Contents
Preface
Fig. I. Overall and mounting dimensions of model YC4108D diesel engine
Fig. II. Overall and mounting dimensions of model YC4108ZD diesel engine
Fig. III. Load characteristic curve of model YC4108D diesel engine
Fig. IV. Load characteristic curve of model YC4108ZD diesel engine
1 Engine specifications and accessories 1
1.1 Engine specifications 1
1.2 Technical data of adjustment and control for engine 1
1.3 Tightening torques of the connecting screw thread 2
1.4 Main parts fit clearances 2
1.5 Specifications of main parts and accessories 4
2 Main installing requirements 5
2.1 Installation of the crankshaft 5
2.2 Installations of the piston and the connecting rod 5
2.3 Installation of the camshaft 6
2.4 Installation of the valves and valve guides 6
2.5 Installation of the injectors 6
2.6 Installation of the cylinder head 7
2.7 Installation of the gear train 7
3 Engine adjustment 7
3.1 Fuel supply advance angle adjustment 7
3.2 Adjustment of the valve clearance 8
3.3 Fuel injection pressure adjustment 9
3.4 Oil pressure adjustment 10
4 Employment of diesel engine 11
4.1 Selection of fuel, lubricating oil and coolant 11
4.1.1 Fuel 11
4.1.2 Oil 11
4.1.3 Coolant 11
4.2 Preparations before starting the diesel engine 12
4.3 Starting the diesel engine 12
4.3.1. Procedures of starting the diesel engine 12
4.3.2. Check following items after start 12
4.4 Operating the diesel engine 13
4.4.1 Requirements of using engine 13
4.4.2 Points that always need careful check when engine is running 13
4.5 Stopping the diesel engine 14
4.6 Storage 14
5 Diesel engine maintenance 14
5.1 Break-in of the diesel engine 14
5.2 Requirements of technical maintenance 15
5.3 Maintenance methods 16
5.3.1 Check and replace the lubricating oil 16
5.3.2 De-aerate the fuel in the fuel pipe 17
5.3.3 Check and adjust the belt tension 17
5.3.4 Discharge the coolant 17
5.3.5 Clean the inlet screen of the oil pump 17
5.3.6 Clean the air cleaner 18
5.3.7 Add lubricating grease 18
5.3.8 Scrub the water deposit off. 19
6 Troubleshooting 19
6.1 Diesel engine can not start 19
6.2 Insufficient power output 20
6.3 Abnormal noise during engine operation 21
6.4 Exhaust with abnormal smoke color 21
6.5 Too low oil pressure 22
6.6 Too high oil pressure, much diluted oil, excessive oil consumption 23
6.7 Too high water outlet temperature 23
6.8 Engine stops by itself 23
6.9 Engine over-speeding（Speed rises sharply） 24
6.10 Common trouble and troubleshooting remedies for injection pump 24
6.11 Common trouble and troubleshooting remedies for governor 25
6.12 Common trouble for fuel supply pump 25
6.13 Common trouble and troubleshooting remedies for injector 26
1 Engine specifications and accessories
1.1 Engine specifications
No. / Name / Specifications1 / Model code / YC4108 / YC4108ZQ
2 / Type / vertical, in-line, liquid-cooled and four-stroke engine
3 / Liner / wet type
4 / Combustion chamber / directing injection and reentrant ωtype
5 / Intake / natural aspirated / turbocharged
6 / Cylinder number / 4
7 / Cylinder bore (mm) / 108
8 / Stroke (mm) / 115
9 / Displacement / 4.214
10 / Compression ratio / 17:1
11 / Rated power (kW) / 40 / 50
12 / Rated speed (r/min) / 1500
13 / Rated fuel consumption (g/kW.h) / ≤240 / ≤230
14 / Min. continous idle speed (r/min) / ≤700
15 / Steady speed regulation (％) / ≤5
16 / Transient speed regulation (％) / ±10
17 / Stabilizing time (s) / ≤7
18 / Speed fluctuation (％) / 1
19 / Oil consumption (g/kW.h) / ≤1.8
20 / Soot (BSU) / ≤4.0
21 / Exhaust temperature (℃) / ≤550
22 / Noise limit [dB(A)] / ≤108 / ≤109
23 / Fire order / 1-3-4-2
24 / Piston average speed(m/s) / 5.75
25 / Rotation direction of crankshaft / counterclockwise (face to output end)
26 / Lubrication system / combination of splash and pressure
27 / Cooling system / pressurized circulating liquid cooling
28 / Start system / 24v electric
29 / Net weight (kg) / 360 / 370
30 / Dimensions (length×width×height) (mm) / 870×670×780 / 870×670×800
1.2 Technical data of adjustment and control for engine
Item / YC4108D / YC4108ZDOil pressure / at rated speed / 0.25～0.6
at idle speed
Oil temperature(℃) / ≤100
Cooling water outlet temperature(℃) / 75-95
Static fuel supply advance angle (ºCA ) / 14±2 before TDC
Cold valve clearance (ºCA) / Intake valve / 0.40±0.05
Exhaust valve / 0.45±0.05
Valve timing (ºCA) / Intake valve advance open angle / 14
Exhaust valve lag close angle / 44
Exhaust valve advance open angle / 56
Intake valve lag close angle / 12
Valve recession height (mm) / 1±0.2
Protrusion height of fuel injector over cylinder head bottom surface (mm) / 3.6±0.1
Cylinder compression clearance (mm) / 1±0.1
Oil volume (L) / 12(11 in oil sump)
1.3 Tightening torques of the connecting screw thread
1 Tightening torques of main bolts and nuts are shown below:
Description / Tightening torque(N•m) / Description / Tightening torque(N•m)Cylinder head bolt / 210-250 / Flywheel bolt / 170-210
Main bearing bolt / 220-260 / Crankshaft belt pulley fastening bolt / ≥300
Connecting rod bolt / 160-200 / Camshaft gear locking bolt / ≥300
2 Except for the important connecting screw thread, tightening torque of other bolts and nuts can be selected according to the table below:
Screw thread specifications / M6 / M8 / M10 / M12 / M14Tightening torque(N.m) / 10-20 / 20-30 / 35-55 / 70-90 / 110-130
1.4 Main parts fit clearances
No. / Description / Prescribed dimensions (mm) / Type of fit / Assembly tolerance (mm)1 / Exhaust valve seat insert/exhaust valve / Φ44.5/Φ44.5 / interference / 0.045~0.095
2 / Intake valve seat insert/exhaust seat / Φ48.5 //Φ48.5 / interference / 0.089~0.139
3 / Valve guide/cylinder head valve guide hole / Φ16/Φ16 / interference / 0.010~0.046
4 / Valve guide/exhaust valve stem / Φ9.5/Φ9.5 / radial clearance / 0.040~0.081
5 / Valve guide/intake valve stem / Φ9.5/Φ9.5 / radial clearance / 0.025～0.066
6 / Rocker arm bush/ rocker arm shaft / Φ25 /Φ25 / radial clearance / 0.0200.062
7 / Cylinder bore/diameter of the lower part of the piston skirt / Φ108Φ107.860.01 / radial clearance / 0.130~0.172
8 / Valve tappet/cylinder block tappet hole / Φ28.0~28.052/Φ27.959～27.98 / radial clearance / 0.020~0.093
9 / Camshaft bearing bore in cylinder block /camshaft bearing bush / Φ62.0~62.03/Φ62.087～62.106 / interference / 0.057~0.106
10 / Camshaft bearing bush/camshaft journal / Φ58.50~58.03/Φ58.44~58.47 / radial clearance / 0.03~0.09
11 / Timing idle gear bush/idle gear shaft / Φ55.5~55.53/Φ55.44~55.47 / radial clearance / 0.03~0.09
12 / Timing idle gear/idle gear shaft / 27.92~28.0/28.07~28.17 / axial clearance / 0.07~0.25
13 / Top ring groove height/top gas ring height / 2.6950.015/ 2.605 / axial clearance / 0.085~0.135
14 / Second ring groove height/second gas ring height / 2.5/2.5 / axial clearance / 0.09~0.125
15 / Oil ring groove height /oil ring height / 3.5/ 3.5 / axial clearance / 0.030~0.065
16 / Connecting rod bearing (with shell)/crankpin / Φ66/Φ66 / radial clearance / 0.040~0.108
17 / Connecting rod bush/piston pin / Φ38/Φ38 / radial clearance / 0.025~0.047
18 / Piston pin/pin boss / Φ38/Φ38 / radial clearance / 0.005~0.023
Φ40/Φ40 (turbocharged) / 0.005~0.076
19 / Cylinder block main bearing (with shell) /crankshaft journal / Φ85 /Φ85 / radial clearance / 0.060~0.144
20 / Camshaft spacer/thrust disk / 5/5 / axial clearance / 0.10~0.20
21 / Width of the oil pump rotor /depth of bore in oil pump body / 22/22 / axial clearance / 0.05~0.101
22 / Outer diameter of outer rotor/ bore in oil pump body / Φ69.7/Φ69.8 / radial clearance / 0.15~0.33
23 / Oil pump shaft bushing(I)/oil pump shaft / Φ19/Φ19 / radial clearance / 0.025~0.063
24 / Oil pump shaft bushing(II)/oil pump shaft / Φ15.8/Φ15.8 / radial clearance / 0.026~0.063
25 / End gap when ring inserted in gauge / top gas ring
second gas ring
oil ring / clearance
clearance
clearance / 0.4~0.6
0.35~0.55
0.30~0.55
26 / Crankshaft axial clearance / axial clearance / 0.1~0.27
27 / Backlash of gear in mesh / gear backlash / 0.07~0.25
1.5 Specifications of main parts and accessories
No. / name / type / model codeYC4108D / YC4108ZD
1 / Fuel injection pump assembly / model code / 4JI203 / 4JI204
type / in-line plunger pump / in-line plunger pump
plunger diameter / φ9.5mm / φ9.5mm
plunger stroke / 9mm / 9mm
governor type / mechanical variable-speed governor / mechanical variable-speed governor
2 / Fuel injector assembly / model code / CKBL685004 / CKBL685004
type / long multi-hole nozzle / long multi-hole nozzle
precision pairs type / ZCK155S529 / ZCK155S529
injection pressure / 23±0.5MPa / 23±0.5MPa
3 / Fuel filter / CX0710 paper element and rotation
4 / Oil filter / CX0818 paper element and rotation
5 / Thermostat / model code : 145
type : wax
opening temperature : 70±2℃
full opening temperature 78±2℃
6 / Fan / φ450 axial flow
7 / Starter generator / voltage : 24V
power : 4.8kW
8 / Charging generator / voltage : 28V
power : 750kW
9 / Belt / 8PK1760 V-ribbed belt used in vehicle
10 / Turbocharger / TB28
2 Main installing requirements
2.1 Installation of the crankshaft
During crankshaft installation, the main bearing bolts should be tightened from thrust gear (the third gear) to both ends in order, and in three steps:
1
First, tighten to 60~80N.m;
Then, tighten to 160~180N.m;
Finally, tighten to 220~260N.m.
During every time, the crankshaft should be rotated to check the mobility. It should be able to rotate freely after the final tightening. The axial clearance should be between 0.1 and 0.27mm.
Figure 1 Tightening order of the main bearings
1
2.2 Installations of the piston and the connecting rod
1
When installing the piston rings, put the surfaces marked upward (the second positive twist ring inner fillet upward). During positioning the piston-connecting rod assembly into the cylinder bore, stagger the joints in turn as shown in Figure 2, and put the arrow marked on the top surface of piston towards the front end of the engine. Remember spreading some clean oil before tightening connecting-rod bolts. The tightening torque should be between 160~200N.m, and completed in three steps:
First, tighten to 50~70N.m;
Then, tighten to 100~120N.m;
Finally, tighten to 160~200N.m.
Figure 2 Orientation of the gap of piston rings
1
2.3 Installation of the camshaft
1
Position the camshaft into the cylinder body with caution to make sure not scratch the surfaces of the journals, cams, and liners. And then install the circlip, cam thrust plate, cam gear, and cam retainer. Finally, tighten fastening bolt with more than 300N.m tightening torque. The camshaft should be able to rotate freely, and its axial clearance is between 0.1~0.2mm.
Figure 3 Camshaft axial clearance
1
2.4 Installation of the valves and valve guides
1
The valve guides should be pressed in at normal state with 20±0.3mm distances between their top surfaces and the surfaces of the cylinder head spring seats. Both the valve face angles of intake and exhaust valves are 45°. The valves and valve seat inserts should be grinded in pair, and checked through kerosene. It must be guaranteed that kerosene don’t leak within three minutes. The valve recession heights of the valves should be between 1±0.2mm.
Figure 4 Installation of the valves and valve guides
1
2.5 Installation of the injectors
1
Before mounting the cylinder head, the injectors should be installed in the cylinder head first. The nozzles should protrude 3.4±0.1mm from the bottom surface of the cylinder head, which can be ensured by adjusting the width of the injector washer. And then remove the injectors to prepare for following installation. As long as adjusted, the injectors and washers cannot be exchanged during installation.
Figure 5 Installation of the injector
1
2.6 Installation of the cylinder head
During cylinder head installation, the cylinder head bolts should be tightened to a tightening torque of between 210~250N.m and following the sequence shown in Figure 6 in three steps:
1
First, tighten to 60~80N.m;
Then, tighten to 120~140N.m;
Finally, tighten to 210~250N.m.
Figure 6 Tightening order of the cylinder bolts
1
2.7 Installation of the gear train
1
The crankshaft timing gear, injection pump gear, and camshaft gear should all be accordance with the timing requirement, so there are timing marks, which should be aligned during installing the gears, on them and timing idle gear. Oil the tooth surface after installing. The range of the gear meshing clearance is between 0.07~0.25mm.
Figure 7 Installation of the gear system
1
Caution
1. Every component should be cleaned before being installed, especially the oil passages, no dirt is permitted in them.
2. No corrosion, burr, or scratch is permitted on the fit surfaces of every component.
3. Friction surfaces and important fit surfaces should be oiled before installing.
4. Fit clearance (or interference) should be accordance with the requirement offered in the main fit clearance (or interference) in chapter 1.
3 Engine adjustment
3.1 Fuel supply advance angle adjustment
Technical data : Static fuel supply advance angle is 14±2℃A before TDC.
Fuel supply advance angle check: Unscrew the nut which connects the high pressure fuel line for the No.1 cylinder and fuel injection pump, crank the crankshaft slowly until the fuel level in the delivery valve holder begins to fluctuate. At this time, the timing value indicated by the pointer on the gear housing and the dial on the belt pulley damper is the fuel supply advance angle.