C6.6 ACERT™ Standard Equipment

Air Inlet System

  • Turbocharged
  • Air-to-Air Aftercooled

Control System

  • Electronic governing, PTO speed control
  • Programmable ratings
  • Automatic altitude compensation
  • Power compensation for fuel temperature
  • Programmable low and high idle and total engine limit
  • Electronic diagnostics and fault logging
  • Engine monitoring system SAE J1939 broadcast and control
  • ADEM™ A4 Electronic Control Unit (ECU)

Cooling System

  • Thermostats and housing, vertical outlet
  • Jacket water pump, centrifugal
  • Water pump, inlet

Exhaust System

  • Exhaust manifold, dry
  • Optional exhaust outlet

Flywheels and Flywheel Housing

  • Choice of SAE No. 2 or SAE No. 3 flywheel housing

Fuel System

  • Electronic high pressure common rail
  • Fuel filter, secondary (2 micron)
  • ACERT™ Technology
  • Fuel transfer pump
  • Fuel priming pump

Lube System

  • Crankcase breather
  • Oil cooler
  • Oil filler
  • Lube oil filter
  • Front sump oil pan
  • Oil dipstick
  • Gear driven oil pump


  • Vibration damper
  • Lifting eyes
  • Cold start capability to -20° C (-4° F)
  • Paint: Caterpillar yellow, with optional colors available at request

Select Units


Cat® C6.6 ACERT Industrial Diesel Engines offer the perfect balance of durability, fuel efficiency and low emissions. Extensively tested on the job, these engines use a range of Common Rail fuel systems and advanced control systems to deliver maximum uptime in the harshest environment. They have proven they can handle the toughest applications and deliver superior performance that exceeds the expectations of the most demanding users. Industries and applications powered by C6.6 ACERT engines include: Agriculture, Ag Tractors, Aircraft Ground Support, Bore/Drill Rigs, Chippers/Grinders, Combines/Harvesters, Compactors/Rollers, Compressors, Construction, Cranes, Crushers, Feller Bunchers, Forestry, Forklifts, General Industrial, Harvesters, Hydraulic Power Units, Irrigation Equipment, Loaders/Forwarders, Material Handling, Mining, Mobile Earthmoving Equipment, Mobile Sweepers, Paving Equipment, Pumps, Skidders, Specialty Ag Equipment, Sprayers, Trenchers and Underground Mining Equipment. C6.6 ACERT engines, with ratings: 89-205 bkW (119-275 bhp) @ 2200-2500 rpm, meet U.S. EPA Tier 3 equivalent, EU Stage IIIA equivalent emission standards. They are available using U.S. EPA and EU Flexibility, and for other regulated and non-regulated areas.

Power Rating

  • Minimum Power 119.0 BHP 89.0 bkW
  • Maximum Power 275.0 BHP 205.0 bkW
  • Rated Speed 2200-2500 rpm 2200-2500 rpm

Emission Standards

  • Emissions U.S. EPA Tier 3 Equivalent, EU Stage IIIA Equivalent U.S. EPA Tier 3 Equivalent, EU Stage IIIA Equivalent


  • Engine Configuration Inline 6, 4-Stroke-Cycle Diesel Inline 6, 4-Stroke-Cycle Diesel
  • Bore 105 mm (4.13 in) 105 mm (4.13 in)
  • Stroke 127 mm (5.0 in) 127 mm (5.0 in)
  • Aspiration Turbocharged Aftercooled (TA) Turbocharged Aftercooled (TA)
  • Displacement 6.6 L (402.8 in³) 6.6 L (402.8 in³)
  • Compression Ratio 16.2:1 16.2:1
  • Combustion System Direct Injection Direct Injection
  • Rotation from Flywheel End Counterclockwise Counterclockwise

Engine Dimensions - Approximate

  • Height 797 mm (31.4 in) 797 mm (31.4 in)
  • Length 929 mm (36.6 in) 929 mm (36.6 in)
  • Weight - Net Dry - Basic Operating Engine Without Optional Attachments 506 kg (1116 lb) 506 kg (1116 lb)
  • Width 668 mm (26.3 in) 668 mm (26.3 in)


Meets U.S. EPA Tier 3 equivalent, EU Stage IIIA equivalent emission standards. Available using U.S. EPA Flexibility or EU Flexibility, and for other regulated and non-regulated areas.


Every Cat engine is manufactured to stringent quality standards in order to assure customer satisfaction.

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