Request Info

Contact Us For Price


Maximum Rating325 BHP (242 bkW)
EmissionsNSPS Site Compliant Capable
Displacement891 in³ (14.59 l)
Minimum Rating215 BHP (160 bkW)
Tough and durable, built on the industry-standard G3400 platform bring maximum uptime and low operating cost to your operation. G3406 engines meet the most demanding continuous duty gas compression applications with virtually no unscheduled downtime. Ideal applications for G3406 engines include gas lift, gas gathering, and wellhead gas compression. Cat G3406 gas engine. Ratings: 160-242 bkW (215-325 bhp) @ 1800 rpm are NSPS site compliant capable with customer-provided air-fuel ratio control and aftertreatment or available for non-regulated areas.


Maximum Rating325 BHP (242 bkW)
EmissionsNSPS Site Compliant Capable
Displacement891 in³ (14.59 l)
Minimum Rating215 BHP (160 bkW)
Compression Ratio9.4:1
AspirationNaturally Aspirated or Turbocharged-Aftercooled
Rotation from Flywheel EndCounterclockwise
Flywheel and Flywheel HousingSAE No. 1
Flywheel Teeth113
Weight - Dry3000 lb (1360.8 kg)
Cooling System10 gal (US) (37.9 l)
Lube Oil System - Refill20 gal (US) (75.7 l)
Oil Change Interval750 hours
Ignition, ProtectionAltronic III
Stroke6.5 in (165 mm)
Bore5.4 in (137 mm)

Benefits and Features

Rich burn engine design easily meets emission requirements - 0.5% O2 rating meets U.S. EPA Spark Ignited Stationary NSPS Emissions for 2007/8 and 2010/11 with the use of aftermarket AFRC and TWC

Large variety of factory-installed engine attachments reduces packaging time

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

GERP is a web-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.

More than 2,200 dealer outlets Cat factory-trained dealer technicians service every aspect of your petroleum engine Cat parts and labor warranty Preventive maintenance agreements available for repairbefore-failure options S•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 60 years of natural gas engine production Ownership 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

For all your petroleum power requirements, visit

Standard Equipment

  • Air cleaner — heavy-duty
  • Air cleaner rain cap
  • Service indicator
  • Governor — Woodward PSG mechanical
  • Governor locking — positive control
  • Thermostats and housing
  • Jacket water pump
  • Aftercooler water pump
  • Aftercooler core
  • Watercooled exhaust manifolds
  • Dry exhaust elbow
  • SAE No. 1 flywheel
  • SAE No. 1 flywheel housing
  • SAE standard rotation
  • Gas pressure regulator
  • Natural gas carburetor
  • Altronic III ignition system
  • Service meter
  • Crankcase breather — top mounted
  • Oil cooler
  • Oil filter — RH
  • Auxiliary oil reservoir
  • Oil pan — full sump
  • Oil filler in valve cover, dipstick — RH
  • Engine supports
  • Paint — Cat yellow
  • Crankshaft vibration damper and drive pulleys
  • Lifting eyes

Optional Equipment

  • Battery chargers
  • Charging alternators
  • Charging alternators f/u/w c customer supplied shutoffs
  • Ammeter gauge
  • Ammeter gauge and wiring
  • Control mounting
  • PSG Woodward governor
  • Radiators
  • Non-sparking blower fan
  • Blower fans for customer supplied radiators
  • Fan drives for customer supplied radiators
  • ATAAC conversion
  • Aftercooler
  • Expansion tank
  • Heat exchangers
  • Flexible fittings
  • Elbow
  • Flange
  • Pipe
  • Rain cap
  • Muffler
  • Fuel filter
  • Natural gas valve and jet kits
  • CSA shielded ignition
  • Wiring harness
  • Gauges and instrument panels
  • Auxiliary oil reservoir removal
  • Lubricating oil
  • Vibration isolators
  • Auxiliary drive pulleys
  • Enclosed clutch and clutch support
  • Front stub shaft and flywheel stub shaft
  • Air starting motor
  • Electric air start control
  • Air pressure regulator
  • Air silencer
  • Electric starting motor— single 12- and 24-volt
  • Starting aids
  • Battery sets, cables, and rack
  • Damper guard