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Doosan DL03 Engine

The Doosan DL03 (also designated as the D34 or DM03) is an industrial-grade, 3.4-liter, in-line 4-cylinder, 4-cycle diesel engine widely deployed in compact construction equipment, material handling machinery, and utility tractors. Engineered to comply with Tier 4 Final and EU Stage V emissions standards, it utilizes a highly efficient direct-injection combustion design complemented by turbocharging and air-to-air charge air cooling (intercooled). The engine features a robust, linerless cylinder block design to balance structural durability with a compact footprint, eliminating the need for a Diesel Particulate Filter (DPF) in certain configurations through optimized exhaust treatment paths.

The cylinder head utilizes an overhead valve configuration incorporating 4 valves per cylinder (16 valves total), maximizing gas exchange efficiency and volumetric optimization within the combustion chamber. The engine features a cylinder diameter (bore) of 98 mm and a piston travel distance (stroke) of 113 mm, yielding a total displacement volume of exactly 3409 cc (3.4 liters) with a nominal compression ratio of 17.0:1 to 18.0:1.

Fuel System: Fuel delivery is managed via an electronically controlled, High-Pressure Common Rail (HPCR) injection system fueled by a Delphi DFP 4.2 injection pump or a Bosch equivalent system operating at injection pressures up to 1800 bar. The electronic control unit (ECU) dynamically monitors fuel pressure and commands multi-hole type injection nozzles to optimize timing and atomization based on real-time load requirements. The secondary supply circuit utilizes a full-flow cartridge fuel filter housing meeting EN590 diesel specifications.

The lubrication configuration relies on a fully forced pressure feed system driven by a crankshaft-mounted, gear-type oil pump. Engine oil is pulled from the oil pan and pushed through a replaceable, full-flow cartridge filter element. Minimum oil pressure under normal operating conditions is rated at 43.5 psi (300 kPa). The cooling architecture relies on a freshwater forced circulation system regulated by a centrifugal water pump. It features a dual-circulation layout configured to optimize thermal dissipation under extreme loads, keeping power attenuation under 5% in high-ambient environments. The system routes engine coolant directly through the engine block, oil cooler jackets, and the charge air cooler (CAC) assembly.

General Technical Data

Engine Specifications

Engine Model ............... Doosan DL03
Engine Family Identification ............... GDICLO3.4LEA
Engine Series Designator ............... D34P / D34
Engine Type ............... 4-cycle inline 4-cylinder direct injection liquid-cooled diesel
Number of Cylinders ............... 4
Cylinder Arrangement ............... In-line
Engine Bore, in (mm) ............... 3.86 (98.0)
Engine Stroke, in (mm) ............... 4.45 (113.0)
Displacement, cu.in (L) ............... 208.0 (3.409)
Rated Engine Power, hp (kW) ............... 80.0-105.0 (59.7-78.3) at 2200-2300 rpm
Low Idle Engine Speed, rpm ............... 750-850
High Idle Engine Speed, rpm ............... 2400-2550
Peak Torque, lb-ft (Nm) ............... 273.0-317.0 (370.0-430.0) at 1400 rpm
Operating Speed Range, rpm ............... 1400-2300
Compression Ratio ............... 17.0:1
Firing Order ............... 1-3-4-2
Aspiration Configuration ............... Turbocharged and charge air cooled
Turbocharger Cooling ............... Oil cooled and integrated air jacket system
Engine Rotation Direction ............... Counter-clockwise viewed from the flywheel side
Combustion Chamber ............... Direct injection re-entrant bowl type
Valve Mechanism Type ............... Overhead valve with pushrods and rocker arms
Number of Valves per Cylinder ............... 4
Total Number of Valves ............... 16
Cylinder Block Material ............... Cast iron alloy with deep skirt design
Cylinder Head Material ............... Cast iron alloy with cross-flow port arrangement
Crankshaft Material ............... Forged steel alloy with induction hardened journals
Lubrication System ............... Full-pressure circulation system with rotor gear pump
Oil Pump Drive Mechanism ............... Gear-driven from the crankshaft gear
Oil Filter Type ............... Full-flow spin-on cartridge filtration assembly
Oil Cooler Type ............... Liquid-cooled plate matrix integrated inside the block
Cooling System ............... Forced circulation liquid cooling with centrifugal pump
Water Pump Drive ............... Poly-V belt driven from the crankshaft pulley
Air Cleaner Type ............... Dry type dual element with dust indicator sensor
Emission Certification ............... EPA Tier 4 Final / EU Stage IV and Stage V
Exhaust Aftertreatment ............... SCR with DOC
Exhaust Gas Recirculation ............... Cooled external exhaust gas recirculation
Crankcase Ventilation Type ............... Closed crankcase ventilation with oil separator
Starting System ............... Electrical starter motor
Starter Rating, hp (kW) ............... 4.56 (3.4)
Electrical System, V ............... 12
Alternator Output, A ............... 90 or 100

Fuel System

Injection Management Type ............... High pressure common rail electronic system
Fuel Injection Pump Model ............... Bosch CP4.2 twin plunger high pressure pump
Fuel Rail Maximum Operating Pressure, psi (bar) ............... 26100.0 (1800.0)
Fuel Rail Normal Idle Pressure, psi (bar) ............... 4350.0 (300.0)
Fuel Injector Assembly Type ............... Solenoid controlled multi-hole electronic fuel injectors
Number of Injector Spray Orifices ............... 8
Fuel Injector Actuation Control ............... ECU multi-stage injection sequencing
Fuel Feed Pump Supply Type ............... Electric or mechanical gear type transfer pump
Fuel Transfer Pump Delivery Pressure, psi (bar) ............... 65.0-87.0 (4.5-6.0)
Fuel Return Line Maximum Back Pressure, psi (bar) ............... 14.5 (1.0)
Fuel Lift Pump Suction Lift Maximum, in (mm) ............... 19.68 (500.0)
Fuel Injection Line Wall Thickness, in (mm) ............... 0.078 (2.0)
Fuel Injection Line Outer Diameter, in (mm) ............... 0.236 (6.0)
Fuel Rail Pressure Sensor Voltage Supply, V ............... 5.0
Fuel Rail Pressure Sensor Signal Range, V ............... 0.5-4.5
Fuel Temperature Operational Limit, F (C) ............... 176.0 (80.0)
Recommended Fuel Grade ............... Ultra Low Sulfur Diesel meeting ASTM D975 S15
Fuel Filter Water Separator Capacity, cu.in (L) ............... 12.2 (0.2)
Fuel Rail Safety Limiter Valve Crack Pressure, psi (bar) ............... 29000.0 (2000.0)
Fuel Inlet Supply Hose Inside Diameter, in (mm) ............... 0.315 (8.0)
Fuel Return Hose Inside Diameter, in (mm) ............... 0.236 (6.0)

Dimensions and Weight

Overall Length, in (mm) ............... 31.5 (800)
Overall Width, in (mm) ............... 24.8 (630)
Overall Height, in (mm) ............... 33.4 (850)
Dry Weight, lbs (kg) ............... 662 (300)
Wet Weight, lbs (kg) ............... 706 (320)

Maintenance Data

Service Information

Oil Pressure at Rated Speed, psi (kPa) ............... 43.5-65.2 (300.0-450.0)
Oil Pressure at Low Idle, psi (kPa) ............... 14.5-20.3 (100.0-140.0)
Relief Valve Opening Pressure, psi (kPa) ............... 72.5-87.0 (500.0-600.0)
Radiator Cap Release Pressure, psi (kPa) ............... 13.0-15.0 (90.0-103.0)
Maximum Oil Temperature, F (C) ............... 248.0 (120.0)
Thermostat Opening Temperature, deg F (deg C) ............... 180.0 (82.0)
Thermostat Full Open Temperature, deg F (deg C) ............... 203.0 (95.0)
Poly-V Drive Belt Tension Deflection, in (mm) ............... 0.31-0.47 (8.0-12.0)
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 5W-40, SAE 10W-30, or 15W-40
API Service Classifications ......................... CJ-4 or CK-4
Engine Oil Capacity with Filter, qt (L) ............... 11.1 (10.5)
Engine Oil Capacity (Low Level), qt (L) ............... 8.9 (8.5)
Coolant Capacity (Engine Block), qt (L) ............... 6.3 (6.0)
Coolant System Capacity (Total), qt (L) ............... 14.7 (14.0)

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 1500 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) ............... 3.8582-3.8586 (98.000-98.010)
Cylinder Bore Max Out-of-Round, in (mm) ............... 0.00039 (0.010)
Connecting Rod Small End Bushing I.D, in (mm) ............... 1.3391-1.3397 (34.015-34.030)
Crankshaft Main Journal Diameter Standard, in (mm) ............... 3.1492-3.1500 (79.990-80.010)
Crankshaft Main Journal Taper Maximum, in (mm) ............... 0.00019 (0.005)
Crankshaft Main Bearing Clearance, in (mm) ............... 0.0015-0.0033 (0.040-0.085)
Connecting Rod Journal Diameter, in (mm) ............... 2.3618-2.3626 (59.990-60.010)
Connecting Rod Bearing Clearance, in (mm) ............... 0.0013-0.0031 (0.035-0.080)
Crankshaft Axial End Play, in (mm) ............... 0.0039-0.0118 (0.100-0.300)
Connecting Rod Side Clearance, in (mm) ............... 0.0059-0.0118 (0.150-0.300)
Piston Skirt Outside Diameter, in (mm) ............... 3.8551-3.8559 (97.920-97.940)
Piston-to-Cylinder Bore Clearance, in (mm) ............... 0.0023-0.0035 (0.060-0.090)
Piston Pin Bore Inner Diameter, in (mm) ............... 1.3386-1.3389 (34.002-34.010)
Piston Pin Outer Diameter, in (mm) ............... 1.3383-1.3385 (33.994-34.000)
Piston Pin to Piston Pin Bore Clearance, in (mm) ............... 0.00007-0.00062 (0.002-0.016)
Piston Pin to Con Rod Bushing Clearance, in (mm) ............... 0.00059-0.00141 (0.015-0.036)
Top Ring Groove Width, in (mm) ............... 0.0826-0.0834 (2.100-2.120)
Second Ring Groove Width, in (mm) ............... 0.0799-0.0807 (2.030-2.050)
Oil Ring Groove Width, in (mm) ............... 0.1189-0.1197 (3.020-3.040)
Top Ring Side Clearance, in (mm) ............... 0.0027-0.0043 (0.070-0.110)
Second Ring Side Clearance, in (mm) ............... 0.0019-0.0035 (0.050-0.090)
Oil Ring Side Clearance, in (mm) ............... 0.0011-0.0027 (0.030-0.070)
Top Ring End Gap, in (mm) ............... 0.0098-0.0157 (0.250-0.400)
Second Ring End Gap, in (mm) ............... 0.0137-0.0216 (0.350-0.550)
Oil Ring End Gap, in (mm) ............... 0.0098-0.0196 (0.250-0.500)
Cylinder Head Bottom Surface Flatness, in (mm) ............... 0.0019 (0.050)
Cylinder Block Top Surface Flatness, in (mm) ............... 0.0019 (0.050)
Intake Valve Stem Outer Diameter, in (mm) ............... 0.2740-0.2748 (6.960-6.980)
Exhaust Valve Stem Outer Diameter, in (mm) ............... 0.2732-0.2740 (6.940-6.960)
Valve Guide Inner Diameter, in (mm) ............... 0.2755-0.2763 (7.000-7.020)
Intake Valve Stem to Guide Clearance, in (mm) ............... 0.0007-0.0023 (0.020-0.060)
Exhaust Valve Stem to Guide Clearance, in (mm) ............... 0.0015-0.0031 (0.040-0.080)
Intake Valve Seat Width, in (mm) ............... 0.0472-0.0629 (1.200-1.600)
Exhaust Valve Seat Width, in (mm) ............... 0.0551-0.0708 (1.400-1.800)
Valve Seat Angle, deg ............... 45.0
Valve Face Angle, deg ............... 45.5
Valve Spring Free Length, in (mm) ............... 1.9291 (49.000)
Camshaft Journal Outer Diameter (Journal 1), in (mm) ............... 1.9665-1.9673 (49.950-49.970)
Camshaft Journal Outer Diameter (Journal 2), in (mm) ............... 1.9271-1.9279 (48.950-48.970)
Camshaft Journal Outer Diameter (Journal 3), in (mm) ............... 1.8877-1.8885 (47.950-47.970)
Camshaft Journal Clearance, in (mm) ............... 0.0011-0.0029 (0.030-0.075)
Camshaft End Play, in (mm) ............... 0.0027-0.0070 (0.070-0.180)
Cam Lobe Height (Intake), in (mm) ............... 1.6141-1.6220 (41.000-41.200)
Cam Lobe Height (Exhaust), in (mm) ............... 1.6535-1.6614 (42.000-42.200)
Rocker Arm Inner Bushing Diameter, in (mm) ............... 0.7483-0.7491 (19.008-19.030)
Rocker Arm Shaft Outer Diameter, in (mm) ............... 0.7468-0.7476 (18.970-18.990)
Rocker Arm Bushing to Shaft Clearance, in (mm) ............... 0.0007-0.0023 (0.018-0.060)
Idler Gear to Camshaft Gear Backlash, in (mm) ............... 0.0027-0.0066 (0.070-0.170)
Idler Gear Bushing Inner Diameter, in (mm) ............... 1.7723-1.7731 (45.016-45.035)
Idler Gear Shaft Outer Diameter, in (mm) ............... 1.7704-1.7711 (44.968-44.985)
Idler Gear Bushing to Shaft Clearance, in (mm) ............... 0.0012-0.0026 (0.031-0.067)

Tightening Torques

Cylinder Head Bolt (1-Step), lb-ft (Nm) ............... 36.8 (50.0)
Cylinder Head Bolt (2-Step), lb-ft (Nm) ............... 73.7 (100.0) + 90 deg turn
Main Bearing Cap Bolt (1-Step), lb-ft (Nm) ............... 44.2 (60.0) + 90 deg turn
Connecting Rod Cap Bolt (1-Step), lb-ft (Nm) ............... 22.1 (30.0)
Connecting Rod Cap Bolt (2-Step), lb-ft (Nm) ............... 44.2 (60.0) + 90 deg turn
Flywheel Mounting Bolt (1-Step), lb-ft (Nm) ............... 29.5 (40.0)
Flywheel Mounting Bolt (2-Step), lb-ft (Nm) ............... 59.0 (80.0)
Crankshaft Main Center Pulley Damper Bolt , lb-ft (Nm) ............... 191.7 (260.0)
Camshaft Gear Center Lock Bolt, lb-ft (Nm) ............... 77.4 (105.0)
Camshaft Thrust Plate Lock Bolt, lb-ft (Nm) ............... 18.4 (25.0)
Idler Gear Support Shaft Assembly Bolt, lb-ft (Nm) ............... 55.3 (75.0)
Timing Gear Case Cover Housing Bolt (M8), lb-ft (Nm) ............... 18.4 (25.0)
Timing Gear Case Cover Housing Bolt (M10), lb-ft (Nm) ............... 36.8 (50.0)
Rocker Arm Shaft Stand Support Holding Nut, lb-ft (Nm) ............... 22.1 (30.0)
Rocker Arm Valve Clearance Adjusting Lock Nut, lb-ft (Nm) ............... 14.7 (20.0)
Rocker Valve Cylinder Head Cover Bolt, lb-ft (Nm) ............... 8.8 (12.0)
Oil Pan Base Bottom Drain Plug, lb-ft (Nm) ............... 36.8 (50.0)
Oil Pan Steel Mounting Flange Bolt, lb-ft (Nm) ............... 18.4 (25.0)
Oil Pump Assembly Housing Mounting Bolt, lb-ft (Nm) ............... 18.4 (25.0)
Oil Cooler Assembly Cover Bolt, lb-ft (Nm) ............... 18.4 (25.0)
Water Pump Base Housing Mounting Bolt, lb-ft (Nm) ............... 18.4 (25.0)
Thermostat Outbound Pipe Housing Sealing Bolt, lb-ft (Nm) ............... 18.4 (25.0)
Intake Manifold Assembly Mounting Flange Bolt, lb-ft (Nm) ............... 18.4 (25.0)
Exhaust Manifold Assembly High Temp Nut, lb-ft (Nm) ............... 33.1 (45.0)
Turbocharger Exhaust Turbine Flange Nut, lb-ft (Nm) ............... 36.8 (50.0)
Turbocharger Oil Feed Supply Hose Bolt, lb-ft (Nm) ............... 22.1 (30.0)
Turbocharger Oil Return Flange Bottom Bolt, lb-ft (Nm) ............... 8.8 (12.0)
High Pressure Injection Pump Drive Gear Nut, lb-ft (Nm) ............... 66.3 (90.0)
High Pressure Fuel Pump Flange Bolt, lb-ft (Nm) ............... 22.1 (30.0)
Fuel Injector Hold Down Clamp Bolt, lb-ft (Nm) ............... 22.1 (30.0)
High Pressure Fuel Injection Distribution Bolt, lb-ft (Nm) ............... 22.1 (30.0)
High Pressure Fuel Supply Injection Pipe Nut, lb-ft (Nm) ............... 25.8 (35.0)
Fuel Pre-Filter Assembly Base Mounting Screw, lb-ft (Nm) ............... 18.4 (25.0)
ECM Chassis Mounting Bolt, lb-ft (Nm) ............... 7.3 (10.0)
Flywheel Outer Bell Housing Bolt (M10), lb-ft (Nm) ............... 36.8 (50.0)
Flywheel Outer Bell Housing Bolt (M12), lb-ft (Nm) ............... 64.9 (88.0)
EGR Cooler Block Flange Bolt, lb-ft (Nm) ............... 18.4 (25.0)
EGR Valve Actuator Housing Bolt, lb-ft (Nm) ............... 18.4 (25.0)
Crankcase Breather Ventilation Cover Bolt, lb-ft (Nm) ............... 7.3 (10.0)
Starter Motor Frame Flange Mounting Bolt, lb-ft (Nm) ............... 59.0 (80.0)
Alternator Bracket Adjuster Lock Tension Bolt, lb-ft (Nm) ............... 33.1 (45.0)
Oil Pressure Sensor Switch, lb-ft (Nm) ............... 14.7 (20.0)
Coolant Temperature Sensor, lb-ft (Nm) ............... 22.1 (30.0)
Air Temperature Pressure Combo Sensor, lb-ft (Nm) ............... 7.3 (10.0)
High Temperature Sensor Union Screw, lb-ft (Nm) ............... 33.1 (45.0)
Glow Plug Internal Combustion Fitting, lb-ft (Nm) ............... 11.0 (15.0)
Glow Plug Top Electrical Wire Harness Nut, lb-ft (Nm) ............... 1.4 (2.0)
Oil Spray Piston Cooling Jet Nozzle Bolt, lb-ft (Nm) ............... 22.1 (30.0)
Front Crankshaft Oil Seal Carrier Housing Bolt, lb-ft (Nm) ............... 8.8 (12.0)
Rear Crankshaft Oil Seal Carrier Housing Bolt, lb-ft (Nm) ............... 8.8 (12.0)
Fan Drive Pulley Assembly Hub Shaft Bolt, lb-ft (Nm) ............... 33.1 (45.0)
Air Compressor Accessory Drive Gear Bolt, lb-ft (Nm) ............... 55.3 (75.0)

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• Doosan Engines Specs
  
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• Doosan DL02 Specs
  
• Doosan DM02P Specs
  
• Doosan DM02VB Specs
  

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