The introduction of an entirely new series of diesel engines is a rare occurrence in the marine industry. Caterpillar accomplished this feat with the introduction of its entirely new 3500 Series earlier this year. This new family of high-speed, heavy-duty diesel engines in the 800 to 1,600 bhp (600-1,200 kw) range is designed to provide optimum value for a wide variety of applications.
The 3500 family will ultimately consist of V8, V12, and V16 models. The V12 (3512) was the first model produced, for limited distribution in the United States and Canada, with continuous and intermittent ratings of 1,055 bhp and 1,200 bhp, respectively. Worldwide 3512 availability was anticipated during the third quarter of this year. Limited geographical distribution of the V8 (3508) is planned for the fourth quarter 1981; the V16 (3516) is similarly planned for 1982.
The 3500 Series is an additive to the company's 300 Series engine. The latter will remain in the Caterpillar product line to serve customers and the company's own product needs.
The 3500 Series engines were designed to produce 100 intermittent horsepower (74.6 kw) per cylinder, industrial configuration. Displacement is 2,105 cubic inches for the 3508, 3,158 cubic inches for the 3512, and 4,211 cubic inches for the 3516. All three models are four-cycle, dual-turbocharged, and jacket water aftercooled. The 3500 Series will be available in marine propulsion and large marine auxiliary configurations.
Typical 3512 applications include workboats, fishboats, dredges, cranes, and standby and prime power installations. The 3512 marine propulsion and marine auxiliary configuration has a 60-degree Vee to reduce physical engine dimensions for ease of installation. Inlet manifolds, aftercooler, and exhaust manifolds are mounted in the Vee for compact, uncluttered design.
Engines must perform with a minimum of downtime to keep operations profitable. The 3500 Series offers conservative loads, stresses, and speeds in a large-displacement, low-bmep package. From metallurgy through machining, assembly, and testing, all component specifications and tolerances are accurately maintained to assure customer value.
The 3500 Series has a large displacement of 263 cubic inches per cylinder. Turbocharging and aftercooling further increase engine performance and efficiency while decreasing thermal load. The cam-actuated, unit injection fuel system provides outstanding performance and economy. Three-ring piston design simultaneously reduces internal engine friction while maintaining oil control and compression.
Another benefit of the 3500 Series is that commonality of parts reduces inventory requirements, increases parts interchangeability, and reduces service time due to maintenance personnel familiarity. All 3500 Series cylinder heads, connecting rods, valves, pistons, and numerous other components are interchangeable.
Specialized attachments specifically designed for the 3500 Series include generator sets, matching marine transmissions, optional bases and foundation hardware, cooling systems, and various air cleaner arrangements.
The 3500 Series represents a fine balance of advanced engine design and application flexibility. High-speed capability allows the engines to compete effectively in applications horsepower and speeds not previously available with existing Caterpillar diesel engines. Finally, the 3500 Series engines are mechanically simple and efficient, and use proven components that have a high degree of commonality.
With the introduction of the 3500 Series engines, Caterpillar now has one of the most complete, technologically advanced engine product lines in the world — a product line that is celebrating its 50th anniversary in 1981.