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Hatz 1D50S Engine

The Hatz 1D50S is a professional-grade, air-cooled, single-cylinder, four-stroke industrial diesel engine. Belonging to the Hatz D-Series, it is engineered for heavy-duty applications in construction machinery, generators, and pumps. The "S" designation represents the standard configuration equipped with 50% first-order mass counter-balancing via weights on the crankshaft and flywheel. Structurally, it features a rugged vertical cylinder configuration with a lightweight die-cast alloy crankcase, a high-grade grey cast iron cylinder block, and a light-alloy cylinder head. The engine is known for its high power-to-weight ratio, low fuel consumption, and high operational reliability across extreme environmental conditions.

The engine employs an overhead valve (OHV) configuration. Mechanical valve actuation is driven by a gear-driven camshaft via finger followers, pushrods, and rocker arms. The system features a manual decompression device integrated into the rocker mechanism to facilitate manual cranking. Valve clearance must be checked and adjusted when the engine is cold. The cylinder architecture is configured with a bore diameter of 97 mm and a piston stroke length of 70 mm. This geometry yields a total engine displacement of 0.517 liters (517 cc).

Fuel System: Fuel delivery utilizes a high-pressure mechanical direct-injection system. The layout consists of an engine-driven high-pressure injection pump feeding fuel directly into the combustion chamber through a precise multi-hole spray nozzle. Fuel injection and speed regulation are controlled by a mechanical centrifugal governor integrated into the gear train. The system features a dedicated extra fuel start device for cold starts and requires high-quality diesel fuel conforming to EN 590, BS 2869, or ASTM D 975 specifications.

Lubrication is managed via a pressurized circulation system driven by a gear-type oil pump. The oil loop passes through a fine-mesh full-flow oil filter located in the main flow path. Minimum oil pressure at a hot idling speed of 850 RPM must be at least 0.6 bar under normal operating oil temperatures of 100C. The engine uses direct air cooling without the use of drive belts. Cooling airflow is forced across the deep cooling fins of the light-alloy cylinder head and grey iron cylinder by an integrated flywheel fan. The fan blade assembly is directly cast into the flywheel, which also encapsulates the charging alternator.

General Technical Data

Engine Specifications

Engine Model ............... Hatz 1D50S
Engine Type ............... 4-stroke single-cylinder direct injection air-cooled diesel engine
Number of Cylinders ............... 1
Engine Bore, in (mm) ............... 3.82 (97.0)
Engine Stroke, in (mm) ............... 2.76 (70.0)
Displacement, cu.in (cc) ............... 31.55 (517)
Rated Engine Power, hp (kW) ............... 5.0-10.1 (3.7-7.5)
Maximum Engine Power, hp (kW) ............... 10.6 (7.9)
Rated Engine Speed, rpm ............... 1500-3600
Peak Torque, lb-ft (Nm) ............... 18.3 (24.8) at 2500 rpm
Maximum Torque, lb-ft (Nm) ............... 20.5 (27.8)
Low Idle Speed, rpm ............... 850-950
High Idle Speed, rpm ............... 3750-3850
Aspiration Type ............... Naturally Aspirated
Compression Ratio ............... 20.5:1-21.5:1
Direction of Crankshaft Rotation ............... Counter-clockwise
Combustion Principle ............... Direct injection multi-hole nozzle configuration
Valve Drive Mechanism ............... Camshaft driven via tappets, push-rods, and rocker arms
Number of Valves per Cylinder ............... 2 (1 overhead intake valve, 1 overhead exhaust valve)
Crankcase Material ............... Light alloy die-cast aluminum
Cylinder Block Material ............... Grey cast iron
Cylinder Head Material ............... Light alloy aluminum
Lubrication System ............... Full-pressure lubrication with gear pump
Oil Pump Type ............... Gear-driven force-feed pump
Oil Filtration Type ............... Full-flow spin-on cartridge type or optional internal screen
Cooling System ............... Forced air cooling via flywheel blower fan
Cooling Fan Type ............... Axial flywheel integrated fan blower
Air Cleaner Type ............... Dry type multi-stage dual element or optional oil-bath filter
Decompression Mechanism ............... Manual lever config with automatic-return option
Emissions Certification ............... EPA Tier 4 Final and EU Stage V compliant
Starting System ............... Electric starter motor with optional manual crankhandle start
Electrical System ............... 12V or 24V
Alternator Output 12V, A ............... 14
Alternator Output 24V, A ............... 7

Fuel System

Fuel Injection Method ............... Direct Injection high-pressure system
Injection Pump Model Type ............... Bosch PFR single plunger block pump configuration
Injection Pump Drive ............... Internal engine camshaft lobe driven
Fuel Injector Nozzle Type ............... Multi-hole micro-orifice nozzle
Fuel Injector Opening Pressure, psi (bar) ............... 3190-3480 (220-240)
Fuel Delivery Feed Pump Type ............... Mechanical diaphragm lift pump driven by camshaft
Fuel Feed Pump Maximum Pressure, psi (bar) ............... 4.35-7.25 (0.3-0.5)
Standard Integrated Fuel Tank Volume, gal (L) ............... 1.32-1.85 (5.0-7.0)
Fuel Specification Standard Compliance ............... EN 590, BS 2869 A1/A2, ASTM D 975
Governor System Type ............... Mechanical centrifugal governor
Fuel Filtration System ............... Spin-on cartridge element with water separator reservoir
Fuel Return Line Config ............... Low-pressure excess bleed return line directly to supply tank
Injection Timing Angle, degrees ............... 11.5-13.5 BTDC
Injection Line Wall Thickness, in (mm) ............... 0.078 (2.0)
Injection Line Outer Diameter, in (mm) ............... 0.236 (6.0)
Fuel Tank Cap Ventilation ............... Integrated positive pressure atmospheric vent valve
Maximum Fuel System Back-Pressure, psi (bar) ............... 1.45 (0.1)

Dimensions and Weight

Overall Length (Standard Crank Start), in (mm) ............... 15.6 (395)
Overall Length With Electric Starter, in (mm) ............... 17.5 (445)
Overall Width (Standard Configuration), in (mm) ............... 19.3 (490)
Overall Width With Control Capsule Enclosure, in (mm) ............... 21.4 (545)
Overall Height (Standard Configuration), in (mm) ............... 22.3 (565)
Overall Height With Control Capsule Enclosure, in (mm) ............... 24.0 (610)
Dry Weight (Basic Engine Configuration), lbs (kg) ............... 183 (83)
Dry Weight with Silent Pack Enclosure, lbs (kg) ............... 260 (118)

Maintenance Data

Service Information

Compression Pressure Range, psi (bar) ............... 435-507 (30.0-35.0)
Oil Pressure at 850 rpm, psi (bar) ............... 8.7 (0.6)
Oil Pressure at 3000 rpm, psi (bar) ............... 36.3 (2.5)
Maximum Air Operating Temperature, F (C) ............... 122 (50)
Minimum Cold Start Temperature, F (C) ............... 14 (-10)
Intake Valve Clearance (Cold), in (mm) ............... 0.0039 (0.10)
Exhaust Valve Clearance (Cold), in (mm) ............... 0.0078 (0.20)

Engine Oil

Engine Oil Type .................. SAE 10W-40, SAE 5W-30, or 15W-40
API Service Classifications ......................... CK-4, CJ-4, Cl-4
Engine Oil Capacity, Minimum Level Mark, qt (L) ............... 1.16 (1.1)
Engine Oil Capacity, Maximum Level Mark, qt (L) ............... 2.01 (1.9)

Service Intervals

Change engine oil ............... Every 250 hours
Replace oil filter ............... Every 250 hours
Replace air filter ............... Every 500 hours
Replace fuel filter ............... Every 500 hours
Valve clearance adjustment ............... Every 250 hours
Fuel system inspection ............... Every 500 hours
Clean cooling fin ............... Every 250 hours
Check battery ............... Every 250 hours
Inspect breather Valve ............... Every 1000 hours

Service Specifications

Cylinder Bore Inside Diameter, in (mm) ............... 3.8188-3.8196 (97.000-97.022)
Cylinder Bore Maximum Wear Limit, in (mm) ............... 3.8236 (97.120)
Cylinder Bore Maximum Out-of-Round, in (mm) ............... 0.0011 (0.030)
Connecting Rod Small End Bushing I.D, in (mm) ............... 1.1813-1.1816 (30.007-30.018)
Connecting Rod Big End Journal I.D, in (mm) ............... 2.3622-2.3628 (60.000-60.015)
Connecting Rod Bearing Clearance, in (mm) ............... 0.0014-0.0031 (0.036-0.080)
Connecting Rod Big End Side Clearance, in (mm) ............... 0.0039-0.0078 (0.100-0.200)
Crankshaft Main Journal Diameter, in (mm) ............... 2.3614-2.3622 (59.980-60.000)
Crankshaft Main Bearing Diameter, in (mm) ............... 2.3582 (59.900)
Crankshaft Main Bearing Clearance, in (mm) ............... 0.0015-0.0035 (0.040-0.090)
Crankpin Journal Diameter, in (mm) ............... 2.1645-2.1653 (54.980-55.000)
Crankpin Bearing Clearance, in (mm) ............... 0.0011-0.0031 (0.030-0.080)
Crankshaft End Play, in (mm) ............... 0.0020-0.0059 (0.050-0.150)
Piston Skirt Outer Diameter, in (mm) ............... 3.8153-3.8161 (96.910-96.930)
Piston to Cylinder Bore Clearance, in (mm) ............... 0.0027-0.0044 (0.070-0.112)
Piston Pin Bore Inside Diameter, in (mm) ............... 1.1812-1.1814 (30.003-30.008)
Piston Pin Outer Diameter, in (mm) ............... 1.1809-1.1811 (29.995-30.000)
Piston Pin to Piston Pin Bore Clearance, in (mm) ............... 0.0001-0.0005 (0.003-0.013)
Piston Pin to Small End Bushing Clearance, in (mm) ............... 0.0003-0.0011 (0.008-0.028)
Top Ring Groove Width, in (mm) ............... 0.0787-0.0795 (2.000-2.020)
Second Ring Groove Width, in (mm) ............... 0.0787-0.0795 (2.000-2.020)
Oil Ring Groove Width, in (mm) ............... 0.1574-0.1582 (4.000-4.020)
Top Ring End Gap, in (mm) ............... 0.0098-0.0157 (0.250-0.400)
Second Ring End Gap, in (mm) ............... 0.0098-0.0157 (0.250-0.400)
Oil Ring End Gap, in (mm) ............... 0.0098-0.0157 (0.250-0.400)
Top Ring Side Clearance, in (mm) ............... 0.0019-0.0035 (0.050-0.090)
Second Ring Side Clearance, in (mm) ............... 0.0015-0.0027 (0.040-0.070)
Oil Ring Side Clearance, in (mm) ............... 0.0011-0.0025 (0.030-0.065)
Cylinder Head Flatness Distortion, Maximum, in (mm) ............... 0.0019 (0.050)
Valve Guide Inside Diameter, in (mm) ............... 0.3153-0.3161 (8.010-8.030)
Intake Valve Stem Outer Diameter, in (mm) ............... 0.3137-0.3143 (7.968-7.982)
Exhaust Valve Stem Outer Diameter, in (mm) ............... 0.3129-0.3136 (7.950-7.965)
Intake Valve Stem to Guide Clearance, in (mm) ............... 0.0011-0.0024 (0.028-0.062)
Exhaust Valve Stem to Guide Clearance, in (mm) ............... 0.0017-0.0031 (0.045-0.080)
Intake Valve Head Thickness, in (mm) ............... 0.0472-0.0551 (1.200-1.400)
Exhaust Valve Head Thickness, in (mm) ............... 0.0433-0.0511 (1.100-1.300)
Valve Head Recession Depth, in (mm) ............... 0.0275-0.0433 (0.700-1.100)
Valve Seat Contact Width, in (mm) ............... 0.0590-0.0787 (1.500-2.000)
Valve Spring Free Length, in (mm) ............... 1.732 (44.00)
Camshaft Bearing Journal Diameter, in (mm) ............... 1.5740-1.5748 (39.980-40.000)
Camshaft Bearing Clearance, in (mm) ............... 0.0011-0.0027 (0.030-0.070)
Camshaft End Play, in (mm) ............... 0.0039-0.0118 (0.100-0.300)
Rocker Arm Shaft Outer Diameter, in (mm) ............... 0.5505-0.5511 (13.984-14.000)
Rocker Arm Bushing Inner Diameter, in (mm) ............... 0.5518-0.5524 (14.016-14.034)
Rocker Arm Bushing-to-Shaft Clearance, in (mm) ............... 0.0006-0.0019 (0.016-0.050)
Crankshaft Timing Gear Journal Diameter, in (mm) ............... 1.3775-1.3781 (34.989-35.000)
Camshaft Timing Gear Journal Diameter, in (mm) ............... 1.1807-1.1812 (29.990-30.002)

Tightening Torques

Cylinder Head Nut (1-Stage) ............... 22.1 lb-ft (30.0 Nm)
Cylinder Head Nut (2-Stage) ............... 55.3 lb-ft (75.0 Nm)
Connecting Rod Cap Bolt ............... 36.8 lb-ft (50.0 Nm)
Main Bearing Block Housing Fasteners ............... 36.8 lb-ft (50.0 Nm)
Flywheel Central Screw Base ............... 103.2 lb-ft (140.0 Nm)
Crankcase Breather Deck Plate Screws ............... 7.3 lb-ft (10.0 Nm)
Cylinder Head Cover Center Nut ............... 8.8 lb-ft (12.0 Nm)
Oil Sump Pan Flange Fasteners ............... 7.3 lb-ft (10.0 Nm)
Engine Oil Drain Plug ............... 36.8 lb-ft (50.0 Nm)
Oil Pressure Switch ............... 14.7 lb-ft (20.0 Nm)
Oil Pump Assembly Plate Screws ............... 7.3 lb-ft (10.0 Nm)
Injection Pump to Case Nuts ............... 20.6 lb-ft (28.0 Nm)
Fuel Injector Hold-Down Clamp Stud Nut ............... 25.8 lb-ft (35.0 Nm)
High-Pressure Fuel Injection Line Unions ............... 18.4 lb-ft (25.0 Nm)
Fuel Feed Pump Flange Mounting Screws ............... 11.0 lb-ft (15.0 Nm)
Timing Gear Cover Assembly Housing Bolts ............... 8.8 lb-ft (12.0 Nm)
Camshaft Axial Thrust Washer Screw ............... 7.3 lb-ft (10.0 Nm)
Rocker Arm Shaft Pillar Support Fastener ............... 18.4 lb-ft (25.0 Nm)
Exhaust Silencer Box Nut Flange ............... 20.6 lb-ft (28.0 Nm)
Air Filter Housing Support Bolts ............... 7.3 lb-ft (10.0 Nm)
Starter Motor Mounting Hex Bolt ............... 33.1 lb-ft (45.0 Nm)
Integrated Charging Stator Screws ............... 5.1 lb-ft (7.0 Nm)
Governor Control Lever Mechanism Locknut ............... 7.3 lb-ft (10.0 Nm)
Engine Mounting Bracket Outer Frame Fasteners ............... 55.3 lb-ft (75.0 Nm)
Speed Control Assembly Housing Screws ............... 4.7 lb-ft (6.5 Nm)
Decompression Control Housing Screws ............... 7.3 lb-ft (10.0 Nm)
Breather Valve Spring Deck Capscrew ............... 4.4 lb-ft (6.0 Nm)
Flywheel Cooling Fan Ring Attachment Fasteners ............... 7.3 lb-ft (10.0 Nm)
Fuel Tank Base Strap Retaining Nuts ............... 14.7 lb-ft (20.0 Nm)
Oil Pressure Relief Valve Hex Cap Nut ............... 29.5 lb-ft (40.0 Nm)
Crankcase Structural Tie-Rod Fastener ............... 22.1 lb-ft (30.0 Nm)
Valve Tappet Adjuster Screw Locknut ............... 8.8 lb-ft (12.0 Nm)
Intermediate Adaptor Housing Flange Bolts ............... 33.1 lb-ft (45.0 Nm)
Alternator Cable Junction Post Small Nut ............... 2.9 lb-ft (4.0 Nm)

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• Hatz Engines Specs
  
• Hatz 1D41 Specs
  
• Hatz 1D41S Specs
  
• Hatz 1D42 Specs
  
• Hatz 1D42S Specs
  
• Hatz 1D50 Specs
  
• Hatz 1D50Z Specs
  

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