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Hatz 1D41 Engine

The Hatz 1D41 is a professional-grade, air-cooled single-cylinder four-stroke diesel engine designed by Motorenfabrik Hatz. Built with a vertical cylinder orientation, this compact industrial engine is widely utilized in rugged applications such as small construction machinery, heavy-duty generators, and high-pressure pumps. Its design emphasizes longevity and a high power-to-weight ratio, featuring a die-cast light alloy crankcase paired with a resilient grey cast iron cylinder block for optimized structural rigidity.

The valve train utilizes an overhead valve configuration driven mechanically by the crankshaft. Valve actuation is controlled via a sequence consisting of the camshaft, drag levers/tappets, push-rods, and rocker arms. Manual adjustments to the valve clearance (tappet clearance) must be executed every 250 operational hours. Cylinder Bore: 90 mm. Piston Stroke: 65 mm. Total Displacement: 0.413 liters (413 cc).

Fuel System: Fuel Delivery relies on a highly efficient direct injection system. The injection system pressurizes the fuel and introduces it into the combustion chamber through a specialized multi-hole nozzle (multi-orifice nozzle). The setup is certified for operation with low-sulfur or ultra-low-sulfur diesel fuel complying with EN 590, BS 2869, or ASTM D 975 standards. Maintenance protocols mandate checking the fuel cartridge lines regularly and performing a fuel filter replacement every 500 hours, followed by injector tip cleaning every 1500 hours.

Engine lubrication is managed via a pressurized system driven by an integrated, gear-type oil pump. On specialized model variants, oil cleanliness is maintained through a full-flow oil filter. Thermal regulation is achieved exclusively through forced air cooling. The layout features a specialized flywheel fan that forces airflow directly across the external cooling fins of the cylinder head and cylinder block. Because the cooling fan and the charging alternator are integrated straight into the flywheel component, the design completely eliminates the need for external V-belts.

General Technical Data

Engine Specifications

Engine Model ............... Hatz 1D41
Engine Type ............... 4-stroke single-cylinder direct injection air-cooled diesel
Number of Cylinders ............... 1
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) ............... 4.4-8.6 (3.3-6.4)
Rated Engine Speed, rpm ............... 1500-3600
Peak Torque ............... 16.6 lb-ft (22.5 Nm) at 2500 rpm
Idle Speed ............... 800-950 rpm
Aspiration Type ............... Naturally Aspirated
Operating Speed ............... 3000 rpm
Compression Ratio ............... 21.0:1
Cylinder Block Type ............... Diecast light alloy crankcase with grey cast iron cylinder
Cylinder Head Type ............... Light alloy cast head
Rotation Direction ............... Anti-clockwise looking at the power take-off flywheel side
Crankcase Breather Type ............... Closed circuit diaphragm breather valve assembly
Lubrication System ............... Full-pressure lubrication with gear-driven pump
Oil Pump Type ............... Gear-driven force pump
Oil Filter Type ............... Full-flow mesh spin-on filter cartridge
Cooling System ............... Axial fan cooling flywheel combination forced air-cooling
Air Cleaner Type ............... Dry type air filter cartridge with optional service indicator
Emission Certification ............... EPA Tier 4 final and EU Stage V compliant
Starting System ............... Hand crank start with automatic decompression or electric starter
Electrical System ............... 12V or 24V DC
Alternator Capacity ............... 14A or 28A

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 before top dead center position profile
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 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) ............... 14.3 (365)
Overall Width, in (mm) ............... 18.2 (465)
Overall Height, in (mm) ............... 20.6 (520)
Dry Weight (Base Config), lbs (kg) ............... 157 (71)
Dry Weight (Electric Kit), lbs (kg) ............... 205 (93)

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)
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 (Maximum), qt (L) ............... 1.26 (1.2)
Engine Oil Capacity (Minimum), qt (L) ............... 0.84 (0.8)

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) ............... 3.543-3.544 (90.000-90.022)
Cylinder Bore Wear Limit, in (mm) ............... 3.548 (90.130)
Cylinder Bore Taper Maximum, in (mm) ............... 0.0007 (0.020)
Crankshaft Main Journal Diameter, in (mm) ............... 2.164-2.165 (54.980-55.000)
Crankpin Journal Diameter, in (mm) ............... 1.968-1.969 (49.980-50.000)
Crankshaft End Play in (mm) ............... 0.0039-0.0078 (0.100-0.200)
Connecting Rod Big End Bore I.D, in (mm) ............... 2.086-2.087 (53.000-53.018)
Connecting Rod Small End Bushing Bore I.D, in (mm) ............... 1.102-1.103 (28.000-28.007)
Connecting Rod Big End Side Play, in (mm) ............... 0.0039-0.0078 (0.100-0.200)
Connecting Rod Bearing Clearance, in (mm) ............... 0.0011-0.0027 (0.030-0.070)
Crankshaft Main Bearing Clearance, in (mm) ............... 0.0015-0.0031 (0.040-0.080)
Piston Skirt Ouside Diameter Metric, in (mm) ............... 3.539-3.540 (89.910-89.930)
Piston to Cylinder Wall Clearance, in (mm) ............... 0.0035-0.0044 (0.090-0.112
Piston Pin Outer Diameter, in (mm) ............... 1.099-1.100 (27.994-28.000)
Piston Pin to Small End Bushing Clearance, in (mm) ............... 0.0002-0.0005 (0.006-0.013)
Piston Pin Bore Inside Diameter, in (mm) ............... 1.100-1.101 (28.003-28.012)
Piston Pin to Piston Pin Bore Clearance, in (mm) ............... 0.0001-0.0007 (0.003-0.018)
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) ............... 0.0098-0.0177 (0.250-0.450)
Top Ring Groove Side Clearance, in (mm) ............... 0.0023-0.0035 (0.060-0.090)
Second Ring Groove Side Clearance, in (mm) ............... 0.0015-0.0027 (0.040-0.070)
Oil Ring Groove SideClearance, in (mm) ............... 0.0011-0.0023 (0.030-0.060)
Cylinder Head Flatness Distortion, in (mm) ............... 0.0019 (0.050)
Intake Valve Stem Outer Diameter, in (mm) ............... 0.313-0.314 (7.965-7.980)
Exhaust Valve Stem Outer Diameter, in (mm) ............... 0.312-0.313 (7.945-7.960)
Valve Guide Inside Diameter, in (mm) ............... 0.315-0.316 (8.000-8.015)
Intake Valve Stem to Guide Clearance, in (mm) ............... 0.0007-0.0019 (0.020-0.050)
Exhaust Valve Stem to Guide Clearance, in (mm) ............... 0.0015-0.0027 (0.040-0.070)
Intake Valve Seat Angle ............... 45 deg
Exhaust Valve Seat Angle ............... 45 deg
Intake Valve Head Recession Depth, in (mm) ............... 0.027-0.043 (0.700-1.100)
Exhaust Valve Head Recession Depth, in (mm) ............... 0.027-0.043 (0.700-1.100)
Valve Spring Free Length, in (mm) ............... 1.692 (43.000)
Camshaft Journal Diameter, in (mm) ............... 1.651-1.652 (41.960-41.980)
Camshaft End Play, in (mm) ............... 0.0039-0.0118 (0.100-0.300)
Cam Lobe Height (Intake), in (mm) ............... 1.417-1.421 (36.000-36.100)
Cam Lobe Height (Exhaust), in (mm) ............... 1.417-1.421 (36.000-36.100)
Camshaft Radial Journal Clearance, in (mm) ............... 0.0007-0.0027 (0.020-0.070)
Rocker Arm Bushing Inside Diameter, in (mm) ............... 0.708-0.709 (18.000-18.018)
Rocker Arm Shaft Outside Diameter, in (mm) ............... 0.707-0.708 (17.966-17.984)
Rocker Arm Shaft to Bushing Clearance, in (mm) ............... 0.0006-0.0020 (0.016-0.052)
Tappet Lifter Body Outside Diameter, in (mm) ............... 0.786-0.787 (19.970-19.990)
Tappet Guide Bore Inside Diameter, in (mm) ............... 0.787-0.788 (20.000-20.021)
Tappet Body to Guide Bore Clearance, in (mm) ............... 0.0003-0.0020 (0.010-0.051)

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 ............... 258.1-280.2 lb-ft (350.0-380.0 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 1D41S Specs
  
• Hatz 1D42 Specs
  
• Hatz 1D42S Specs
  
• Hatz 1D50 Specs
  
• Hatz 1D50S Specs
  
• Hatz 1D50Z Specs
  

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