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Cat® 3056 Diesel Marine Propulsion Engines, with ratings of 127-208 mhp (125-205 bhp) at 2100-2600 rpm, meet IMO I and EU RDC emission standards. The 3056 engine is one of the most compact packages in its class with outstanding reliability and durability. This versatile, powerful engine can be applied in single or twin engine work boat, fish boat, passenger ferry, patrol craft, or pleasure craft applications. The excellent fuel consumption and 400-hour oil change interval are significant factors in the overall low operating cost.

Power Rating

Power Range 125 - 205 bhp (93 - 153 bkW) 125 - 205 bhp (93 - 153 bkW) Less
Maximum Continuous Ratings - Maximum Power 205.0 bhp 208.0 bkW Less

Engine Specifications

Speed Range 2100 - 2600 rpm 2100 - 2600 rpm Less
Emissions IMO I, EU RCD IMO I, EU RCD Less
Aspiration NA, TA NA, TA Less
Bore 3.94 in 100.0 mm Less
Stroke 5.0 in 127.0 mm Less
Displacement 365.0 in3 6.0 L Less
Rotation (from flywheel end) Counterclockwise Counterclockwise Less
Configuration In-line 6, 4-Stroke-Cycle Diesel In-line 6, 4-Stroke-Cycle Diesel Less

Dimensions & Weights

Minimum Dry Weight 1312.0 lb 595.0 kg Less
Minimum Length 42.05 in 1068.0 mm Less
Maximum Length 42.05 in 1068.0 mm Less
Minimum Height 31.5 in 801.0 mm Less
Maximum Height 31.5 in 801.0 mm Less
Minimum Width 25.4 in 645.0 mm Less
Maximum Width 30.6 in 779.0 mm Less

IMO Emissions Compliant

DITA engine complies to current regulations with the capability of meeting proposed future legislation.

High Quality Reliable Product

The 3056 is approved by major marine classification societies, and is designed to provide years of dependable service.

Low Operating Costs

Excellent fuel economy and the 400-hour oil change interval make the 3056 very economical to operate.

Environmentally Friendly

The cold start timing advance mechanism reduces white smoke at start-up. The controlled expansion piston and low friction ring pack are designed to control oil consumption. These features directly contribute to easier cold starting and lower emissions at idle and operating speeds.

Flexible Installation

The 3056 design allows multiple installation angle capability for a variety of vessels from +17° to -5° (requires optional Engine Front Down Kit), with a maximum 30° vessel operating angle. Multi-groove crankshaft pulley has two available grooves for PTO drives which adds to the compactness of engine. Multi-option exhaust outlets provide the most suitable cost-effective design for each installation including repowers. The height of the mounting feet can be adjusted to make installation easy.

Cost Effective Core Engines

The high volume production provides more cost effective core engines with reduced delivery time.

Specialized High Quality Marinization

Complete propulsion packages are designed to meet customer requirements.

Powerful and Efficient

The direct injection combustion system with rotary fuel pump and two valves per cylinder improves combustion efficiency and provides more power and torque with lower fuel consumption, thus reducing operating costs. The lightweight component design of the composite expansion tank and air filter intake improves engine power-to-weight ratio and is more cost effective.

Outstanding Performance

The wastegated turbocharger on the 205 hp engine develops more horsepower at lower engine speeds for more vessel acceleration. The dry insulation on the turbocharger improves engine performance and is more cost effective. The insulation lowers the surface temperature of the turbocharger and improves safety.

Reliable and Durable Component Design

The positive drive gear-driven jacket water and sea water pump provide greater reliability and lower operating costs. The helically cut gear train contributes to the acoustically tuned mechanical structure of the engine to provide lower engine noise and quieter overall operation. The plate-type oil cooler has no water pipes or connections and is less likely to develop leaks. The replaceable valve seat inserts and guides extend service life for long term reliability and delay major component replacement. Watercooled exhaust manifolds reduce the possibility of corrosion and fire. The fuel shutoff solenoid (ETS) with manual override lever is built into the fuel pump with no external linkage for safe reliable operation at no extra cost. Insulated electrical components reduce fire hazards and corrosion with no sacrificial anodes required. The sea water strainer protects the aftercooler from debris and potential overheating and improves reliability.

3056 Standard Equipment

Air Inlet System
  • Air Cleaner/Fumes Disposal (closed system)
  • Aftercooler (sea water) (DITA)
  • Dry Insulated Turbocharger (DITA)
  • Thermostart Air Inlet Heater

Control System
  • Mechanical Governor

Exhaust System
  • Dry Insulated Turbocharger (DITA)
  • Water Cooled Exhaust Manifold

Fuel System
  • Twin Fuel Filter

Lube System
  • Crankcase Breather (closed system)
  • Twin Oil Filter
  • Engine Mounted Oil Sump Drain Pump
  • RH Service Oil Level Gauge

Power Takeoffs
  • Hydraulic pump drive, SAE A, 11 tooth spline, 46 ft-lb max torque, conterclockwise as viewed from front of the engine looking into the drive and turns 1.41 x engine speed, 292 mm crankshaft pulley, 15.88 mm width

  • Vibration Damper
  • Vibration Damper Plastic Wrap Packaging
  • Lifting Eyes
  • English Literature

Flywheel and Flywheel Housing
  • SAE No. 3 flywheel
  • SAE No. 3 flywheel housing

Cooling System
  • Gear Driven Centrifugal Jacket Water Pump
  • Gear Driven Self-priming Sea Water Pump (DITA and DINA Heat Exchanger arrangements and DITA Keel Cooled arrangements)
  • Heat Exchanger with Cupro-Nickel Tube Bundle (Heat Exchanger cooled arrangements)
  • De-aeration Expansion Tank
  • Keel Cooling Connections (Keel cooled arrangements)
  • Integral Plate-Type Engine Oil Cooler
  • Sea Water Strainer (DITA)
  • Transmission Oil Cooler (DINA)
  • Thermostat and Housing
  • NOTE: Engines for keel cooling do not include keel cooler

3056 Optional Equipment

Cooling System
  • Engine Front Down Kit

Fuel System
  • Flexible Fuel Lines
  • Water Separator/Flex Fuel Lines
  • Double Wall Fuel Lines and Drain

Mounting System
  • Flexible Mounts

Marine Transmissions & Attachments
  • Marine Transmission Output Couplings
  • Flexible Coupling
  • Solid Half Coupling
  • Flexible with Mating Solid Half Coupling

  • Cruise Kits


Special Tests
  • Standard Engine Test - 3000 Family

  • Storage Preservation
  • Export Packing - Individual Engine Shipments
  • Export Packing - 20' Container Shipments
  • Export Packing - 40' Container Shipments

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