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The Caterpillar 3306 is a legendary inline 6-cylinder diesel engine known for its durability, power, and exceptional service life. First introduced in the 1970s, the 3306 built upon the success of the 3304 and quickly became one of Caterpillar’s most widely used engines across construction, industrial, marine, and power generation sectors. Available in naturally aspirated, turbocharged, and turbo-aftercooled configurations, the 3306 could be tuned for various applications requiring up to 400+ horsepower. Known for its mechanical fuel injection system, cast-iron wet-sleeve design, and simple serviceability, the engine became a global workhorse and remains in widespread use today—particularly in rebuild-focused fleets, export markets, and marine operations. Even though the 3306 was eventually succeeded by electronic models like the C-10 and C-12, it remains one of the most supported platforms in the aftermarket—especially through trusted sources like Diesel Pro Power. Specification Details Engine Model Caterpillar 3306 Configuration Inline 6-cylinder, 4-stroke diesel Displacement 10.5 Liters (638 cubic inches) Bore x Stroke 4.75 in x 6.00 in (121 mm x 152 mm) Compression Ratio 16:1 (varies slightly by version) Aspiration Naturally Aspirated, Turbocharged, or Turbo-Aftercooled Fuel System Mechanical Direct Injection (various pumps) Cooling System Water-cooled Horsepower Range 170–400+ HP @ 1800–2200 RPM Peak Torque Up to 1,300 lb-ft @ 1400–1600 RPM Emissions Standard Pre-Tier 1 (non-EPA regulated) Dry Weight 2,800–3,100 lbs (varies by configuration) 3306B & 3306C – Later model enhancements with improved block casting and fuel system refinements 3306DI – Direct injection variant for improved combustion and fuel economy 3306T & 3306TA – Turbocharged and turbo-aftercooled models with increased power output 3306 Marine – Custom-configured for propulsion and auxiliary roles with seawater cooling and corrosion protection The CAT 3306 remains in service because of its: Long engine life—often exceeding 20,000 hours with proper care Fully mechanical design—ideal for remote operations or field service Excellent parts support from trusted aftermarket providers High torque output at low RPM for demanding applications Rebuildability with wet sleeves and robust internal components Diesel Pro Power supports the 3306 platform with a full line of aftermarket parts engineered to match or exceed OEM performance, backed by our track record of 40,000+ satisfied customers worldwide. The versatility and power of the 3306 engine made it a go-to solution across a broad range of industries. Today, it’s especially valuable in repower, overhaul, and heavy-duty applications where downtime is costly and simplicity is key. The 3306 was extensively used in heavy Caterpillar machinery and still powers many of these units in active fleets worldwide. CAT 966, 970, and 980 wheel loaders CAT 140, 160, and 16 motor graders CAT 225, 235, 245 hydraulic excavators CAT D6 and D7 crawler tractors CAT 621, 623 scrapers and coal haulers Diesel Pro Power stocks engine rebuild kits, turbochargers, cylinder heads, fuel pumps, and other critical components for this fleet of aging but serviceable heavy equipment. The turbocharged and aftercooled versions of the 3306 were widely used in commercial marine vessels due to their torque curve, long service intervals, and minimal electronics. Small tugboats and crew boats Pilot vessels and harbor workboats Commercial fishing vessels Marine generators (up to 150 kW) Hydraulic winch and pump engines We provide marine-grade parts, including raw water pumps, exhaust elbows, thermostats, seawater strainers, and corrosion-resistant gaskets for 3306 marine engines. The 3306 was a popular platform for industrial generator sets, especially where continuous duty and high-load capacity were required. Prime power for remote sites Standby emergency power (hospital, telecom, municipal) Mobile trailer-mounted generators for rental fleets Industrial facilities with 125–300 kW demand Diesel Pro Power supplies governor parts, sensors, fuel filters, and oil system components to support the 3306 in power generation applications. The 3306 is used in many types of heavy-duty, engine-driven industrial systems where torque and fuel efficiency are critical. Water pumps for irrigation and dewatering Drill rigs and frac pumps Industrial air compressors Belt-driven conveyor systems Grain elevators and feed systems With its reliable power delivery and ease of field maintenance, the 3306 continues to be trusted in harsh environments and remote regions.
Parts for Caterpillar 3306
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Loading... Engine Specifications & Applications of the Caterpillar 3306 Engine
Overview of the Caterpillar 3306 Engine
Caterpillar 3306 Engine Technical Specifications
Common Engine Variants
Why the Caterpillar 3306 Remains a Popular Engine in the Aftermarket
Applications of the Caterpillar 3306 Engine
1. Construction and Earthmoving Equipment
Common Equipment:
2. Marine Propulsion and Auxiliary Systems
Marine Applications:
3. Power Generation and Standby Use
Generator Applications:
4. Industrial, Agricultural, and Oilfield Equipment
Common Installations:
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