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Cat 3408 Engine

CAT 3408 Engines For Sale

The 3408 Cat engine is a V8 version of the renowned 3406. The Caterpillar 3408 engine was first produced in the 1970’s and continued up until 1985. At the very beginning of its release, the 3408 Cat engine was considered fairly expensive until it earned its decent reputation, subsequently becoming very popular, especially in marine applications.  The 3408 has a life expectancy of 16,000 hours which is just shy of 2 years. OEM parts are available to this day for 3408 marine engines, thankfully.  The 3408 Cat is undoubtedly an extremely versatile engine, the 3408 can be used in marine vessels, power generation, construction, emergency power, mining, and oil and gas. The 3408 Cat models are ideal for medium-sized vessels such as shrimp boats, tugboats, and ferries.

Engine Applications and Uses

  • Marine
  • Power Generator
  • Construction
  • Power
  • Mining
  • Oil & Gas

Common CAT 3408 Engine Problems & Failures

Sadly, engines go wrong, some are savable, and some are just too far gone and/or worth the time and money, subsequently meaning the engine is no more. Listed below we have included some common issues we hear from customers who wish to replace their Caterpillar 3408 engine.

AERA Association Member

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

Caterpillar 3408 Engine Replacement Options

Regrettably, there is an array of issues that can halt your engine. Some instances mean that your only alternative is to replace it. However, every so often you may just need a few more parts to bring it back to life, or maybe, the engine merely needs a well-earned refreshment. We can appreciate that factors such as cost, time, and availability will determine your decision making - so let us inform you of the pro’s and con’s of a new engine from the dealer.

Remanufacturing Process

If you have the misfortune of being the victim of a serious internal engine failure but are lucky enough to be able to re-use some of its external components…a remanufactured 3408 Cat long block is a good decision indeed. In addition, a long block is also ideal if your hoping to spend as little money as possible.

In order to achieve this, our team of machinists and engine builders will do a full core tear down, cleaning, inspection, and machining of the engine before it leaves our facility, guaranteeing every engine is in good condition each and every time.

However, it is crucial to point out that all of our Caterpillar 3408 remanufactured long blocks are assembled with a mixture of both reman and new parts. We do not recondition or refurbish old engine parts, instead, we entirely rebuild the old 3408 Cat motor back to OEM specs.

Thorough Cleaning

To avoid the early demise of both parts and the 3408 Cat entirely, we remove all the unwanted impurities by stripping the blocks, heads, rods and camshafts which are then meticulously cleaned in a chemical jet wash or hot tank.


The quality control department inspect the crankshafts after they are precision machined to exact tolerances, polished & magnafluxed.

Cylinder Heads

To guarantee a proper sealing surface with the block, and to achieve a finish fitting with the latest gasket materials, the heads are resurfaced. Valve height is mic-d and every head is vacuum tested to assure correct valve seating.

Cylinder Blocks

Blocks are carefully inspected by magnetic particle for any cracks or damage. In an effort to ensure the avoidance of cylinder head distortion after the head is bolted and torqued to the block, the cylinder heads are bored and honed to precise tolerances. In turn, this significantly reduces a prominent cause of engine blow-by. Block surfaces are machined and then inspected to achieve a proper finish.


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

Connecting Rods

Brand new bushings are installed and machined in all bushed rods. Every rod is then carefully inspected for any bend and/or twist. Connecting rods are cleaned, then machined to O.E.M. specifications and honed to the usual diameter of original equipment for even distribution of strain on the bearings.

New Parts

Pistons and rings, bearings, gaskets and seals, and liners are all brand new as standard for our 3408 long blocks. These new parts guarantee dependable performance and reliability during the course of the now extended life of your engine. The new parts are a mixture of OEM and Aftermarket when available.

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

In addition, wearable parts are replaced every time, all the 3408 Cat engine’s core materials are then inspected and examined against the original specifications to ensure correct the dimensional tolerances are met. After all, the aim of remanufacturing is to make it as close to new as possible. Alternate parts are either new or requalified. If new, the parts are produced in the exact same manufacturing process as the original Caterpillar 3408 engines. Testing is then performed to manufacturer specifications and original production standards.

CAT 3408 Long Block Parts List:

  • Timed Front Gear Group
  • Cylinder Block
  • Complete Loaded Cylinder Head
  • Connecting Rods
  • Crankshaft
  • Intermediate Cover
  • Pistons
  • Liners
  • Rings
  • **1 Year Warranty

*Note: We 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 3408 Spec

Engine Data

Maximum Power 298.0 bkW
Emissions NSPS Site Compliant Capable or non-regulated
Displacement 18.0 l
Compression Ratio 9.7:1
Aspiration Naturally Aspirated or Turbocharged-Aftercooled
Rotation (from flywheel end) Counter-Clockwise
Flywheel and Flywheel Housing SAE No. 0
Flywheel Teeth 136
Weight Net (dry) 1678.0 kg
Oil Chang Interval 750 hours
Ignition, Protection Altronic III
Stroke 152.0 mm
Bore 137.0 mm
Cooling System 54.9 L
Lube Oil System 46.2 L

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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