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Diesel Power Review (continued) per hour, and the bsfc was reduced by 10 points. At this power rating, the VTA28- M is said to be lighter in weight and more compact than comparable ma- rine diesels. In addition to the light- er weight-to-power ratio, this also means there is more walk-around room in the engine compartment for service and ease of maintenance. The first marine models of its new B and C Series of lower-horsepower diesels, introduced in 1985, expands the Cummins marine product line to 61 bhp at the lower end. The B Series consists of 4- and 6-cylinder models with displace- ments of 3.9 and 5.9 liters, ranging from 75 to 152 bhp at 2,500 rpm, rated 2,500 for intermittent duty and 2,800 for maximum duty. The B Series is capable of providing main propulsion in a wide variety of ma- rine applications. The C Series propulsion engines, which will be available in the second half of this year, comprise six-cylin- der units with a displacement of 3.8 liters, ranging from 158 to 204 bhp. Cummins has also increased en- gine horsepower ratings for its NT855-M and KT855-M marine models. The NT855-M is now avail- able rated 360 bhp at 2,100 rpm, up from the former rating of 295 bhp at 1,950 rpm. Its continuous-duty rat- ing has been increased from 270 bhp to 300 bhp at 1,800 rpm. The KT19-M's intermittent rat- ing of 510 bhp at 2,100 rpm has been available since 1984. Its continuous- duty rating has now been increased from 365 bhp to 425 bhp at 1,800 rpm. DAIHATSU Circle 18 on Reader Service Card A new type of engine, the DL Series, which features low fuel con- sumption, low quality fuel burning capability, and low load operability, has been developed by Daihatsu Diesel Manufacturing Company Ltd. of Japan, represented in North America by Daihatsu Diesel (U.S.A.) Inc. The DL Series engines—DL-20, DL-26, DL-28, and DL-32—are a medium-speed type of 600 to 1,000 rpm, with outputs covering the range from 750 to 3,000 bhp. They are suitable for both main propul- sion and auxiliary generating appli- cations. Extensive testing under various conditions on all parts of these en- gines was carried out at the Daihat- su laboratory and factory in Osaka before they were placed on the mar- ket. The company's traditional de- sign concepts—simple and sturdy construction, easy maintenance. and lower maintenance costs—are fully incorporated in the DL Series. The company reports an increasing number of orders for the DL engines from shipowners overseas. DETROIT DIESEL Circle 19 on Reader Service Card Detroit Diesel Allison (DDA) re- cently introduced the 12V-92TA marine model, a turbocharged, af- tercooled engine that incorporates "Forward Plan" components and features an increased horsepower rating of 545 bhp for workboat ap- plications. Forward Plan components fea- ture a water-cooled turbocharger and exhaust system current with application regulations, two-pass af- tercooler, and advanced air induc- tion system combined to offer im- proved fuel economy at increased horsepower. Similar components will be incorporated into the Series 92 six-, eight-, and 16-cylinder mod- els in 1987. The 8V92TA version will be rated at 365 bhp for work- boat applications and will replace the currently offered 12V-71N mod- el. In addition, the Forward Plan components will be featured on the 1987 version of DDA's 12V71TA model, with improved fuel economy and an increase in horsepower to 400 bhp. A current R&D project being con- ducted by DDA in conjunction with the Maritime Administration, U.S. Department of Transportation, in- volves studying the benefits of De- troit Diesel Electronic Control as applied to the 149 Series for tow- boat applications. This system em- ploys two Electronic Control Mod- ules connected via a high-speed communication link to control injec- tion and governing on the 16V- 149TIB engine. This, combined with turbocharger developments providing excess air flow for burst power and transient conditions with reduced parasitic losses, will allow DDA to offer smaller engines to replace larger engines in marine ap- plications. As with the Series 71 and Series 92, the naturally aspirated 149 Se- ries engines will be replaced with Forward Plan models for the eight-, 12-, and 16-cylinder T and TI mod- els. DEUTZ/MWM Circle 20 on Reader Service Card Two major West German diesel engine manufacturers, Klockner- Humboldt-Deutz AG of Cologne, and Motoren-Werke Mannheim AG of Mannheim, have merged to form Deutz/MWM, and now offer one of the broadest power ranges of diesel engines in the world. This merger brings together two engine builders with a total of more than 230 years of experience, as well as a combined reputation for quali- ty, reliability, and service excel- lence. The KHD Group's Engine Divi- sion will be restructured with all activities involving the water-cooled engine business being combined at Mannheim. KHD will relocate its medium and big engine activities in development, sales, and parts man- ufacturing to Mannheim in combi- nation with the engine program of MWM. The medium-sized and big engine built in Mannheim and Co- logne will be manufactured and marketed under the trade name Deutz/MWM. The formation of Deutz/MWM will offer an expanded range of ma- rine and stationary prime movers, for propulsion and electric power generation, to world markets includ- ing North America. The North American headquar- ters of the new company is located in Montreal, with a division based in Atlanta. ELECTRO-MOTIVE Circle 21 on Reader Service Card The latest diesel engine design from the Electro-Motive Division (EMD) of General Motors is the 710G Series, offering increased reli- ability, better fuel economy, and the potential for significantly higher horsepower in the future. The new design is an evolutionary develop- ment of EMD's turbocharged, uni- flow-scavenged, two-stroke cycle en- gines. The simplicity of design, maintainability, and high reliability of those engines have been retained in the new design. The 16-cylinder 710G is rated 3,600 bhp at 900 rpm for marine applications. It has a bore of 9.06 inches, stroke of 11 inches, and dis- placement of 710 cubic inches per cylinder. The design of the 710G is a logical outgrowth of EMD's current pro- duction series, the 645F engines. The most recent version of that series, the 645FB, is the result of a succession of incremental improve- ments. From 1980 to 1983, for exam- ple, the fuel efficiency of the 645F was increased by six percent and the compression ratio was raised from 14.5:1 to 16:1. The 710G can also be viewed as a new dimension in engine design in terms of its potential for future development. Greater displacement and an advanced-design turbo- charger give the 710G the capacity for significant increases in horse- power. Thus, the 710G combines innovation with the proven technol- ogy of its predecessor, but its poten- tial makes it more than just this year's model. The 710G is EMD's most fuel- efficient engine to date; full-load consumption has been improved by nine percent over the 1980 645F3 engine. The longer stroke and added dis- placement of the 710G led to struc- tural improvements in the engine, including: new Model G crankcase; larger-diameter plunger injectors; larger-diameter crankshaft; longer cylinder liner; and longer piston and rod assembly. Overall dimensions also increased; the 710G is 4% inches longer and 1% inches high- er. The added engine length is the result of a larger, extremely efficient turbocharger. Entry to the turbine was streamlined to improve gas flow, and an improved exhaust dif- fuser also reduces flow restriction. The turbocharger is deeper to ac- commodate a larger annulus for a smoother and less restrictive dis- charge of exhaust gases. Overall, the turbocharger is said to be the most efficient ever produced by EMD. The state-of-the-art G turbo- charger provides a 15-percent in- crease in air flow for reduced ther- mal loading of critical engine com- ponents. This higher air flow, com- bined with an increased injection rate from the new 0.56-inch plunger injector, accounts for the increase in fuel economy at rated output, with no increase in engine thermal load- ing. A key concern in the development of a large-displacement diesel is reli- ability. Throughout the develop- ment of the 710G, EMD used ad- vanced laboratory techniques to analyze stress and predict perfor- mance. Finite element analysis and comprehensive strain-guage testing were used extensively to take full advantage of EMD's broad experi- ence with the 645 engines. Total development cost of the 710G was $60 million, and the tooling cost alone was $78 million. GARDNER Circle 22 on Reader Service Card The first-ever intercooled Gard- ner diesel engine was introduced to the marine market early this year in London. The manufacturer, L. Gardner & Sons Limited, is a Hawk- er Siddeley company. Designated the 6LYTi, the new engine is available in power ratings of 335 bhp at 1,700 rpm or 310 bhp at 1,600 rpm for propulsion duties, and 230 to 280 kva at 50 cycles for auxiliary duties. A logical develop- ment from the turbocharged 6LYT, the 15.5-liter intercooled engine has the highest power-to-weight ratio and fuel efficiency of any Gardner engine, yet the new model remains lightly stressed and has capacity for future development. The 6LYTi engine shares the main features of the 6LYT, includ- ing cross-flow cylinder head, oil jet piston cooling, single-piece cam- shaft, externally mounted viscous damper, and a rear-mounted gear train. Intercooling is provided by an air- to-water tubular design intercooler that is included in the closed-circuit freshwater cooling system of the en- gine. This system is suitable for combining with an externally mounted heat exchanger or keel cooling. Complete with a shallow case marine gearbox, the new 6LYTi weighs only 3,510 pounds. The first production units of the 6LYTi intercooled marine engines will be fitted with Twin Disc re- verse/reduction gears, although gears from other manufacturers will be available as options. As with all Gardner engines, the new unit is approved by the American Bureau of Shipping, Det norske Veritas, and Lloyd's Register of Shipping. Product literature and technical reports are available free of charge from the manufacturers included in this review. Just cir- cle the appropriate Reader Ser- vice number(s) on the postpaid card in the back of this issue. 22 Maritime Reporter/Engineering News
