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Hatz 1D41S Engine

The Hatz 1D41S is a commercial-grade, single-cylinder, vertical four-stroke diesel engine featuring direct fuel injection. The "S" designation specifies a standard layout arrangement built for versatility in industrial, mobile, and agricultural machinery. Highly regarded for its rugged modularity and mechanical integrity, the engine incorporates an open-access crankcase architecture designed for ease of field servicing. The power unit utilizes a heavy flywheel mass to offset primary imbalances inherent to single-cylinder designs, providing excellent torque delivery under varying load profiles.

The cylinder head houses an overhead valve (OHV) arrangement operated via mechanical lifters, solid pushrods, and rocker arms driven directly by the camshaft. Power Range: 2.5-6.4 kW (equivalent to 3.4-8.6 hp). Bore: 90 mm. Stroke: 65 mm. Total Displacement: 413 cc (0.413 liters). Compression Ratio: 21.0:1.

Fuel System: Fuel delivery utilizes a direct-injection combustion strategy engineered for high thermal efficiency. The assembly encompasses a gravity or low-pressure mechanical feed circuit pulling from the storage tank through an inline fuel filter element into a dedicated high-pressure mechanical injection pump module. This injection pump feeds a finely calibrated high-pressure fuel line running to a multi-hole direct fuel injector nozzle array centered in the cylinder head. Excess fuel bypasses back through dedicated return lines to maintain system priming and cooling.

The engine uses a pressurized lubrication circuit supplied by a positive-displacement gear-type oil pump. Minimum Oil Pressure: 0.6 bar at a low idle threshold of 850 rpm, measured at an operational oil temperature ceiling of 100C. Engine thermal regulation relies entirely on a direct, forced air-cooling mechanism. A cooling air fan integrated directly into the engine's main flywheel assembly forces high-velocity airflow over the extended cooling fins of both the cylinder block and cylinder head. Air guidance is maintained by structural metal cowlings and air duct channeling plates.

General Technical Data

Engine Specifications

Engine Model ............... Hatz 1D41S
Engine Type ............... 4-stroke single-cylinder direct-injection air-cooled diesel engine
Number of Cylinders ............... 1
Cylinder Arrangement ............... Vertical upright inline single cylinder configuration
Engine Bore, in (mm) ............... 3.54 (90.0)
Engine Stroke, in (mm) ............... 2.56 (65.0)
Displacement, cu.in (L) ............... 25.2 (0.413)
Rated Engine Power, hp (kW) ............... 3.4-8.6 (2.5-6.4)
Rated Engine Speed, rpm ............... 1500-3600
Peak Torque, lb-ft (Nm) ............... 16.2-18.4 (22.0-25.0) at 2000-2500 rpm
Idle Speed Minimum, rpm ............... 850-950
Aspiration Type ............... Naturally aspirated atmospheric intake air suction system
Operating Speed Range, rpm ............... 1500-3600
Compression Ratio ............... 20.0:1
Combustion System ............... Open chamber direct fuel injection system
Valves Per Cylinder ............... 2
Valve Mechanism ............... Overhead valve operated by pushrods lifters and rocker arms
Direction of Rotation ............... Counter-clockwise looking directly at the flywheel face
Cylinder Block Material ............... High strength pressure die-cast light metal alloy crankcase
Cylinder Head Design ............... Heavy duty light alloy cylinder head with cooling fins
Lubrication System ............... Full circulation pressure lubrication driven via internal pump
Oil Pump Type ............... Positive displacement gear type forced lubrication delivery pump
Oil Filter Type ............... Full-flow screen mesh filtration with optional spin-on canister filter
Cooling System ............... Direct air cooling layout utilizing an integrated flywheel blower fan
Air Blower Design ............... Integrated flywheel cooling fan forcing airflow over cylinder fins
Air Cleaner Assembly ............... Dry type element with optional integrated heavy duty oil bath
Starting System ............... Hand crank mechanism with kick-back damping or electric starter
Electrical System ............... Flywheel integrated permanent magnet generator charging unit
System Voltage, V ............... 12 or 24

Fuel System

Injection Pump Type ............... Single plunger block high-pressure pump system unit
Injection Pump Drive ............... Camshaft lobe operated mechanical lifter linkage assembly
Injection Nozzle Type ............... Multi-hole micro orifice direct injection nozzle body assembly
Injection Pressure, psi (bar) ............... 3625-3915 (250-270)
Governor Type ............... Centrifugal mechanical governor with variable speed configuration
Fuel Injection Timing ............... 14-18 deg BTDC
Fuel Delivery Pump ............... Mechanical diaphragm lift pump driven by camshaft accentrics
Fuel Feed Line Diameter, in (mm) ............... 0.236 (6.0)
Fuel High Pressure Line, in (mm) ............... 0.078 (2.0)
Fuel Feed Line Maximum Pressure, psi (bar) ............... 7.2-10.1 (0.5-0.7)
Fuel Filter Type ............... High efficiency spin-on element cartridge water separator unit combo
Fuel Tank Capacity, gal (L) ............... 1.32 (5.0)
Fuel Specifications ............... EN 590 ultra low sulfur diesel or ASTM D 975 std grade oil fuel
Injection Plunger Diameter, in (mm) ............... 0.275 (7.0)
Injection Plunger Stroke, in (mm) ............... 0.236 (6.0)
Nozzle Opening Pressure New, psi (bar) ............... 3915 (270)
Nozzle Opening Pressure Used, psi (bar) ............... 3625 (250)
Maximum Allowable Suction Head, in (mm) ............... 19.6 (500)

Dimensions and Weight

Overall Length, in (mm) ............... 15.3 (390)
Overall Width, in (mm) ............... 18.7 (475)
Overall Height, in (mm) ............... 21.1 (535)
Dry Weight, lbs (kg) ............... 172 (78)
Operating Weight, lbs (kg) ............... 190 (86)

Maintenance Data

Service Information

Compression Pressure Test, psi (bar) ............... 406-464 (28.0-32.0)
Oil Pressure at Low Idle, psi (bar) ............... 8.7 (0.6)
Oil Pressure at Rated Speed, psi (bar) ............... 36.2-58.0 (2.5-4.0)
Maximum Oil Temperature, Limit, F (C) ............... 248.0 (120.0)
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 5W-30, SAE 10W-30, or 15W-40
API Service Classifications ......................... CK-4, CJ-4
Engine Oil Capacity without Filter, qt (L) ............... 1.16 (1.1)
Engine Oil Capacity with Filter, qt (L) ............... 1.26 (1.2)

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 crankcase valve ............... Every 1000 hours

Service Specifications

Cylinder Bore Inside Diameter, in (mm) ............... 3.5433-3.5441 (90.000-90.022)
Cylinder Bore Max Wear Limit, in (mm) ............... 3.5484 (90.130)
Cylinder Bore Max Out of Round, in (mm) ............... 0.0011 (0.030)
Crankshaft Main Journal Outside Diameter, in (mm) ............... 1.9681-1.9687 (49.990-50.005)
Main Bearing Journal Inside Diameter, in (mm) ............... 1.9700-1.9712 (50.040-50.070)
Crankshaft Main Bearing Clearance, in (mm) ............... 0.0013-0.0031 (0.035-0.080)
Crankpin Journal Outside Diameter, in (mm) ............... 1.7712-1.7718 (44.990-45.005)
Connecting Rod Big End Inside Diameter, in (mm) ............... 1.7732-1.7744 (45.040-45.070)
Connecting Rod Big End Bearings Clearance, in (mm) ............... 0.0013-0.0031 (0.035-0.080)
Crankshaft Axial End Play, in (mm) ............... 0.0039-0.0078 (0.100-0.200)
Piston Skirt Outer Diameter, in (mm) ............... 3.5397-3.5405 (89.910-89.930)
Piston To Cylinder Bore Clearance, in (mm) ............... 0.0027-0.0043 (0.070-0.110)
Piston Pin Outside Diameter, in (mm) ............... 1.1021-1.1023 (27.994-28.000)
Piston Pin Bore Inside Diameter, in (mm) ............... 1.1031-1.1039 (28.020-28.040)
Piston Pin to Small End Bushing Clearance, in (mm) ............... 0.0007-0.0017 (0.020-0.046)
Piston Pin Bushing Outer Diameter, in (mm) ............... 1.1822-1.1831 (30.030-30.050)
Top Ring Groove Width, in (mm) ............... 0.0996-0.1003 (2.530-2.550)
Second Ring Groove Width, in (mm) ............... 0.0807-0.0814 (2.050-2.070)
Oil Ring Groove Width, in (mm) ............... 0.1586-0.1594 (4.030-4.050)
Top Ring Side Clearance, in (mm) ............... 0.0023-0.0037 (0.060-0.095)
Second Ring Side Clearance, in (mm) ............... 0.0015-0.0029 (0.040-0.075)
Oil Ring Side Clearance, in (mm) ............... 0.0011-0.0025 (0.030-0.065)
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)
Cylinder Head Deck Bottom Surface Flatness, in (mm) ............... 0.0019 (0.050)
Intake Valve Head Diameter, in (mm) ............... 1.41 (36.0)
Exhaust Valve Head Diameter, in (mm) ............... 1.22 (31.0)
Intake Valve Stem To Guide Clearance, in (mm) ............... 0.0011-0.0023 (0.030-0.060)
Exhaust Valve Stem To Guide Clearance, in (mm) ............... 0.0019-0.0031 (0.050-0.080)
Valve Guide Inside Diameter, in (mm) ............... 0.2759-0.2767 (7.010-7.030)
Intake Valve Seat Contact Width, in (mm) ............... 0.059-0.078 (1.500-2.000)
Exhaust Valve Seat Contact Width, in (mm) ............... 0.078-0.098 (2.000-2.500)
Valve Head Recession, in (mm) ............... 0.031-0.043 (0.800-1.100)
Valve Spring Free Length, in (mm) ............... 1.57 (40.0)
Camshaft Journal Outside Diameter, in (mm) ............... 1.1807-1.1812 (29.990-30.005)
Camshaft Bushing Inside Diameter, in (mm) ............... 1.1822-1.1834 (30.030-30.060)
Camshaft Journal to Bushing Clearance, in (mm) ............... 0.0010-0.0027 (0.025-0.070)
Rocker Arm Shaft Outside Diameter, in (mm) ............... 0.4721-0.4724 (11.990-12.000)
Rocker Arm Bushing Inside Diameter, in (mm) ............... 0.4732-0.4744 (12.020-12.050)
Rocker Arm Bushing To Shaft Clearance, in (mm) ............... 0.0007-0.0023 (0.020-0.060)

Tightening Torques

Cylinder Head Nuts (First Stage) ............... 11.0 lb-ft (15.0 Nm)
Cylinder Head Nuts (Second Stage) ............... 22.1 lb-ft (30.0 Nm)
Cylinder Head Nuts (Final Stage) ............... 36.8-40.5 lb-ft (50.0-55.0 Nm)
Connecting Rod Cap Bolts (First Stage) ............... 14.7 lb-ft (20.0 Nm)
Connecting Rod Cap Bolts (Final Stage) ............... 28.0-30.9 lb-ft (38.0-42.0 Nm)
Flywheel Central Locknut ............... 132.7-147.5 lb-ft (180.0-200.0 Nm)
Crankshaft Main Bearing Bolts ............... 33.1-36.8 lb-ft (45.0-50.0 Nm)
Counterweight Mass Retaining Capscrews ............... 16.9-19.1 lb-ft (23.0-26.0 Nm)
Crankcase Breather Valve Cover Small Screws ............... 2.9-4.4 lb-ft (4.0-6.0 Nm)
Timing Gear Cover Outer Capscrews ............... 6.6-8.1 lb-ft (9.0-11.0 Nm)
Oil Pump Housing Assembly Plate Screws ............... 6.6-8.1 lb-ft (9.0-11.0 Nm)
Oil Drain Plug ............... 36.8 lb-ft (50.0 Nm)
Injection Pump Block Anchor Flange Nuts ............... 16.9-19.1 lb-ft (23.0-26.0 Nm)
Injector Clamping Bracket Hold Down Stud Nut ............... 19.1-21.3 lb-ft (26.0-29.0 Nm)
High Pressure Pipe Union Compression Delivery Nuts ............... 18.4-22.1 lb-ft (25.0-30.0 Nm)
Diaphragm Lift Feed Pump Flange Base Nuts ............... 14.7-16.9 lb-ft (20.0-23.0 Nm)
Rocker Arm Shaft Support Pillar Anchor Bolt ............... 16.9-19.1 lb-ft (23.0-26.0 Nm)
Valve Clearance Tappet Adjuster Screw ............... 6.6-8.1 lb-ft (9.0-11.0 Nm)
Valve Cover VCentral Cushion Compression Nut ............... 7.3-8.8 lb-ft (10.0-12.0 Nm)
Air Cleaner Housing Carrier Mounting Support Screws ............... 16.9-19.1 lb-ft (23.0-26.0 Nm)
Exhaust Manifold Flange Steel Clamping Nuts ............... 18.4-20.6 lb-ft (25.0-28.0 Nm)
Electric Starter Unit Flange Case Mount Screws ............... 33.1-36.8 lb-ft (45.0-50.0 Nm)
Alternator Stator Bracket Arm Pivot Tensioner Bolt ............... 16.9-19.1 lb-ft (23.0-26.0 Nm)
Oil Pressure Sensor Indicator Switch ............... 11.0-13.2 lb-ft (15.0-18.0 Nm)
Governor Speed Control Lever Friction Disc Pivot Nut ............... 8.8-11.0 lb-ft (12.0-15.0 Nm)
Flywheel Fan Outer Sheet Metal Cowling Screws ............... 5.8-7.3 lb-ft (8.0-10.0 Nm)
Crankcase Breathing Chamber Separator Deflector Screws ............... 2.2-3.6 lb-ft (3.0-5.0 Nm)
Automatic Decompression Mechanism Shaft Stop Bolt ............... 22.1-25.8 lb-ft (30.0-35.0 Nm)
Stubshaft Extension PTO Output Hub Adapter Bolts ............... 16.9-19.1 lb-ft (23.0-26.0 Nm)
Fuel Tank Drain Plug Cap ............... 22.1-25.8 lb-ft (30.0-35.0 Nm)
Speed Control Cover Plate Front Flange Screws ............... 6.6-8.1 lb-ft (9.0-11.0 Nm)
Fuel Return Overflow Spill Pipe Tee Hollow Banjo Bolt ............... 8.8-10.3 lb-ft (12.0-14.0 Nm)
Fuel Feed Supply Line Diaphragm Union Banjo Bolt ............... 12.5-14.7 lb-ft (17.0-20.0 Nm)
Camshaft Thrust Flange Ring Crankcase Countersunk Screws ............... 6.6-7.3 lb-ft (9.0-10.0 Nm)
Oil Galley End Core Sealing Expansion Hex Plug ............... 29.5-33.1 lb-ft (40.0-45.0 Nm)
Crankcase Split Line Case Half Outer Frame Bolts ............... 16.9-19.1 lb-ft (23.0-26.0 Nm)
Governor Flyweight Cage Assembly Locknut ............... 25.8-29.5 lb-ft (35.0-40.0 Nm)
Injection Pump Lifter Guide Roller Bushing Screws ............... 4.4-5.8 lb-ft (6.0-8.0 Nm)
Intake Manifold Tube To Cylinder Head Nuts ............... 14.7-16.9 lb-ft (20.0-23.0 Nm)

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• Hatz Engines Specs
  
• Hatz 1D41 Specs
  
• Hatz 1D42 Specs
  
• Hatz 1D42S Specs
  
• Hatz 1D50 Specs
  
• Hatz 1D50S Specs
  
• Hatz 1D50Z Specs
  

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