The need for speed greatly affected engine longevity as the builders tried to cram more and more HP into their boats. Unfortunately those older engine rooms couldn't take bigger motors so the answer was to get more HP out of the same size motors. A new Cabo 43 for example is now powered with 900 HP MAN V8-900CRM's. Those engines are almost 900 CI displacement and they fit into 40-45 foot sports yet the maintenance requirements are large money. You don't even want to ask what the yearly maintenance cost following MANs recommendations. Although the 3208 has been discontinued (1999) there are many still in service; the most popular applications for these engines are marine applications.The Caterpillar TA 3208, 375 HP will drive a 13T boat along at 35 knots.

Typical Applications for the Cat 3208 Diesel Engine

Caterpillar 3208TA EngineAlthough the 3208 has been discontinued (1999) there are many still in service; the most popular applications for these engines are marine applications.

The Caterpillar TA 3208, 375 HP will drive a 13T boat along at 35 knots.

The difference between a NA engine and a highly boosted engine is huge when longetivity is the primary goal. Put a lower HP variant of the 3208 in a lobster boat or trawler and they run for many thousands of hours. Put the highest power variant in a big sportfish and run it 200 off the top and life is greatly reduced. This is really no different than any other diesel engine, the same holds true for an old 671NA compared to it's highly boosted counterpart 671TI producing more than twice the horsepower. As Jags points out there is also a line you cross where age becomes a factor more than hours. Hour meters like odometers seem to be the predominant decision logic when looking at older engines which is really just a small indicator of the life left in any engine. How the engines were maintained is of course a huge factor but the application (boat size, weight and cruise rpms) play a huge part in the longetivity equation. A 40 something sportfisherman running a couple hudred off the top it's whole life compared to a displacement hull running slow speeds is like night and day no matter what engine is installed.

Marine applications include main and auxiliary engines on the following vessels.
  • Cruise ships (aux)
  • Ferries (aux)
  • General cargo ships (aux)
  • Yachts and pleasure cruisers (main)
  • Offshore (aux)
  • Tugs (aux)
  • Fishing boats (aux)

Other applications for the 3208 caterpillar engine include:

  • Government Service Vehicles – garbage trucks, snow ploughs and blowers, delivery trucks and school buses.
  • Agricultural Machinery – combine harvesters, tractors, sprayers, and fork lift trucks.
  • Industry – excavators, bulldozers, cranes, low-loaders, articulated mining trucks, and backhoes.
  • Power Generation – emergency generators and temporary and permanent industrial power station standby gensets.

Design of the 3208 Diesel Engine
The original caterpillar 3208 diesel engine was a 225hp, 636 cubic-inch capacity V8 design. It did not have cylinder liners, but many engineering companies would re-bore the blocks and fit oversize pistons and rings rather than throw the engines away. (They were known as “throw away engines,” which the makers claim was one of the design criteria.)

The 3208 emerged in 1973 as a turbocharged version but in 1981, major design mods such as stronger internal rotating parts, three-ring pistons, and beefed up oil and water pumps. The cooling system was also upgraded to include a bigger heat exchanger and seawater pump to cool the engine oil, exhaust manifolds, and turbochargers with the expansion tank and thermostats also being modified.

It was used in many applications but soon became a firm favorite with the yachts and pleasure boats fraternity, with the larger vessels having twin turbo-charged engines fitted.

Unfortunately, the engine was a bit of a gas guzzler and failed to meet the new internal combustion exhaust emission laws which were due to come into force in the new millennium; therefore it was discontinued in 1999.

 The 375 Hp engines we see in commercial use average 10,000 hrs between rebuilds. If it is a 225 or 250 hp natural in a trawler style vessel that gets run alot, you will see upwards of 20,000 or more.

3208 Specifications

3208 Marine Propulsion Ratings by Rating Class

Marine Ratings Definitions

"A" Ratings


Continuous A Rating
Load factor: 80% to 100% time at rated rpm. Typical hours/year: 5000 - 8000. "A" rating typical applications: for heavy-duty service in vessels such as freighters, tugboats, bottom drag trawlwers and deep river towboats when the engine is operated at rated load and speed up to 100% of the time without interruption or load cycling. For 3600 engines only: Continuous Service Rating is suitable for continuous duty applications, including dredges, for operation without interruption or load cycling. Maximum Continuous Rating is generally used for vessel applications involving varying loads. The engine power actually produced is limited by application guidelines, leaving a power reserve for unusual operating conditions.

"B" Ratings


Medium Duty B Ratings
Load factor: 40% to 80%. Up to 80% time at rated rpm. "B" rating typical time at full load: 10 hours out of 12. Typical hours/year: 3000 - 5000. Typical applications: Vessels such as midwater trawlers, purse seiners, crew and supply boats, ferries and towboats where locks, sandbars and curves dictate frequent slowing and engine load and speed are constant with some cycling.


"C" Ratings


Intermittent C Ratings
Load factor: 20% to 80%. Up to 50% time at rated rpm. Typical time at full load: 6 hours our of 12. "C" rating typical applications: Vessels such as ferries, harbor tugs, fishing boats moving at higher speeds out and back (i.e. lobster, crayfish and tuna) off shore service boats and also displacement hull yachts and short trip coastal freighters where engine load and speed are cyclical. Chp - Fast commercial and passenger vessels and cruising yachts with moderate load factors.

"D" Ratings


Patrol Craft D Ratings
Load factor: Up to 50%. Up to 16% time at rated rpm. Typical time at full load: 2 hours out of 12. Typical hours/year 1000 - 3000. "D" rating typical application: Planing hull vessels such as off-shore patrol boats, customs, police and some fire and fishing boats. Also used for bow and stern thrusters.


"E" Ratings


High Performance E Ratings
Load factor: Up to 30%. Up to 8% time at rated rpm. Typical time at full load: 1/2 hour out of 6. Typical hours/year 250 to 1000. "E" rating typical applications: Planing hull vessels such as pleasure craft, harbor patrol, harbor master and some fishing and pilot boats.







If you're looking for general boating parts, head to West Marine Online and check out their specials. If you are in search of model-specific parts, search your local CAT dealer.