Search Results

Current technology, especially in our dynamic industry, demands more reliable and up-to-date information in order to operate efficiently. Data of many kinds, from many sources, must be collected, analyzed, and rapidly transmitted into information which can be used to optimize performance and improve our product. To meet these needs in production diesel engine testing, a process control system has been developed around the basic objective of establishing an accurate and regimented test program, which will provide more reliable information for analysis and action, increased test capacity, accurate history data, and a higher quality product. This paper describes the basic design of such a system, the advantages to be gained, and the overall operation.

Product design cycle time can be significantly reduced with the utilization of Computer Aided Engineering. (CAE) techniques. Computer modeling and analyses can eliminate portions of the lengthy procedure required by traditionally accepted Product Development Methods. This paper examines and compares a CAE application to a conventional method in the redesign of a structural component of a heavy-duty truck. The procedures to achieve design objectives: Modeling through stress analysis iterations and verification of analyses by prototype testing will be addressed together with the impact of such approach on cost and quality of engineering.

The truck flywheel power takeoff has proven itself as a reliable means of supplying continuous power to a variety of mounted equipment. The features of available units are described in detail in an effort to provide the design and application engineer with complete information regarding their function and application, and to stimulate expanded usage of this constant power source.

In an ongoing effort to further improve engine durability, effects on ring wear of various engine operating variables were measured utilizing a radioactive wear test, Due to findings in this wear testing, developments were initiated in air filtration, fluid filtration and oil quality level. Implementation of these changes has improved engine durability.

Mack Trucks' E7 direct injection heavy-duty diesel engine is a four cycle, in-line six cylinder design. The 728 cu in. (12 1) engine is turbocharged and chassis mounted air-to-air aftercooled. The E7 is being introduced in 1989 with power ratings of 250 hp to 400 hp (186 kW to 298 kW) at 1700 to 1800 rpm, calibrated to 1990 EPA standards. Highlights of the E7 engine's design, development and performance are presented. Information is included which illustrates the strategies utilized to attain program goals of controlling weight and cost while extending power ratings, reducing emissions levels, and improving fuel economy, serviceability, durability and reliability.

A new 998 CID V8 engine series has been developed by Mack Trucks, Inc. to supplement its line of heavy duty diesel engines. These engines, the E9 Series, are available in two configurations--a 400 bhp (298 kW) high torque rise version and a 440 bhp (328 kW) conventional torque backup version. Increased horsepower and improved fuel economy were achieved through the development of a chassis mounted charge air cooler and a new four-valve cylinder head. In addition, significant durability improvements were obtained due to the reduced thermal loadings resulting from the lower charge air temperatures. Additional noteworthy features include a new injection pump, improved lube oil system, advanced piston design, and proper selection of seals and gasket materials.

Mack Trucks design and analysis capabilities have enhanced considerably with in-house computer aided engineering (CAE) systems. The CAE system includes Solids and 3-D Geometric Modeling, Graphic Finite Element Model Generator and general purpose Finite Element Analysis software. Finite element analysis of the cast Transverse Torque Rod Bracket was done as a product improvement to the existing fabricated design. Correlation of the Finite Element results with experimental stress analysis results for the proposed design was achieved to confirm the analysis procedure. Improved structural strength and substantial weight and cost reduction over the existing design was achieved with significant reduction in design cycle time.

Progression of the successful engine program exemplified by the Mack ENDT675 Maxidyne Six, having an essentially constant horsepower characteristic in the operating speed range, has led to the development and production of the new Mack ENDT865, Maxidyne V-8 having similarly ordered performance at higher output. Significant advances in design to maintain reliability at high loadings including a new injection pump, a simplified oil system, and a single turbocharger arrangement are discussed, as well as a new integral engine brake. The Mack Dynatard Engine Brake is specifically covered in the second part of this paper.