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CAT 3306 Engines

Caterpillar 3306 Engines For Sale

Red Logo of Big Bear Engine CompanyThe old adage, “If it ain’t broke don’t fix it,” still rings true today with the Caterpillar 3306 engine. You can’t go wrong with this well-engineered inline-six. Forty years after being introduced, this engine continues to power America. It is known for its reliability, ease of maintenance, and stamina to get any job done. The 3306 will easily go a million miles before a major overhaul is required.

Our component build CAT 3306 engines have improved on Caterpillar’s original design in order to produce more horsepower, higher torque, and increased fuel economy. Our extended long blocks are primarily built with brand new parts, exactly to OEM specifications. They also come with an industry leading warranty. Some non-wearable parts are rebuilt from cores, such as inlet and outlet connections, aftercoolers, solenoids, etc. Note that these are aftermarket hybrid engines, built to 9Y Arrangement legacy specifications. The 9Y Arrangement is a good replacement for more than 20 popular dozers, scrapers, tractors, wheel loaders, dump trucks, compactors and rollers.

CAT 3306 Extended Long Block Engines:

Our 3306 component built engines (also known as extended long blocks) come with everything you need to replace your existing failed engine. These industrial rated CAT 3306 engines are assembled using brand new aftermarket and OEM ISO 9001 parts, are built to exact OEM tolerances, and have less than a 1-percent parts failure rate. As a general guide, an extended long block is roughly 75-percent of a complete engine build and is a perfect solution for the customer who has an existing 3306 but has experienced a catastrophic internal failure. Most customers will merge the extended long block with salvageable parts from the original engine. In addition to our extended long blocks, we also offer standard remanufactured long blocks built to your specific serial number. A traditional remanufactured 3306 is more suitable if you have an older PC (Pre Combustion Chamber) model vs. the DI (Direct Injected) version. Our extended long block 3306DI model engines include:

• Block
• Cylinder Head
• Camshaft and Lifters
• Crankshaft
• Connecting RodsBronze-Colored CAT 3306 Engine
• Rocker Assemblies
• Gaskets, Liners, Rings, Seals, Wrist Pins, Bearings
• Injectors
• Oil Pump and Water Pump
• Oil Cooler
• Oil Filters
• Intake and Exhaust Manifolds
• Housings (Front and Rear)
• Brackets and Pullys
• Fuel Injector Pump
• Turbo
• Oil Pan
• Standard 12 Months Parts Replacement Warranty
• 1 and 2 Year Extended Parts/Labor Warranties Also Available

CAT 3306 Engine History

Ask any old-time trucker about the CAT 3306 and they will all tell you the same thing: the old girl is reliable. The Caterpillar 3306 remains one of the best designed and most dependable engines Caterpillar ever produced. The 3306 is an inline-six engine that displaces 10.5L and can run on diesel fuel or natural gas.

CAT’s 3306 was initially manufactured in the early 1970s, replacing the older 1673 andBlue Logo of AERA 3160 model engines. The 3306 was widely used in the CAT 225 Excavator in 1973 and was manufactured all the way up until the late 1990s, when emissions technology changed. The C7 and C9 replaced the 3306 starting in 2004, after Tier III and Tier IV emissions regulations became standard.

The CAT 3306 is known for its reliability, which is a direct result of its uncomplicated design. Earlier versions were equipped with precombustion chambers, but were later replaced with direct injection (where the combustion chamber is integrated into the piston). The newer, left hand scroll fuel system is also highly reliable (vs. the older sleeve metering fuel systems).

It won’t win any races, but the 3306 is one heck of a workhorse, capable of producing 563 to 967 lb-ft of torque, depending on application. Modern CAT 3306s fitted with injector and turbo upgrades can turn out more than 1000 lb-ft of torque. Consequently, average horsepower ratings for modern CAT 3306 engine’s equipped with turbo and injector upgrades range between 218 to 360 hp.

Early engines averaged much lower horsepower ratings, usually 180 - 200 hp, with later models producing 270 hp on a good day. The original max horsepower rating was 270 hp (by way of JWAC, or Jacket Water After Cooled) and 300 hp ATTAC (Air to Air After Cooled) at the end of the 3306’s lifecycle. The original CAT 3306 is similar to the CAT 3406 except for the fact that it only features two valves per cylinder (vs. four valves per cylinder on the 3406). All new CAT 3306DI engines utilize four valves per cylinder. The original indirect injection engines (i.e. precombustion chambers) consume 8 to 11 gallons of diesel fuel per hour on average, but modern direct injection CAT 3306s return notably higher fuel efficiency. Unlike the CAT 3406, the 3306 natural gas application is just as durable as the diesel version.

The CAT 3306 engine was a workhorse in the company’s heavy-duty diesel engine lineup for more than 25 years and was mass produced in quantity. The engine was used in a lot of D6 and D7 dozers, and 12G, 14G and 140G motorgraders, but is also found in everything from rollers, scrapers, excavators, dump trucks, cement mixers, gensets, front end loaders and industrial pumps. Back in the 1970s and 1980s, the 3306 used by all of the major truck manufacturers such as Peterbuilt, Kenworth and Freightliner—although those engines would never make the cut today with much more powerful engines available in Class 8 vehicles. The 3306 is also found in a lot of vocational trucks, step vans, delivery vehicles and bread trucks. The CAT 3306B was a huge hit in the marine industry and was successfully installed in millions of small boats, from tugs, dredges, ferries and pump boats, to drifters, trawlers and fireboats.

Caterpillar 3306 Specs

Engine Data

ConfigurationInline 6 Cylinder
Displacement10.5 L, 638 cubic inches
Bore x Stroke4.75" x 6.00"
Cylinder HeadCast Iron with six head bolts per cylinder
Engine BlockCast Iron with wet cylinder liners
Firing Order1-5-3-6-4-2
Compression Ratio15.0:1 to 17.5:1 (depending on application)
InjectionDirect Injection with scorll-type injection pump and mechanical delivery, Indirect Injection/precombustion with sleeve metering mechanical fuel delivery
AspirationTurbocharged, Turbocharged and Aftercooled, Naturally Aspirated (depending on application)
Valve TrainOHV, 2 valves per cylinder
Weight2265 lbs (Dry)
Oil Capacity10.25 Gallons
GovernorHydramechanical or Woodward PSG
Horsepower230- 350 hp (depending on application)
Torque585 lb-ft (depending on application)


Give us a call today at 844-340-4114 for immediate sales and support for the Cummins 4BT, Cummins 6BT or CAT 3306. If you have any questions, check out our FAQ Page. We are always ready to help or just listen to your crazy off-roading adventures!

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