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Volvo Penta D6-400 Engine

The Volvo Penta D6-400 is an in-line 6-cylinder marine diesel engine engineered for high-performance applications, typically utilizing a Duoprop drive (DP) system. Manufactured with a heavy-duty cast-iron cylinder block and a fully cast cylinder head, the structural integrity is reinforced by a specialized ladder frame fitted to the base of the engine block. This design significantly minimizes operation-induced vibrations and noise levels. It integrates an advanced Electronic Vessel Control (EVC) system to manage engine diagnostics and optimize combustion parameters, making it highly suitable for fast commercial workboats, patrol craft, and high-speed leisure vessels requiring heavy marine torque and low emissions.

The engine utilizes a 4-valve-per-cylinder technology operating via double overhead camshafts (DOHC). The valvetrain features integrated hydraulic lash adjusters to eliminate manual adjustments and replaceable valve seats to ensure long-term durability under heavy thermal loads. The engine develops a maximum power output of 400 hp (294 kW). The total displacement of the straight-six configuration is 5.5 liters (336 cubic inches). Bore and stroke geometry is optimized to maintain high mechanical efficiency, transferring power via a rigid seven-bearing crankshaft and a rear-end transmission layout.

Fuel System: Fuel delivery is managed via a high-pressure common-rail direct fuel injection system. An integrated electronic control unit processes precise multi-stage injection timing to eliminate traditional diesel knock and lower emissions. The fuel delivery line is completed by a dedicated fine filter assembly featuring an integrated water separator to prevent water contamination within the high-pressure fuel rail.

Lubrication System: The forced lubrication network relies on oil-cooled pistons equipped with two compression rings and one oil scraper ring. The system filters oil through an easily replaceable dual assembly containing a separate full-flow filter and a bypass oil filter. Thermal regulation of the lubricant is managed by a dedicated seawater-cooled tubular oil cooler.

Cooling System: The engine utilizes a split-circuit heat exchanger cooling configuration. The internal primary circuit circulates freshwater through the engine block, cylinder head, and turbocharger housing. The secondary circuit utilizes external seawater to cool the charge-air cooler, the tubular engine oil cooler, and the primary freshwater heat exchanger before discharging through the exhaust elbow or exhaust riser.

General Technical Data

Engine Specifications

Engine Model ............... Volvo Penta D6-400 A
Engine Type ............... 4-stroke inline 6-cylinder direct injection liquid-cooled marine diesel
Number of Cylinders ............... 6
Cylinder Arrangement ............... In-line
Engine Bore, in (mm) ............... 4.05 (103.0)
Engine Stroke, in (mm) ............... 4.33 (110.0)
Displacement, cu.in (L) ............... 335.6 (5.50)
Rated Engine Power, hp (kW) ............... 400 (294)
Rated Engine Speed, rpm ............... 3500
Crankshaft Peak Torque, lb-ft (Nm) ............... 723 (980) at 2000 rpm
Low Idle Speed, rpm ............... 600-650
Aspiration Type ............... Turbocharger, mechanical supercharger, charge air cooler
Maximum Operating Speed, rpm ............... 3500
Compression Ratio ............... 17.5:1
Firing Order ............... 1-5-3-6-2-4
Cylinder Block Type ............... Heavy-duty cast iron with ladder frame assembly
Cylinder Head Type ............... Monoblock cast iron 4-valve per cylinder assembly
Valves Per Cylinder ............... 4
Camshaft Design ............... Double overhead camshafts DOHC
Valve Train Operation ............... Hydraulic lash adjusters with roller finger followers
Main Bearings Configuration ............... 7-bearing crankshaft assembly
Lubrication System ............... Full-pressure circulation with dedicated oil cooling jets
Oil Pump Type ............... Gear-driven displacement pump
Oil Filter Type ............... Dual full-flow spin-on filters with single bypass filter
Cooling System ............... Thermostatically regulated closed freshwater system with open seawater loop
Seawater Pump Type ............... Gear-driven positive displacement centrifugal rubber impeller pump
Emission Certification ............... US EPA Tier 3, IMO NOx, EU RCD Stage II standards
Air Cleaner Type ............... Multi-stage cleanable cartridge system with internal silencer
Starting System ............... Electric starter motor assembly
Electrical System Voltage ............... 12V or 24V secondary configurations
Alternator Capacity ............... 115A with built-in electronic charge regulator

Fuel System

Injection Architecture ............... High-pressure electronically controlled common rail design
High Pressure Fuel Pump ............... Bosch CP3.3 generation radial plunger pump assembly
System Fuel Rail Pressure, psi (bar) ............... 5801 to 29007 (400 to 2000)
Minimum Cranking Rail Pressure, psi (bar) ............... 2900 (200)
Fuel Injection Control ............... Electronic Diesel Control EDC7 engine management platform
Pressure Regulation Mechanism ............... Magnetic proportional valve MPROP fuel metering unit
Fuel Injector Type ............... Multi-hole electro-hydraulic solenoid command injectors
Fuel Feed Supply Pump ............... Mechanical gear-driven transfer pump built into high pressure housing
Primary Filtration Stage ............... Water-separating pre-filter with water-in-fuel sensor alarm
Secondary Filtration Stage ............... High-efficiency spin-on fine particulate fuel filter element
Fuel Cooling System ............... Tubular sea-water cooled fuel return heat exchanger unit
Maximum Fuel Inlet Restriction, in Hg (kPa) ............... 4.0 (13.5)
Maximum Fuel Return Line Backpressure, in Hg (kPa) ............... 5.9 (20.0)

Dimensions and Weight

Overall Engine Length, in (mm) ............... 53.7 (1365)
Overall Engine Width, in (mm) ............... 32.2 (820)
Overall Engine Height, in (mm) ............... 35.8 (910)
Dry Weight with HS85AE Transmission, lbs (kg) ............... 1499 (680)
Dry Weight with Aquamatic Drive, lbs (kg) ............... 1742 (790)
Operating Weight with Inboard setup, lbs (kg) ............... 1576 (715)
Operating Weight with Stern Drive, lbs (kg) ............... 1818 (825)

Maintenance Data

Service Information

Oil Pressure at Normal Idle, psi (kPa) ............... 18.1 (125)
Oil Pressure at 3500 rpm, psi (kPa) ............... 63.8 (440)
Oil Pressure at Low Idle, psi (kPa) ............... 11.6 (80)
Oil Pressure Relief Valve, psi (kPa) ............... 101.5 (700)
Cooling System Cap Pressure Rating, psi (kPa) ............... 10.9 (75)
Maximum Engine Oil Temperature, F (C) ............... 257 (125)
Thermostat Start To Open Temperature, F (C) ............... 180 (82)
Thermostat Fully Open Temperature, F (C) ............... 198 (92)

Engine Oil and Coolant

Engine Oil Type .................. SAE 5W-30, SAE 10W-30, or SAE 15W-40
API Service Classifications ......................... CH-4 or CI-4
Engine Oil Capacity with Filters, US qt (L) ............... 21.1 (20.0)
Engine Oil Capacity (Low Level), US qt (L) ............... 16.9 (16.0)
Coolant Capacity Closed Circuit, US gal (L) ............... 4.2 (16.0)
Compressor Oil Capacity, US qt (L) ............... 0.11 (0.1)
HS80AE Reverse Gear Oil Capacity, US qt (L) ............... 5.8 (5.5)
HS80IVE V-Drive Oil Capacity, US qt (L) ............... 7.4 (7.0)
DPH Duoprop Drive Oil Capacity, US qt (L) ............... 5.5 (5.2)

Service Intervals

Change oil and filter ............... Every 200 hours
Service air cleaner ............... Every 100 hours
Replace air cleaner ............... Every 400 hours
Replace fuel filter ............... Every 200 hours
Fuel system inspection ............... Every 1200 hours
Change coolant ............... Every 1000 hours
Compression test ............... Every 2000 hours
Replace drive belt ............... Every 400 hours
Replace impeller ............... Every 200 hours
Service heat exchanger ............... Every 400 hours

Service Specifications

Cylinder Bore Inner Diameter, in (mm) ............... 4.0551-4.0559 (103.000-103.020)
Cylinder Bore Maximum Wear Limit, in (mm) ............... 4.0591 (103.100)
Cylinder Bore Ovality Maximum, in (mm) ............... 0.0008 (0.020)
Cylinder Bore Taper Maximum, in (mm) ............... 0.0008 (0.020)
Main Bearing Journal Diameter, in (mm) ............... 3.3461-3.3468 (84.992-85.012)
Main Bearing Clearance, in (mm) ............... 0.0015-0.0035 (0.040-0.090)
Connecting Rod Bearing Journal Diameter, in (mm) ............... 2.5587-2.5594 (64.992-65.010)
Connecting Rod Bearing Clearance, in (mm) ............... 0.0015-0.0033 (0.038-0.084)
Crankshaft Axial End Play, in (mm) ............... 0.0031-0.0118 (0.080-0.300)
Thrust Bearing Journal Width, in (mm) ............... 1.4567-1.4583 (37.000-37.040)
Connecting Rod Total Side Play, in (mm) ............... 0.0059-0.0138 (0.150-0.350)
Piston Skirt Outside Diameter, in (mm) ............... 4.0511-4.0523 (102.900-102.930)
Piston to Cylinder Bore Clearance, in (mm) ............... 0.0027-0.0047 (0.070-0.120)
Piston Pin Diameter, in (mm) ............... 1.5746-1.5748 (39.994-40.000)
Piston Pin to Con Rod Bushing Clearance, in (mm) ............... 0.0006-0.0014 (0.015-0.035)
Top Ring Groove Side Clearance, in (mm) ............... 0.0024-0.0043 (0.060-0.110)
Second Ring Groove Side Clearance, in (mm) ............... 0.0019-0.0037 (0.050-0.095)
Oil Ring Groove Side Clearance, in (mm) ............... 0.0011-0.0029 (0.030-0.075)
Top Ring End Gap, in (mm) ............... 0.0118-0.0197 (0.300-0.500)
Second Ring End Gap, in (mm) ............... 0.0197-0.0295 (0.500-0.750)
Oil Ring End Gap, in (mm) ............... 0.0098-0.0197 (0.250-0.500)
Cylinder Head Flatness Distortion, in (mm) ............... 0.0039 (0.10)
Cylinder Block Deck Flatness, in (mm) ............... 0.0020 (0.05)
Intake Valve Stem Outside Diameter, in (mm) ............... 0.2736-0.2742 (6.950-6.965)
Exhaust Valve Stem Outside Diameter, in (mm) ............... 0.2724-0.2732 (6.920-6.940)
Intake Valve Guide Inside Diameter, in (mm) ............... 0.2756-0.2764 (7.000-7.020)
Exhaust Valve Guide Inside Diameter, in (mm) ............... 0.2756-0.2764 (7.000-7.020)
Intake Valve Stem to Guide Clearance, in (mm) ............... 0.0014-0.0027 (0.035-0.070)
Exhaust Valve Stem to Guide Clearance, in (mm) ............... 0.0024-0.0039 (0.060-0.100)
Intake Valve Head Depth, in (mm) ............... 0.0276-0.0394 (0.700-1.000)
Exhaust Valve Head Depth, in (mm) ............... 0.0276-0.0394 (0.700-1.000)
Valve Seat Angle ............... 45 degrees
Valve Face Angle ............... 44.5 degrees
Camshaft Journal Diameter, in (mm) ............... 1.9681-1.9693 (49.990-50.020)
Camshaft Bearing Clearance, in (mm) ............... 0.0019-0.0039 (0.050-0.100)
Cam Lobe Height (Intake), in (mm) ............... 0.3346 (8.50)
Cam Lobe Height (Exhaust), in (mm) ............... 0.3543 (9.00)
Camshaft Axial End Play, in (mm) ............... 0.0039-0.0098 (0.100-0.250)

Tightening Torques

Cylinder Head Bolts (1-Stage), lb-ft (Nm) ............... 36.9 (50.0)
Cylinder Head Bolts (2-Stage), lb-ft (Nm) ............... 73.8 (100.0)
Cylinder Head Bolts (3-Stage), lb-ft (Nm) ............... 110.6 (150.0)
Main Bearing Cap Bolts (1-Stage), lb-ft (Nm) ............... 44.3 (60.0)
Main Bearing Cap Bolts (2-Stage), lb-ft (Nm) ............... 95.9 (130.0)
Connecting Rod Cap Bolts (1-Stage), lb-ft (Nm) ............... 22.1 (30.0)
Connecting Rod Cap Bolts (2-Stage), lb-ft (Nm) ............... 47.9 (65.0)
Flywheel Fixing Bolts (1-Stage), lb-ft (Nm) ............... 36.9 (50.0)
Flywheel Fixing Bolts (2-Stage), lb-ft (Nm) ............... 73.8 (100.0)
Vibration Damper Crankshaft Pulley Bolts, lb-ft (Nm) ............... 62.7 (85.0)
Camshaft Gear Center Retaining Bolt, lb-ft (Nm) ............... 55.3 (75.0)
Camshaft Bearing Cap, lb-ft (Nm) ............... 17.7 (24.0)
Crankcase Oil Pan Mounting Bolts, lb-ft (Nm) ............... 17.7 (24.0)
Oil Pan Drain Plug, lb-ft (Nm) ............... 33.2 (45.0)
Valve Rocker Arm Shaft Support Bolts, lb-ft (Nm) ............... 22.1 (30.0)
Engine Valve Cover Top Screws, lb-ft (Nm) ............... 8.1 (11.0)
Exhaust Manifold Flange Nuts, lb-ft (Nm) ............... 35.4 (48.0)
Turbocharger Mounting Flange Nut, lb-ft (Nm) ............... 35.4 (48.0)
Common Rail High Pressure Fuel Line Nuts, lb-ft (Nm) ............... 20.7 (28.0)
Fuel Injector Clamping Bracket Fasteners, lb-ft (Nm) ............... 15.5 (21.0)
High Pressure Fuel Pump Drive Gear Bolt, lb-ft (Nm) ............... 66.4 (90.0)
Fuel Injector Feed Pipe Connection Joints, lb-ft (Nm) ............... 19.9 (27.0)
Alternator Bracket Base Pivot Bolts, lb-ft (Nm) ............... 35.4 (48.0)
Starter Motor Frame Mounting Fasteners, lb-ft (Nm) ............... 35.4 (48.0)
Seawater Pump Housing Screws, lb-ft (Nm) ............... 15.5 (21.0)
Oil Cooler Housing Core Clamping Screws, lb-ft (Nm) ............... 17.7 (24.0)
Freshwater Thermostat Housing Cover Bolts, lb-ft (Nm) ............... 17.7 (24.0)
Flywheel Housing to Engine Block (M12), lb-ft (Nm) ............... 62.7 (85.0)
Flywheel Housing to Engine Block (M10), lb-ft (Nm) ............... 35.4 (48.0)
Crankcase Breather Element Cover Screws, lb-ft (Nm) ............... 8.1 (11.0)
Supercharger Compressor Sump Drain Plug, lb-ft (Nm) ............... 14.8 (20.0)
Supercharger Assembly Main Bracket Bolts, lb-ft (Nm) ............... 35.4 (48.0)
Intake Manifold Air Inlet Plenum Bolts, lb-ft (Nm) ............... 17.7 (24.0)
Glow Plug Cylindrical Heating Elements, lb-ft (Nm) ............... 11.1 (15.0)
Oil Pump Internal Delivery Pipe Flange, lb-ft (Nm) ............... 8.1 (11.0)
Piston Oil Cooling Jet Nozzle Bolt, lb-ft (Nm) ............... 11.1 (15.0)
Timing Gear Case Backplate M8 Bolts, lb-ft (Nm) ............... 17.7 (24.0)
Timing Gear Case Outer Cover M6 Screws, lb-ft (Nm) ............... 7.4 (10.0)
Engine Oil Filter Bypass Valve Assembly, lb-ft (Nm) ............... 25.8 (35.0)
Coolant Heat Exchanger Drain Cock Valve, lb-ft (Nm) ............... 18.4 (25.0)
Raw Water Sacrificial Anode Brass Plug, lb-ft (Nm) ............... 22.1 (30.0)
Engine Support Foot Marine Mount Bolts, lb-ft (Nm) ............... 103.3 (140.0)
Exhaust Riser Discharge Elbow Band Clamp, lb-ft (Nm) ............... 8.9 (12.0)
Engine Control Unit Heat Sink Bolts, lb-ft (Nm) ............... 6.6 (9.0)
Rail Pressure Sensor Threaded Interface, lb-ft (Nm) ............... 51.6 (70.0)
Fuel Temperature Sensor Brass Housing, lb-ft (Nm) ............... 14.8 (20.0)
Coolant Temperature Sensor Element, lb-ft (Nm) ............... 16.2 (22.0)
Manifold Boost Air Pressure Sensor Bolt, lb-ft (Nm) ............... 6.6 (9.0)
Lube Oil Pressure Sensor, lb-ft (Nm) ............... 22.1 (30.0)
Crankshaft Position Sensor Pickup Bracket, lb-ft (Nm) ............... 7.4 (10.0)
Camshaft Position Reference Indicator Bolt, lb-ft (Nm) ............... 7.4 (10.0)
Water In Fuel Contamination Bottom Sensor, lb-ft (Nm) ............... 2.2 (3.0)
Sea Water Circuit Impeller End Cover Screws, lb-ft (Nm) ............... 4.4 (6.0)
Air Intake Silencer Filter Housing Clamps, lb-ft (Nm) ............... 5.2 (7.0)
Compressor Drive Electromagnetic Clutch Bolt, lb-ft (Nm) ............... 44.3 (60.0)

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• Volvo Penta Engines Specs
  
• Volvo Penta D6-310 Specs
  
• Volvo Penta D6-350 Specs
  
• Volvo Penta D6-370 Specs
  
• Volvo Penta D6-380 Specs
  
• Volvo Penta D6-440 Specs
  
• Volvo Penta D6-480 Specs
  

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