)
Atomizer manufactured by f. BOSCH DLLA 148 SV3 142 323
Pressure of the beginning of the nozzle needle lift, MPa (kgf/cm2): 23.73...24.90 (242...254)
Model 3 high pressure fuel pump 37-20
Injection pump (bus equipment) model 337-71
The pressurization system is a gas turbine with two turbochargers and an air-to-air ONV.
Generator model G-273V or 6582.3701 (in accordance with the design documentation) - three-phase synchronous, alternating current, with built-in rectifier unit
- - rated current, A; 28
- - rated rectified voltage, V; 28
- - rated power, kW. 0.8
Mod generator. 6582.3701:
- - rated current, A; 75
- - rated rectified voltage, V: 28
- - rated power, kW. - 2.0
Starter 5662.3708 DC, series excitation, with electromagnetic drive
Rated power, kW 8.2
Possible malfunctions and solutions
- Cause of malfunction
Engine won't start
- Lack of fuel in the tank
Fill the fuel tank, bleed the fuel supply system.
- The presence of air in the fuel supply system
Fix leaks, bleed the system.
- Violation of the adjustment of the fuel injection advance angle
- Freezing of water that has fallen into the fuel pipes or on the grid of the fuel tank intake
Carefully heat the fuel filters, pipes and tank with a rag soaked in hot water or steam, do not use an open flame for heating
The engine does not develop the necessary power, it is unstable, there is smoke during its operation
- Clogged air cleaner or air intake hood
Maintain the air cleaner or clean the hood screen
- Insufficient fuel supply
Replace the elements of the fine fuel filter, wash the coarse filter, tighten the connections in the fuel pipes.
- Violation of the adjustment of the fuel injection advance angle
- Clogging of the nozzle (coking of the sprayer holes, freezing of the needle) or violation of its adjustment.
Rinse the nozzle, replace the nozzle if necessary, check and adjust if necessary.
- Violation of the adjustment of the regulator control lever drive (the control lever does not reach the bolt for limiting the maximum crankshaft speed).
Check and adjust the governor drive.
- Breakage of the injection pump pusher spring.
Replace the spring and adjust the pump on the stand.
- The ingress of dirt between the seat and the valve of the fuel priming pump or the breakage of the spring.
Rinse the valve or replace the spring, test the pump on the stand.
- Violation of the tightness of the injection valves of the high-pressure fuel pump or breakage of the spring.
Repair valve leaks in workshop or replace spring.
- Jamming of the plunger of the injection pump section
Replace the plunger pair and adjust the pump.
- Violation of the adjustment of thermal gaps in the gas distribution mechanism.
- Depressurization of the membrane cavity or damage to the membrane of the charge air pressure corrector.
Restore the tightness of the membrane cavity or replace the damaged membrane.
- Stopping the oil supply to the charge air pressure corrector.
Restore the oil supply to the corrector.
- Loose fastening or breakage of the high pressure tube.
Tighten the fastening nut or replace the tube.
- Poor compression due to malfunctions of the piston group or loose fit of the gas distribution valves to the seats.
Check the condition of the pistons and piston rings, grind the valves.
- Fuel thickening (during the cold period).
Replace the elements of the fine fuel filter, replace the fuel with the appropriate one for the season, bleed the fuel supply system.
Low charge air pressure:
- air leakage through the intake manifold connections with cylinder heads, nozzles, turbochargers and compressor;
Tighten connections, if necessary, replace gaskets and connecting hoses.
- gas breakthrough in the connections of the exhaust manifold and the turbine housing;
Tighten connections, replace gaskets if necessary.
- turbocharger rotor sticking;
- pollution of the exhaust tract, flow parts of the compressor and turbine.
Clean the pipelines, remove the turbocharger, and remove deposits from the flow parts.
Extraneous noise in the turbocharger
- Rotor hitting against body parts
Tighten the bolts securing the turbine and compressor housings.
Check that the rotor is not touched at its extreme positions.
If the rotor is rubbing, replace the turbocharger.
If the noise persists, remove the turbocharger for service vanity.
High frequency noise (whistling)
- The tightness of the intake and exhaust ducts of the engine is broken
Tighten the bolts and nuts securing the system parts, if necessary, replace the gaskets.
Increased oil consumption
- Prolonged engine idling.
Don't idle the engine unnecessarily.
- Oil leakage through the connections in the turbocharger lubrication system.
Tighten connections, if necessary, replace seals and rubber sleeves.
- Deterioration of the valve-sleeve interface in the cylinder head, aging of the rubber cuff of the valve.
Check and replace worn parts.
- Clogged air cleaner or air intake hood.
Maintain the air cleaner and clean the hood mesh.
Reducing the oil pressure in the lubrication system
- Low oil level in the oil sump.
Check and, if necessary, add oil to the "B" mark.
- Malfunction of pressure control devices
Make sure the devices are working.
- Use of oil of the wrong viscosity
Change the oil with the corresponding chemotological map.
- Dirty oil filter elements
Replace filter elements.
- Violation of adjustment or jamming of the safety valve or valve of the lubrication system
Check valves and eliminate jamming, adjust or replace faulty parts if necessary.
- Clogged oil pump intake
Rinse the intake.
- Coolant getting into oil
Check the tightness of the water chamber, the seal of the cylinder liners, the tightness of the water-oil heat exchanger, replace the defective parts.
- Oil leaks at the joints and oil lines of the lubrication system
Check the condition of technological plugs, plugs, tightness of fasteners at the joints, the condition of sealing rings and gaskets.
- Violation of the oil pump
Remove the pump and check its operation on a special stand.
- Inadmissible increase in clearance in the bearings of the crankshaft and camshaft
Repair the engine.
Emergency oil temperature indicator lights up
- Malfunction of emergency oil temperature sensor
Make sure the sensor is working, replace if necessary.
- Sticking of the thermal valve for turning on the heat exchanger, malfunction of the thermal force sensor
Check the operation of the heat exchanger thermal valve, if necessary, remove jamming or replace the sensor.
- Clogged pipes or dirty cooling plates
Check the oil/water heat exchanger for clogged tubes and dirty cooling plates, flush or replace the heat exchanger if necessary.
Increasing oil pressure in the lubrication system
- High oil viscosity.
Change the oil to the appropriate chemotological card.
- Violation of the tightness of the control signal line connecting the main oil line with the pump or its clogging
Check the oil supply pipe to the pump, the tightening of the fastening bolts, the presence of a hole in the cover.
- Jamming or misadjustment of the lubrication system valve.
Check the valve and remove the jam, if necessary, replace the faulty parts.
- Early injection of fuel into the cylinders.
Adjust fuel injection advance angle.
- Increased thermal gaps in the gas distribution mechanism
- Wedging of the valves of the gas distribution mechanism in the bushings (the piston touches the valve)
Disassemble and clean the valve mechanism. Replace the valve if necessary.
- Increased cyclic fuel supply (rack lock disengaged)
Replace injection pump rail
A dull tone of crankshaft noise. The frequency increases with increasing crankshaft speed
- An unacceptable increase in the gap between the journals and the main bearing shells as a result of the use of oil that does not match
specified in this manual, or reduce pressure and oil supply.
Grind the necks to the size of the repair size and replace the liners, change the oil and check the operation of the oil pump.
- Inadmissible increase in the gap between the thrust half rings and the crankshaft.
Replace thrust half rings with new ones of greater thickness.
- Loosening the bolts of the flywheel to the crankshaft.
Find the cause and tighten the bolts.
The sound of the connecting rod bearings is louder than the sound of the main bearings. Heard when the engine is idling and intensifies with increased crankshaft speed
- An unacceptable increase in the gap between the journals and the connecting rod bearing shells as a result of the use of oil that does not match
indicated, or reduce pressure and supply oil.
Grind the necks to the repair size and replace the liners, change the oil and check the operation of the oil pump.
Piston knock is muffled, caused by the beating of the pistons against the cylinders. Audible at low crankshaft speed and under load
- Inadmissible increase in the gap between pistons and cylinders.
Replace pistons and, if necessary, cylinder liners.
- Strong wear of the ends of the piston rings and the corresponding grooves on the piston.
Replace piston rings and, if required, pistons.
The sound of piston pins, double, metallic, sharp is caused by a large gap. Better heard when the engine is idling
- Inadmissible increase in the gap between the pin and the bushing of the upper head of the connecting rod.
Replace the pin and, if necessary, the connecting rod.
Increased fluid temperature in the cooling system*
- Weak tension or breakage of the water pump drive belts.
Tighten or replace belts.
- Faulty thermostats
- Pollution of the radiator core.
Clean the radiator core from dirt.
Increased coolant consumption
- Radiator damage
Repair damage or replace heatsink
- Liquid leakage through the mechanical seal of the water pump.
Replace the mechanical seal.
- The ingress of coolant into the lubrication system through the rubber sealing rings of the cylinder liners or through the rubber gaskets of the cylinder heads.
Replace cylinder liner O-rings or rubber gaskets.
* Before looking for the cause of a malfunction in the lubrication and cooling system, you need to make sure that the oil pressure and temperature indicators are working.
ELECTRIC TORCH DEVICE (EFV)
EFU spark plug is faulty, 30A fusible link is on
- Closing the spiral of a thermal switch or electrical wires
If the candles are in good condition, disconnect the wire from the thermal relay connecting it to the power button of the EFU.
The absence of a circuit when the EFU is turned on again indicates that the thermal relay coil is closed. In this case, the thermostat should be replaced.
If the spiral of the thermal relay is intact (determined by touch) and when the wires are disconnected from the candles, a short circuit occurs, then this indicates a short circuit in the electrical wires. Remove the short.
- Closing the candle to ground
Disconnect the wire from the output of the left candle, eliminating the contact of the tip with the ground, and turn on the EFU again. When closing, disconnect the wire from the output of the right candle.
Absence of closure indicates a closure of the right candle. Replace a failed spark plug.
After the short circuit is eliminated, it is recommended to check the condition of the insulation of the electrical wires, the operability of the thermal relay and the EFU switch-on relay, and if the short circuit occurred when the engine was started, the operability of the shunt relay
EFU does not work, voltage is not supplied to the EFU
- Thermal relay coil burnout
Turn on the EFU and check the voltage at the thermal relay outputs. The absence of voltage at the output from the side of the plug connection, while there is voltage at the other output, indicates a burnout of the spiral. Replace thermostat.
- Burnout of candles or lack of contact in the circuit
Turn on the EFU and check if there is voltage at the terminals of each EFU product, starting with the torch candles. The presence of voltage at the output of the right candle indicates the burnout of the candles. Replace spark plugs or restore contact.
- Burnout of one of the candles
Turn on the EFU for 10-15 seconds, then replace the cold plug.
No torch candles
- Lack of fuel supply to the candle
Loosen the fuel supply fitting on the spark plug. Turn on the EFU and, after the signaling device lights up (opening the electromagnetic valve), turn
Using a starter crankshaft. If the fuel does not seep through the loose fitting threaded connection when the valve is open, repair the malfunction in the fuel supply system.
- Fuel not passing through the spark plug
Unscrew the spark plug from the manifold. Rinse and blow out the jet, fuel filter and fuel supply cavities with compressed air. Check for the presence of a torch flame, for which:
- - connect a fuel pipe and electrical wires to the spark plug;
- - ensure a reliable connection of the candle body with the mass and make sure that the lead is isolated from the mass;
- - turn on the EFU and turn the crankshaft using the starter.
If there is no flame, replace the defective candle.
Indicator lamp charge circuit gat rated engine speed
- Loosening the tension of the alternator drive belts
Adjust belt tension
- Contamination of slip rings
Wipe the rings with a cotton cloth moistened with clean gasoline. If the contamination persists, clean with glass sandpaper and wipe again with a napkin
- Wear or sticking of brushes in brush holders
Check the height of the brushes, their free movement in the channels of the brush holder and the force of the springs; if necessary, replace the brush holder or brushes
- Breakdown of the rectifier unit
- Short circuit of the stator winding
Replace stator assembly
- Violation in the excitation circuit
Check the excitation circuit
- Wear of bearing parts or their destruction
- Generator fan deformation
Fix bent spots
- Excessive belt tension
Adjust belt tension
Excessively fast generator brush wear
- Contamination of slip rings
Wipe the rings with a cotton cloth moistened with clean gasoline. If necessary, clean with glass sandpaper and wipe again with a napkin
- Radial runout of slip rings
Check the radial runout of the rings. If required, grind slip rings
Excessive charging current
- Short circuit in the brush assembly of the generator or in the circuit between the generator and the regulator
- Faulty voltage regulator
- Malfunction of the relay for turning off the excitation winding of the generator
Increased noise levelduring generator operation
- Pulley loosening
Tighten the nut
- Lack of contact between brushes and commutator
Wipe the collector with a clean cloth soaked in gasoline, or clean it. Clean the brushes or replace them with new ones. Check Status
brush springs and replace them if they are defective. Check if the brushes in the brush holders are jamming
Starter does not work
- Short circuit or open circuit of the retracting winding of the traction relay
- Breakage or lack of contact in the power supply circuit
Find the damage and restore contact
- Hanging brushes
Remove the brush holder, remove the brushes and remove brush dust
- Starter relay failure (738.3747-20)
- Open circuit inside the starter
Check and fix starter defects or replace starter
The engine crankshaft does not turn with the starter (the traction relay is activated)
- Discharging batteries
- Violation of the AB charging circuit
- Faulty voltage regulator
- Oiling or contamination of the brush-collector assembly
Clean the collector and brushes from oil, dirt, copper-graphite dust
- Poor contact of the starter housing with the mass of the power plant
Ensure connection reliability
- Using an oil that doesn't match the season
Change the oil
After starting the engine, the armature continues to rotate
- Malfunction of the traction relay
- Welding starter relay contacts (738.3747-20)
When the starter is turned on, the traction relay does not work (there is no characteristic click)
- Discharging the battery
- Breakage of the retracting winding of the traction relay
- Faulty instrument switch and starter
- Open or short circuit of the starter relay winding (738.3747-20)
Starter armature rotates but does not turn crankshaft
- Breakage of the teeth of the flywheel crown or gear wheel
Replace flywheel ring or drive gear
- Violation of starter adjustment
- Drive failure
When the starter is turned on, repeated clicks of the traction relay are heard and the blows of the gear wheel of the drive against the flywheel rim
- Unreliable contact of the starter traction relay circuit
Check contact connections and troubleshoot
- Malfunction of the holding winding of the traction relay
Replace the traction relay
- Malfunction of the winding or contact connection of the starter relay (738.3747-20).
When the starter is turned on, noise (grinding) of the gear wheel of the drive is heard
- Installation of a starter with a warp
Install the starter correctly
- Incorrect adjustment of the closing moment of the contact traction relay
Adjust the gap between the gear wheel and the thrust washer at the moment the starter is turned on
The drive gear does not systematically engage with the flywheel ringduring normal operation of the relay
- The presence of burrs on the ends of the teeth of the flywheel or drive gear
Filing and deburring the teeth of the flywheel ring or drive gear
- Wear of the ends of the teeth of the flywheel crown or drive gear
Replace flywheel ring or drive gear