New | 3512B Commercial Marine Propulsion Engine

The Cat 3512B marine engine includes the Advanced Diesel Engine Management System II, Control Monitoring Protection System, Customer Communication Module, and Digital Voltage Regulator. Benefits include improved fuel economy, reduced visible and gaseous emissions, enhanced diagnostic and monitoring capabilities, and increased rated output with no reduction in reliability.

Power Rating
Power Range1100-2250 bhp (820-1678 bkW)
Engine Specifications
Speed Range1200-1925 rpm
ConfigurationVee 12, 4-Stroke-Cycle Diesel
Bore6.7 in
Stroke7.5 in
Displacement3158.0 in3
Rotation (from flywheel end)Counterclockwise or Clockwise
EmissionsIMO I
Dimensions & Weights
Minimum Length111 in
Maximum Length3067 in
Minimum Width67.1 in
Maximum Width70.2 in
Minimum Height71.1 in
Maximum Height82.3 in
Maximum Dry Weight14411 lb
Minimum Dry Weight14411 lb
  • Electronic Unit Injector Fuel System Featuring 10-20 Percent Higher Injection Pressure Than Other 3500 Family Engines
  • Caterpillar Adem Ii Electronic Engine Control/monitoring System That Provides Infinitely Variable Injection Timing And A State-of-the-art Monitoring And Protection System With Self-diagnosing Electronic Sensors
  • “deep Crater/low Crevice Volume” Twopiece Articulated Piston Design With Forged Steel Crown And Cast Aluminum Skirt That Enhance Combustion Efficiency To Provide Improved Fuel Efficiency And Lower Levels Of Gaseous And Visible Emissions
  • Larger Diameter (98 Mm Vs. 92 Mm Bore) Camshaft For Higher Injection Pressures, Shorter Injection Durations, And Less Gear Train Torsional Vibration
  • Strengthened Fuel Injection Actuation System And Rear Gear Train To Maintain Reliability And Durability While Providing Higher Injection Pressures
  • Center-mounted Low Inertia Turbochargers (four On 3512b And 3516b; Two On 3508b) On Epg Models
  • Dual Rear Mounted Turbochargers On All Marine Configurations
  • Separate Circuit Or Sea Water Aftercooling To Supply The Optimum Temperature Air To The Combustion Chamber To Reduce Emissions And Fuel Consumption And Maximize Power Output
  • Streamlined Intake And Exhaust Manifolds To Reduce Parasitic Pumping Losses And Increase Combustion Efficiency
  • Thermo-laminated Heat Shields On All Marine Configurations To Maintain Surface Temperatures Below Marine Classification Society Regulations And To Retain More Exhaust Gas Energy For Increased Turbocharger Performance
  • Electronic Instrument Panel With Eight Analog Gauges, 10 Leds, And One Lcd Read-out To Display Engine Operating Conditions And Fault Codes
  • Pin-type Connector For Easy Connection Of Caterpillar Engine Technician Electronic Service Tool Which Delivers Superior Diagnostic Capability To Determine Exact Causes Of Engine Faults
  • Formed Elastomeric Seals Replace Gaskets On Rocker Arm Bases Eliminating Gasket Relaxation To Maintain Consistent Dimensions For Valve Lash And Injection Settings And Nuisance-type Oil Leaks.
  • Redesigned Aftercooler-to-intake Manifold Joints That Use Formed Elastomeric Seals And Substantially Fewer Fasteners To Give Superior Sealing Characteristics And Easier Serviceability

Standard Equipment

Air Inlet System
  • regular duty air cleaners, dual turbochargers, 152 mm (6 in) OD straight connection, corrosion resistant coated separate circuit aftercooler core
Control System
  • dual Advanced Diesel Engine Management (ADEM II) modules with electronically controlled unit injectors
Exhaust System
  • dry gas-tight exhaust manifolds with thermolaminated heat shields, dual turbochargers with watercooled bearings and thermo-laminated heat shields, vertical exhaust outlet, 203 mm (8 in) ID round flanged outlet
Fuel System
  • electronically controlled unit injectors, RH fuel filter with service indicators, fuel transfer pump
  • RH electronic instrument panel with analog gauges and digital display of data for: oil and fuel pressure, oil and fuel filter differential, system DC voltage, exhaust and water temperature, air inlet restriction; digital display only for: tachometer, service meter, fuel consumption (total and instantaneous); start/stop switch
Lube System
  • top mounted crankcase breather, deep sump oil pan, RH oil filler and dipstick, RH oil filter, gear type oil pump
Mounting System
  • ledge type engine length rails, 203 x 203 mm (8 x 8 in)
Power Takeoffs
  • accessory drive on standard rotation engines: lower RH, lower LH; on opposite rotation engines: upper and lower RH and upper and lower LH; twosided front housing
Protection System
  • ADEM II Electronic Monitoring System with customer programmable alarm, shutdown, and deration strategies; emergency stop pushbutton
  • front and rear lifting eyes, Caterpillar yellow paint, vibration damper and guard
Flywheel and Flywheel Housing
  • SAE No. 00 flywheel (183 teeth) and SAE No. 00 flywheel housing
Cooling System
  • auxiliary fresh water pump on SCAC engines, non-self-priming centrifugal auxiliary sea water pump for heat exchanger engines only, expansion tank, gear-driven centrifugal jacket water pump, oil cooler, keel cooling connections for keel cooled engines, thermostats and housing with 92° C (198° F) full open temperature

Optional Equipment

  • Air Cleaner Removal
  • Remote Air Inlet Adapters
  • Battery Chargers
  • Charging Alternators
  • Throttle Position Sensor
  • Throttle synchronization
  • Water level switch gauge
  • Coolant level sensors
  • Connections
  • Keel cooling conversions
  • Heat exchangers
  • Auxiliary water pumps
  • Sea water pump removal
  • Coolant shunt tanks
  • Air separator
  • Marine gear cooling
  • Horizontal Exhaust Outlet
  • Flexible fittings
  • Elbows
  • Flanges
  • Flange and exhaust expanders
  • Mufflers
  • Fuel Cooler
  • Fuel priming pumps
  • Flexible fuel lines
  • Rigid Fuel Lines
  • Primary fuel filter
  • Fuel level switch
  • PL1000T Communication Module
  • PL1000E Communication Module
  • Customer Interface Box
  • Thermocouples
  • Remote panel display
  • Remote cylinder temperature display
  • Pilot house instrument panels
  • Marine gear sensors
  • Engine vision display system
  • Oil Pan
  • Oil Pan Accessories
  • Sump Pumps
  • Prelubrication Options
  • Lubricating Oil
  • Lube System
  • Engine supports
  • Vibration Isolation Mountings
  • Flexible coupling and guards
  • Upper left hand front location:
  • Upper right hand front location:
  • Upper right hand rear location:
  • Lower left hand front location:
  • Lower left hand rear location:
  • Front housing accessory drives
  • Front power take offs
  • Crankshaft pulleys
  • Damper guard removals
  • Air inlet shutoffs
  • Switches and contactors
  • Explosion relief valve
  • Sensors
  • Chrome Plated Relief Valves
  • Black Air Cleaners
  • Starting motors or barring device
  • Air starting motor options:
  • Starting aids
  • Battery sets - 24 volt - Dry
  • Battery rack
  • Tool set
  • Caterpillar Datalink wire



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