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Cat 3304 Engine

CAT 3304 Engines For Sale

CAT 3304 EngineThe 3304 Caterpillar Engine is an in-line, four-stroke-cycle engine that is capable of 95 bhp at 100% power, and 71 bhp when workload is reduced to 75 percent. The Caterpillar 3304 engine was released in 2009, classified as a heavy-duty industrial engine that operates on natural gas as opposed to diesel fuel. Cat declares that the 3304 has track record of reliability, and a capability to burn a wide spectrum of gaseous fuels that prolongs the engines life while lowering owning and operating costs.

Engine Applications and Uses

  • Industrial

Common CAT 3304 Engine Problems & Failures

We noticed some recurring themes from clients who intending to replace their Caterpillar 3304 engines. So, we have gathered a list of recurrent problems that are often reported. Some of the issues featured below may mean your engine has run out of time, nonetheless, some may also be salvageable if caught in good time..

AERA Association Member

  • Spun Crankshaft Bearings
  • Cracked Cylinder Head(s)
  • Camshaft Failure
  • Connecting Rod Failure
  • Crankshaft Failure
  • Dropped Valves
  • Extreme Blow By
  • Lack of oil or oil pressure
  • Lifter/Roller Failure
  • Over Fueling
  • Scored Pistons and Liners

CAT 3304 Engine Replacement Options

Sometimes the truth is... your engine is beyond saving, however, there are several causes than can impair your engine, but not all mean your engine is eternally doomed. At times, your 3304 Cat Engine may just need a few new parts, or maybe it just needs a brief refreshment to keep it in good shape. We do in fact appreciate that considerations such as time, money, availability, etc. will all impact your decision making. Therefore, we have provided some insight by presenting both pro’s and con’s of a new engine from a dealer.

Remanufacturing Process

For those of you reading this that are luckless enough to have seen your engine suffer a dreadful failure, a remanufactured 3304 Cat long block engine would be the ideal answer. Moreover, if you have good re-usable external components that are still in good nick, Big Bear Engine Company informs you that these can be salvaged from your much-loved Caterpillar 3304 engine. Most importantly, this would be a good substitute if your trying to work to a budget.

We constantly strive to uphold a professional level of service, whatever the task. In the realm of remanufacturing, we guarantee this level of quality is sustained by first executing a full core tear down, cleaning, inspection, and machining of the CAT 3304 engine. This is carried out on every engine before it leaves our facility.

It is crucial to note that all of our Caterpillar 3304 engine remanufactured long blocks are built with both reman and new parts. Therefore, we do not just recondition or refurbish old parts, instead, we fully rebuild the old 3304 Cat engine back to its original OEM specs.

Thorough Cleaning

Careful cleaning is essential during the process; therefore, we endeavor to relieve your engine of any contaminations that could promote or cause both component failure or engine failure. This is done by first stripping the 3304 Cat engine, then putting the blocks, heads, rods, crankshafts, and camshafts through a chemical jet wash or hot tank.


Before our quality control division inspect the finished product, the crankshafts are precision machined to the precise tolerances, polished and magnafluxed.

Cylinder Heads

Heads are resurfaced to guarantee a proper sealing surface with the block and a finish compatible with today's new gasket materials. Valve height is mic-d and every head is vacuum tested to assure correct valve seating.

Cylinder Blocks

Magnetic particle is used to inspect the block for any cracks or further damage. The cylinders and then bored, honed and again inspected to the specific tolerances. Torque plate honing is performed on particular engines to eradicate the chances of cylinder head distortion when the head is bolted and torqued to the block. This process subsequently removes the main source of engine blow-by. Block surfaces are then machined and inspected to ensure proper finish.


Camshafts are inspected and precisely machined to provide correct lift. Lobs are measured with a micrometre to make sure OEM tolerances are met.

Connecting Rods

In order to attain an even distribution of stress on the bearings, the connecting rods are cleansed, then machined to the OEM specs before being honed to the traditional diameter of the original equipment. New bushings are also installed and machined in all bushed rods, every rod is also inspected for any bend and/or twist.

New Parts

Great performance and reliability are what we strive for, therefore, all CAT 3304 engines will obtain a set of new parts, specifically - pistons and rings, bearings, gaskets and sealers, and liners. These parts are both OEM and Aftermarket when accessible.

Request a Quote

Please fill out the form below with your information and request. A member of our staff will be with you shortly.

Remanufactured Engines Standards

To best define remanufacture, would be to make as close to new as possible. In pursuit of this, all wearable parts are routinely replaced. All 3304 Cat engine core materials are then carefully inspected and examined against the original equipment specifications for correct dimensional tolerances. Replacement parts are new or requalified. If new, parts are made in the same production methods as the original equipment. Testing is also performed to manufacturer specifications and original production standards.

CAT 3304 Long Block Parts List:

  • Cylinder Block
  • Complete Loaded Cylinder Head
  • Intermediate Cover
  • Timed Front Gear Group
  • Pistons
  • New Upper and Lower Gasket Set
  • Camshaft
  • Followers/Lifters
  • Liners
  • Rings
  • Crankshaft
  • Connecting Rods
  • **1 Year Warranty

*Note: Big Bear Engine Company can provide new oil pumps, oil coolers, water pumps, turbos, injectors and fuel pumps for additional cost with the long block but will not come assembled to the engine.

**First 6 Months Parts & Labor, Second 6 Months Parts Replacement Only. Ask your sales representative for a full copy of our remanufactured long block warranty.

CAT 3304 Spec

Engine Data

Min Power 71.0 bKW
Max Power 71.0 bKW
Frequency 1800 rpm
Bore 121 mm
Stroke 152 mm
Displacement 7.0 L
Engine Configuration Continuous
Aspiration Naturally Aspirated
Length 45.6 in
Width 29.28 in
Height 46.11 in
Weight Net (dry) 757 Kg

Give us a call today at 844-340-4114 for immediate sales and support for the Cummins 4BT, Cummins 6BT, 6CT, ISC, 855, QSB 4.5 L 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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