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G3612 Standard Equipment

Air Inlet System
  • Air cleaner — standard dutyInlet air adapter

Control System
  • A3 control system — provides electronic governing integrated with air/fuel ratio control and individual cylinder ignition timing control

Cooling System
  • Jacket water pump
  • Jacket water thermostats and housing
  • Aftercooler pump
  • Aftercooler water thermostats and housing
  • Single-stage aftercooler

Exhaust System
  • Dry wrapped exhaust manifolds
  • Vertical outlet adapter

Flywheel & Flywheel Housing
  • SAE standard rotation

Fuel System
  • Gas admission valves — electronically controlled fuel supply pressure

Ignition System
  • A3 control system — senses individual cylinder detonation and controls individual cylinder timing

  • LCD display panel — monitors engine parameters and displays diagnostic codes

Lube System
  • Crankcase breathers — top mounted
  • Oil cooler
  • Oil filter
  • Oil pan drain valve

Mounting System
  • Engine mounting feet (six total)

Protection System
  • Electronic shutoff system with purge cycle
  • Crankcase explosion relief valves
  • Gas shutoff valve

Starting System
  • Air starting system

  • Paint — Cat yellow
  • Vibration dampers

G3612 Optional Equipment

Air Inlet System
  • Heavy-duty air cleaner with precleaners
  • Heavy-duty air cleaner with rain protection

Charging System
  • Charging alternators

Control System
  • Custom control system software — available for nonstandard ratings, field programmable using flash memory

Cooling System
  • Expansion tank
  • Flexible connections
  • Jacket water heater

Exhaust System
  • Flexible bellows adapters
  • Exhaust expander
  • Weld flanges

Fuel System
  • Fuel filter
  • Gas pressure regulator
  • Flexible connection
  • Low energy fuel system
  • Corrosive gas fuel system

Ignition System
  • CSA certification

  • Remote data monitoring and speed control
  • Compatible with Cat Electronic Technician (ET) and Data View
  • Communication Device — PL1000T/E
  • Display panel deletion is optional

Lube System
  • Air or electric motor-driven prelube
  • Duplex oil filter
  • LH or RH service
  • Lube oil makeup system

Mounting System
  • Mounting plates (set of six)

Power Take-Offs
  • Front stub shafts

Starting System
  • Air pressure reducing valve
  • Natural gas starting system

  • Engine barring device
  • Damper guard


G3600 engines provide a wide range of power options to fit your gas compression application. G3600 engines bring the highest uptime in the industry and long operating intervals between overhaul. Operators that use G3600 engines in their fleet enjoy virtually no unscheduled downtime, the right power for their application, the lowest operating costs, and emissions compliance.Ideal applications for G3600 engines include centralized gathering stations, gas processing, transmissions, and storage applications. Cat G3612 gas engine with ratings: 1647-2822 bkW (3550-3785 bhp) @ 1000 rpm. NSPS site compliant capable.

Engine Specifications

Minimum Rating 3550.0 BHP 2647.0 bkW Less
Maximum Rating 3785.0 BHP 2822.0 bkW Less
Emissions NSPS Site Compliant Capable NSPS Site Compliant Capable Less
Displacement 15528.0 in³ 254.0 l Less
Compression Ratio 9.2:1 9.2:1 Less
Aspiration Turbocharged-Aftercooled Turbocharged-Aftercooled Less
Rotation from Flywheel End Counterclockwise Counterclockwise Less
Flywheel Teeth 255 255 Less
Weight - Dry 55300.0 lb 25084.0 null Less
Oil Change Interval 5000 hours 5000 hours Less
Ignition, Protection ADEM™ A3 ADEM™ A3 Less
Stroke 11.8 in 300.0 mm Less
Bore 11.8 in 300.0 mm Less

Capacity for Liquids

Cooling System 194.0 gal (US) 734.0 l Less
Lube Oil System - Refill 272.0 gal (US) 1030.0 l Less

Engine Design

- Proven reliability and durability- Ability to burn a wide spectrum of gaseous fuels- Robust diesel strength design prolongs life and lowers owning and operating costs- Broad operating speed range


Meets U.S. EPA Spark Ignited Stationary NSPS Emissions for 2010/11 with the use of an oxidation catalyst

Lean Burn Engine Technology

Lean-burn engines operate with large amounts of excess air. The excess air absorbs heat during combustion reducing the combustion temperature and pressure, greatly reducing levels of NOx. Lean-burn design also provides longer component life and excellent fuel consumption.

Ease of Operation

- High-strength pan and rails for excellent mounting and stability- Side covers on block allow for inspection of internal components

Advanced Digital Engine Management

ADEM A3 engine management system integrates speed control, air/fuel ratio control, and ignition/detonation controls into a complete engine management system. ADEM A3 has improved: user interface, display system, shutdown controls, and system diagnostics.

Full Range of Attachments

Large variety of factory-installed engine attachments reduces packaging time.


Every engine is full-load tested to ensure proper engine performance.

Gas Engine Rating Pro

GERP is a PC-based program designed to provide site performance capabilities for Cat® natural gas engines for the gas compression industry. GERP provides engine data for your site's altitude, ambient temperature, fuel, engine coolant heat rejection, performance data, installation drawings, spec sheets, and pump curves.

Product Support Offered Through Global Cat Dealer

More than 2,200 dealer outletsCat factory-trained dealer technicians service every aspect of your petroleum engineCat parts and labor warrantyPreventive maintenance agreements available for repairbefore-failure optionsS•O•SSM program matches your oil and coolant samples against Caterpillar set standards to determine:- Internal engine component condition- Presence of unwanted fluids- Presence of combustion by-products- Site-specific oil change interval

Over 80 Years of Engine Manufacturing Experience

Over 60 years of natural gas engine productionOwnership of these manufacturing processes enables Caterpillar to produce high quality, dependable products- Cast engine blocks, heads, cylinder liners, and flywheel housings - Machine critical components- Assemble complete engine

Web Site

For all your petroleum power requirements, visit

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