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6CT8.3-GM129 Auxiliary Engine

DCEC 6CT8.3-GM129 marine auxiliary engine is a 6-cylinders in line, 8.3 liters four-strokes engine with 114mm bore and 135mm stroke.

Equipped with BYC PB fuel pump and GAC electronic governor, engine comes with turbocharger.

The prime power for generator set 1800RPM of DCEC 6CT8.3-GM129 marine auxiliary engine is 129kW.

DCEC provides both heat exchanger cooling and radiator cooling marine auxiliary engines, which mainly using for marine main generator and marine emergency generator.

For the emergency generator set applications, we provide additional options for customers such as dual starter motor system (we provide both electric and spring starter motor for customers), which are required by most of international classifications.

All of DCEC marine auxiliary engine are comes with dry type exhaust system, which means dry type exhaust manifold and dry type turbocharger, SeaMac provides upgrading services for water-cooled exhaust system, which modify dry type exhaust system into water-cooled exhaust system, which are quite important and often requested by passenger boat projects.

Advantages of 6CT8.3-GM129 Auxiliary Engine

  • Advanced design, exquisite manufacturing technology, reliable and durable, suitable for high-strength and heavy-duty operations under severe working conditions.

  • Using high-pressure fuel pump, combustion is more complete under high fuel injection pressure, less energy loss, strong power, strong fuel adaptability, and lower emissions.

  • Adopt Holset supercharger with integral wastegate valve, low speed responsiveness and strong power.

  • Integral cylinder design, the number of parts is about 25% less than similar products, the failure rate is lower, and the maintenance is more convenient.

  • The cylinder liner adopts a platform mesh honing design and a corrosion-resistant high-nickel cast iron piston, which greatly reduces oil loss, enhances durability, and has a longer service life.

Technical Specifications

Engine Model:6CT8.3-GM129
Engine Type:6 Cylinders
Displacement:8.3 L
Rated Speed:1800 RPM
Rated Power / Speed:129 kW @ 1800 RPM
Peak Torque:222 g / kW.h @ 1800 RPM
Aspiration Method:Turbocharged
Emission Standard:N / A
Bore*Storke:114 mm * 135 mm
Packing Size(L*W*H):1494 mm * 796 mm * 1228 mm
Wet Weight:637 kg
Lead Time:15-30 Working Days
Payment Terms:T/T ,L/C

Coming Soon

Engine Model

Peak Torque

Rated Power

Fuel System


6CT8.3-GM115212 g / kW.h @ 1500 RPM115 kW @ 1500 RPMBYC PB Pump / GAC Electronic GovernorTurbocharged
6CT8.3-GM129222 g / kW.h @ 1800 RPM129 kW @ 1800 RPM  BYC PB Pump / GAC 24 V Electronic GovernorTurbocharged
6CTA8.3-GM155214 g / kW.h @ 1500 RPM155 kW @ 1500 RPMBYC PB Pump / GAC Electronic GovernorTurbocharged & Water-Air Intercooler
6CTA8.3-GM175218 g / kW.h @ 1800 RPM175 kW @ 1800 RPMBYC P7100 Pump / GAC 24 V Electronic GovernorTurbocharged & Water-Air Intercooler

General Infomation of DCEC 6CT8.3-GM129 Marine Auxiliary Engine

Engine Model6CT8.3 – GM129Displacement8.3 L
Bore * Stroke114 mm * 135 mmAspirationTurbocharged
Cylinders6 Cylinders, in LineFuel SystemBYC PB Pump / GAC 24 V Electronic Governor
Governor Regulation 5 %Rated Power129 kW @ 1800 RPM
Standby Power142 kW @ 1800 RPMDry Weight637 kg
Instantaneous Inertia of Rotating Parts0.37 kg·m²Low Idle Speed950 – 1050 RPM
Distance from Center of Gravity to Center Line of Crankshaft (Above Crankshaft)
163 mm
Distance Between Center of Gravity and Rear End Face of Cylinder Block541 mm
Compression Ratio17.3 : 1Piston Speed8.1 m / sec
Firing Order1 – 5 – 3 – 6 – 2 – 4

Installation Data of DCEC 6CT8.3-GM129 Marine Auxiliary Engine

Maximum (Static) Bending Moment at Front Support Mounting Surface495 N.m
Maximum (Static) Bending Moment Allowed for Side-mounted BossN / A
Maximum (Static) Bending Moment at Rear Face of Block1356 N.m
Moment of Inertia of Complete Engine – Roll Axis23.6 kg.m²
Moment of Inertia of Complete Engine – Pitch Axis65.2 kg.m²
Moment of Inertia of Complete Engine – Yaw Axis55.9 kg.m²

Fuel System of DCEC 6CT8.3-GM129 Marine Auxiliary Engine

Maximum Fuel Flow of Oil Pump202 litre / hr
Maximum Oil Intake Resistance – Clean Fuel Filter63.5 mmHg
Maximum Oil Intake Resistance – Dirty Fuel Filter100 mmHg
Maximum Fuel Inlet Temperature60 ℃
Maximum Allowable Return Line Pressure254 mmHg

DCEC 6CT8.3-GM129 Marine Auxiliary Engine

System Technical Data of DCEC 6CT8.3-GM129 Marine Auxiliary Engine

Exhaust SystemMaximum Exhaust Back Pressure75 mmHg
Exhaust Gas FlowN / A
Exhaust Gas Temperature515
Exhaust Heat Loss WorkN / A
Recommended Exhaust Pipe Diameter75 mm
Maximum Static Support Weight of Turbocharger Outlet Flange22.7 kg
Air Intake SystemMaximum Intake Air Restriction with Heavy Duty Air Cleaner—Clean Element380 mmH2O
Maximum Intake Air Restriction with Heavy Duty Air Cleaner—Dirty Element635 mmH2O
Minimum Dirt Holding Capacity with Heavy Duty Air Cleaner53 g / litre / sec
Maximum Temperature Rise from Ambient to the Inlet of the Turbocharger17
Maximum Pressure Drop from Turbocharger Outlet to Intake Manifold75 mmHg
Intake Air Flow180 litre / sec
Heat Rejection to Ambient30 kW
Minimum Ambient Temperature for Cold Starting-12
LubricationSystemNormal Operating Oil Pressure Range276 – 414 kPa
Maximum Lube Oil Flow for Engine Accessories7.6 litre / min
Maximum Sump Oil Temperature121
Minimum Oil Pressure—At Low Idle103 kPa
Minimum Oil Pressure – Operating Speed276 kPa
Minimum Required Lube System Capacity – Sump Plus Filters19 litre
By-Pass Filtration RequiredYes
Sump Inclination Angle—Front Up45 °
Sump Inclination Angle—Front Down45 °
Sump Inclination Angle—Side to Side45 °
Cool Start SystemMinimum Recommended Battery Capacity12 V 24 V
– 18 Completely Cold, only the Engine Cold Starting Current1500 CCA * 750 CCA
Engine Only – Reserve Capacity360 – 180 minutes
Maximum Voltage Drop of Starting LoopN / A
Minimum Ambient Temperature without Auxiliary Cold Start-12
Minimum Starting Speed Required without Auxiliary Cold Starting120 RPM
Maximum Allowable Resistance of Starting Loop0.0012 * 0.002 Ohms
Cooling SystemCoolant Capacity – Engine Only10 litre
Minimum Water Inlet Pressure of the Pump (without Pressure Cover, Thermostat Open)N / A
Maximum Static Height of Coolant above Crankshaft Centerline of EngineN / A
Thermostat Standard Regulating Temperature (Range)82 – 95
Maximum Cylinder Block Coolant Pressure (without Pressure Cap, Thermostat Closed)103 kPa
Minimum Pressure Cap Pressure69 kPa
Maximum Engine Coolant Temperature100
Minimum Coolant Temperature79.4
Minimum Coolant Expansion Volume Relative to System Capacity5 %
Heat Rejection to Coolant73 kW
Engine Coolant Flow – 1psi Engine External Cooling Cycle Resistance240 litre / min
5psi Engine External Cooling Cycle Resistance210 litre / min
Maximum External Engine Cooling Cycle Resistance35 kPa
Sea Water Pump Flow (10 psi Sea Water Pump End Pressure Drop)170 litre / min
Aximum Beaeration Time25 min
Minimum Coolant Water Loss Volume Relative to Total System Capacity0.11 %
Outlet Temperature of Coolant When the Clutch Fan is Running93

Scopes of Supply of DCEC 6CT8.3-GM129 Marine Auxiliary Engine

Air Intake System1. Air Intake ManifoldExhuast System1. Exhuast Manifold
2. Air Filter2. Turbocharger
3. N / A3. Exhuast Elbow
Starting System1. Starter MotorCharging System1. Charging Alternator
2. Starter Rely2. N / A
Lubricating System1. Oil PumpFuel System1. Fuel Transfer Pump
2. Oil Filter2. High-Pressure Fuel Pump
3. N / A3. Machanical Governor
4. N / A4. Fuel Filter
Engine Shut-Down System1. Engine Fuel Shut-Off SolenoidPower Output System1. Flywheel
2. N / A2. Standard Flywheel Housing

Optional Accessories of DCEC 6CT8.3-GM129 Marine Auxiliary Engine

Air Intake System1. Air Intake Pre-HeaterExhuast System1. Muffler & Bellows
2. Air Intake Pre-Filter2. Flame Trap
3. Air Filter Alarm System3. Spark Arrestor Type Muffler & Bellows
4. N / A4. DPF System
Fuel System1. Coarse FilterEngine Auiliary Accessories1. Hydraulic Oil Pump
2. Fuel Pre-Heater2. Hydraulic Cluch
Starting System1. Manual Magnetic DC ContactorCooling System1. Engine Monitor
2. Dual Ears Flywheel Housing2. Engine Protection System With Alarm System
3. Spring Starter Motor3. Machanical Engine Control Lever Syste
4. Air Starter Motor4. Electric Engine Control Lever System
5. Hydraulic Starter Motor5. N / A
6. Manual Magnetic DC Contactor6. N / A
Power Output System1. Gear Reduction GearboxCooling System1. Coolant Pre-Heater
2. Reverse Gear Box2. Jacket Water Heater
Lubricating System1. Oil Pre-HeaterEngine Mounting System1. Shock Absorber Pad


Committed to providing reliable premium propulsion system and power system for all kinds of ships around the world, SeaMac is a sub-brand of EMAC group that focused on maritime application.
SeaMac’s ranges of products mainly inclduing marine main engine, marine gearbox, marine propellers, marine control lever system, marine auxiliary engine, marine generator set and emergency generator set.
For more information of our marine proplusion and power system products, you are welcome to visit SeaMac homepage:

Modifiable components of DCEC 6CT8.3-GM129 Marine Auxiliary  Engine

Air Intake System1. Installation Position of Air FilterStarting System1. 12V Starter Motor for 12V Electric System
2. Upgrade to Heavy-Duty Type Air Fitler2. Upgrading to Specified Brand and Speicifications of Starter Motor
Exhuast System1. Can Modify Installation Position and Direction of TurbochargerCharging System1. 12V Charging Alternator for 12V Electric System
2. Water-Cooled Exhuast Manifold2. Explosion-Proof Charging Alternator
3. Water-Cooled Turbocharger3. Upgrading to Specified Brand and Speicifications of Charging Alternator
Fuel System1. Upgrade to Fuel Fitler That Integrated with Fuel Transfer Pump and Fuel Pre-HearterEngine Auiliary Accessories1. Additional Auxiliary Systems Can Be Added for Special Applications
Engine Shut-Down System1. 12V Solenoid for 12V Electric SystemCooling System1. Can Modify Engine Into Keel Cooling System
2. Explosion-Proof Solenoid2. N / A
Lubricating System1. Oil Pan PositionPower Output System1. Can Modify Size of Flywheel Housing and Flywheel
2. Number of Dipstick2. Dual-Ear Flywheel Housing (For Twin-Starter System)
3. Position of Dipstick Can Choose from 6 Positions3. Some of Models Can Modify Flywheel Housing Into PTO Integrated Type
4. Can Modify Oil Filter to Be Remote Installation4. Engine Have Connecting Port of PTOs, That Able to Provide Power Output
Engine Mounting System1. Can Modify Engine Mouting Bracket

Note: All Above Data are Just for Reference, All Data Might Change Without Notices or Updates, Please Contact Our Sales Team to Confirm All Details Via WhatsApp or Email.

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