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Doosan DL08 Engine

The Doosan DL08 is a heavy-duty, industrial-grade inline 6-cylinder diesel engine widely utilized in construction machinery (such as wheel loaders and excavators), commercial buses, and stationary industrial applications. Developed by Doosan Infracore, this 4-stroke, water-cooled powerplant incorporates a turbocharger and an air-to-air intercooler system to meet stringent emission standards while delivering high torque at low engine speeds. The engine features an overhead valve structure, direct fuel injection with electronic control, and a robust architecture engineered for durability, low noise, and maximum fuel economy.

Valve Configuration: Overhead valve mechanism (OHV) driven by a gear-driven camshaft. Valves per Cylinder: 4 valves per cylinder (2 intake valves, 2 exhaust valves) to improve volumetric efficiency. Injector Placement: Vertically mounted central injectors positioned directly over the combustion bowl. Cylinder Bore: 108 mm. Piston Stroke: 139 mm. Compression Ratio: between 16.8:1 and 17:1.

Fuel System: High-pressure Common Rail System (CRS) featuring an electronically controlled injection profile. Fuel Injection: Fuel is drawn from the supply tank via a low-pressure transfer pump, routed through primary and secondary multi-stage fuel filters to strip out moisture and debris, and then fed into a high-pressure injection pump. Electronic Control Unit (ECU): The ECU manages exact injection timing, multi-pulse injection duration, and fuel rail pressure based on real-time sensor data. Fuel is dispersed directly into the cylinder bowl via high-pressure injectors, maximizing thermal efficiency while minimizing soot formation.

Lubrication System: Full-force pressure lubrication fed by a gear-type oil pump driven directly from the crankshaft gear train. Filtration: Utilizes a spin-on full-flow oil filter assembly combined with a bypass filtration circuit to trap micro-particles. Cooling: An integrated plate-type engine oil cooler is submerged within the main engine coolant jacket to stabilize oil temperature during heavy operation.

Cooling System: Forced-circulation water cooling system regulated by a heavy-duty centrifugal water pump. Temperature Regulation: Wax-pellet type thermostats govern flow between the bypass circuit and the radiator matrix to optimize warm-up periods and maintain steady engine operation. Charge Air Cooling: Air-to-air intercooling (aftercooler) drops the temperature of the air leaving the turbocharger before it reaches the intake manifold, increasing oxygen density for combustion.

General Technical Data

Engine Specifications

Engine Model ............... Doosan DL08
Engine Type ............... 4-cycle inline 6-cylinder direct injection liquid-cooled diesel
Number of Cylinders ............... 6
Cylinder Arrangement ............... In-line
Engine Bore, in (mm) ............... 4.25 (108.0)
Engine Stroke, in (mm) ............... 5.47 (139.0)
Displacement, cu.in (L) ............... 466.2 (7.64)
Rated Engine Power, hp (kW) ............... 217-340 (162-250) at 2000-2200 rpm
Maximum Engine Power, hp (kW) ............... 227-350 (169-257) at 1800-2200 rpm
Peak Torque ............... 883-1470 Nm (651-1084 lb-ft) at 1200-1300 rpm
Low Idle Speed, rpm ............... 750-850
High Idle Speed, rpm ............... 2300-2450
Compression Ratio ............... 16.5:1-17.4:1
Firing Order ............... 1-5-3-6-2-4
Aspiration Type ............... Turbocharged and air-to-air intercooled
Turbocharger Type ............... Wastegate or Variable Geometry Turbocharger (VGT)
Intercooler Type ............... Air-to-air charge air cooler
Combustion Chamber Type ............... Direct injection type
Cylinder Liner Type ............... Replaceable dry liner
Timing Gear System ............... Gear driven type
Number of Piston Rings ............... 2 compression rings, 1 oil ring
Valves per Cylinder ............... 4 (2 intake, 2 exhaust)
Valve System Type ............... Over Head Valve (OHV)
Cylinder Block Material ............... Cast iron
Cylinder Head Material ............... Cast iron
Piston Material ............... Aluminum alloy with oil gallery cooling
Lubrication Method ............... Fully forced pressure feed type
Oil Pump Type ............... Gear-driven rotary type
Cooling Method ............... Liquid-cooled forced circulation
Water Pump Type ............... Belt-driven centrifugal type
Thermostat Type ............... Wax-pellet type with bypass
Air Cleaner Type ............... Dry dual-stage element with evacuator valve
Aftertreatment Configuration ............... DOC + DPF + SCR
Starting System ............... Electric starter motor
Electrical System ............... 24V
Alternator Capacity ............... 80A or 100A

Fuel System

Injection System Type ............... Electronic Common Rail System (CRDI)
High Pressure Injection Pump ............... Bosch CP3.3
Fuel Metering Unit Actuation ............... Open below 8V, closed above 8V
Feed Pump Type ............... Gear driven type
Injection Nozzle Type ............... Multi-hole vertical injector
Maximum Common Rail Pressure, bar (psi) ............... 1600-1800 (23200-26100)
Rail Pressure Limiter Valve Setting, bar (psi) ............... 1750 (25380)
Rail Pressure Sensor Type ............... Bosch RDS3
Fuel Filter Type ............... Full flow cartridge type
Primary Fuel Filter Micron Rating, microns ............... 10
Secondary Fuel Filter Micron Rating, microns ............... 3
Engine Control Unit (ECU) ............... Bosch EDC7UC31
Limp Home Rail Pressure, bar (psi) ............... 400-500 (5800 - 7250)
Permissible Fuel Oil Type ............... Ultra-low sulfur diesel fuel oil
Fuel Temperature Sensor Resistance, kohms ............... 2.5 at 25C (77F)
Fuel Temperature Sensor Resistance at Max, kohms ............... 0.186 at 100C (212F)
Fuel Transfer Pump Delivery Pressure, bar (psi) ............... 5.0-6.5 (72.5-94.2)

Dimensions and Weight

Overall Length, in (mm) ............... 47.8-51.3 (1215-1305)
Overall Width, in (mm) ............... 31.5-35.7 (800-905)
Overall Height, in (mm) ............... 42.7-46.5 (1085-1180)
Dry Weight, lbs (kg) ............... 1698-1843 (770-835)
Wet Weight, lbs (kg) ............... 1820-1965 (825-890)

Maintenance Data

Service Information

Oil Pressure at Idle Speed, bar (psi) ............... 1.0-1.5 (14.5-21.7)
Oil Pressure at Rated Speed, bar (psi) ............... 3.0-5.5 (43.5-79.7)
Oil Relief Valve Opening Pressure, bar (psi) ............... 6.0-6.5 (87.0-94.2)
Oil Thermostat Opening Temperature, C (F) ............... 92 (197.6)
Thermostat Initial Opening Temperature, C (F) ............... 79-83 (174.2-181.4)
Thermostat Full Open Temperature, C (F) ............... 95 (203.0)
Intake Valve Clearance Cold, in (mm) ............... 0.012 (0.30)
Exhaust Valve Clearance Cold, in (mm) ............... 0.016 (0.40)

Engine Oil and Coolant

Engine Oil Type .................. SAE 10W-40, SAE 10W-30, or 15W-40
API Service Classifications ......................... CI-4, CJ-4, or CK-4
Engine Oil Capacity, Max Level, qt (L) ............... 29.5 (28.0)
Engine Oil Capacity Min Level, qt (L) ............... 22.2 (21.0)
Cooling Capacity, Engine Only, qt (L) ............... 14.8 (14.0)
Cooling Capacity with Radiator, qt (L) ............... 38.0-44.4 (36.0-42.0)

Service Intervals

Change oil and filter ............... Every 500 hours
Inspect air cleaner ............... Every 250 hours
Replace air cleaner ............... Every 1000 hours
Replace fuel filter ............... Every 500 hours
Valve clearance adjustment ............... Every 1000 hours
Fuel system inspection ............... Every 1000 hours
Change coolant ............... Every 2000 hours
Compression test ............... Every 1000 hours
Clean radiator core ............... Every 250 hours
Inspect belt tension ............... Every 250 hours

Service Specifications

Cylinder Bore Inside Diameter, in (mm) ............... 4.2519-4.2527 (108.000-108.022)
Cylinder Bore Roundness Limit, in (mm) ............... 0.0006 (0.015)
Cylinder Liner Projection Above Block, in (mm) ............... 0.0011-0.0027 (0.030-0.070)
Crankshaft Main Journal Diameter, in (mm) ............... 3.3838-3.3846 (85.950-85.972)
Main Bearing Oil Clearance, in (mm) ............... 0.0020-0.0048 (0.052-0.122)
Crankpin Journal Diameter, in (mm) ............... 2.7145-2.7153 (68.950-68.972)
Connecting Rod Bearing Clearance, in (mm) ............... 0.0013-0.0038 (0.034-0.098)
Crankshaft End Play, in (mm) ............... 0.0055-0.0122 (0.140-0.310)
Connecting Rod Side Clearance, in (mm) ............... 0.0063-0.0126 (0.160-0.320)
Piston Skirt Outer Diameter, in (mm) ............... 4.2484-4.2492 (107.910-107.930)
Piston to Cylinder Liner Clearance, in (mm) ............... 0.0027-0.0044 (0.070-0.112)
Piston Pin Standard Diameter, in (mm) ............... 1.5746-1.5749 (39.994-40.000)
Piston Pin to Con Rod Bushing Clearance, in (mm) ............... 0.0009-0.0018 (0.024-0.045)
Top Ring Groove Clearance, in (mm) ............... Keystone type profile keystone
Second Ring Groove Clearance, in (mm) ............... 0.0027-0.0043 (0.070-0.110)
Oil Ring Groove Clearance, in (mm) ............... 0.0015-0.0031 (0.040-0.080)
Top Ring End Gap, in (mm) ............... 0.0118-0.0177 (0.300-0.450)
Second Ring End Gap, in (mm) ............... 0.0196-0.0295 (0.500-0.750)
Oil Ring End Gap, in (mm) ............... 0.0098-0.0196 (0.250-0.500)
Cylinder Head Surface Distortion, Limit, in (mm) ............... 0.0078 (0.200)
Cylinder Block Surface Distortion, Limit, in (mm) ............... 0.0078 (0.200)
Intake Valve Stem Diameter, in (mm) ............... 0.3129-0.3137 (7.950-7.970)
Exhaust Valve Stem Diameter, in (mm) ............... 0.3118-0.3126 (7.920-7.940)
Intake Valve Stem to Guide Clearance, in (mm) ............... 0.0011-0.0027 (0.030-0.070)
Exhaust Valve Stem to Guide Clearance, in (mm) ............... 0.0023-0.0039 (0.060-0.100)
Intake Valve Seat Angle, degrees ............... 30
Exhaust Valve Seat Angle, degrees ............... 45
Valve Spring Free Length, in (mm) ............... 2.440 (62.0)
Camshaft Journal Diameter, in (mm) ............... 2.1629-2.1637 (54.940-54.960)
Camshaft End Play, in (mm) ............... 0.0051-0.0118 (0.130-0.300)
Idler Gear Bushing to Shaft Clearance, in (mm) ............... 0.0011-0.0029 (0.030-0.075)

Tightening Torques

Cylinder Head Fastener (Step 1) ............... 40 Nm (29.5 lb-ft)
Cylinder Head Fastener (Step 2) ............... 60 Nm (44.2 lb-ft) plus 180 deg rotation
Main Bearing Cap Fasteners (Step 1) ............... 150 Nm (110.6 lb-ft)
Main Bearing Cap Fasteners (Step 2) ............... 295-300 Nm (217.5-221.2 lb-ft)
Connecting Rod Cap Fasteners (Step 1) ............... 80 Nm (59.0 lb-ft)
Connecting Rod Cap Fasteners (Step 2) ............... 177-180 Nm (130.5-132.7 lb-ft)
Flywheel Mounting Fasteners ............... 255-260 Nm (188.1-191.7 lb-ft)
Crankshaft Damper Pulley Fasteners ............... 230-250 Nm (169.6-184.3 lb-ft)
Camshaft Gear Mounting Fasteners ............... 90-110 Nm (66.3-81.1 lb-ft)
Camshaft Thrust Plate Fasteners ............... 25-35 Nm (18.4-25.8 lb-ft)
Rocker Arm Shaft Bracket Fasteners ............... 45-55 Nm (33.1-40.5 lb-ft)
Cylinder Head Cover Fasteners ............... 10-15 Nm (7.3-11.0 lb-ft)
Oil Pan Drain Plug Fastener ............... 60-70 Nm (44.2-51.6 lb-ft)
Oil Pan Mounting Fasteners ............... 20-28 Nm (14.7-20.6 lb-ft)
Fuel High Pressure Common Rail Fasteners ............... 25-35 Nm (18.4-25.8 lb-ft)
Fuel High Pressure Line Nuts ............... 25-30 Nm (18.4-22.1 lb-ft)
Fuel Injector Clamp Fasteners ............... 28-32 Nm (20.6-23.6 lb-ft)
Exhaust Manifold Mounting Fasteners ............... 45-55 Nm (33.1-40.5 lb-ft)
Intake Manifold Mounting Fasteners ............... 28-35 Nm (20.6-25.8 lb-ft)
Turbocharger Mounting Fasteners ............... 45-55 Nm (33.1-40.5 lb-ft)
Water Pump Mounting Fasteners ............... 20-28 Nm (14.7-20.6 lb-ft)
Thermostat Housing Fasteners ............... 20-28 Nm (14.7-20.6 lb-ft)
Oil Pump Mounting Fasteners ............... 25-35 Nm (18.4-25.8 lb-ft)
Oil Cooler Housing Fasteners ............... 22-30 Nm (16.2-22.1 lb-ft)
Front Gear Housing Fasteners (M8) ............... 22-30 Nm (16.2-22.1 lb-ft)
Front Gear Housing Fasteners (M10) ............... 45-55 Nm (33.1-40.5 lb-ft)
Flywheel Housing Fasteners (M10) ............... 45-55 Nm (33.1-40.5 lb-ft)
Flywheel Housing Fasteners (M12) ............... 75-85 Nm (55.3-62.6 lb-ft)
Starter Motor Mounting Fasteners ............... 75-85 Nm (55.3-62.6 lb-ft)
Alternator Mounting Bracket Fasteners ............... 45-55 Nm (33.1-40.5 lb-ft)
Air Compressor Mounting Fasteners ............... 45-55 Nm (33.1-40.5 lb-ft)
Engine Mounting Bracket Fasteners ............... 180-210 Nm (132.7-154.8 lb-ft)
Fan Clutch Hub Mounting Fasteners ............... 35-45 Nm (25.8-33.1 lb-ft)
Oil Pressure Sensor ............... 15-22 Nm (11.0-16.2 lb-ft)
Coolant Temperature Sensor ............... 20-28 Nm (14.7-20.6 lb-ft)
Crankshaft Position Sensor Fastener ............... 8-12 Nm (5.9-8.8 lb-ft)
Camshaft Position Sensor Fastener ............... 8-12 Nm (5.9-8.8 lb-ft)

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• Doosan Engines Specs
  
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• Doosan DL08K Specs
  

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