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DURING ENGINE DYNO durability testing of oxidation catalysts, manganese deposition on the catalyst hot faces sufficient to affect catalyst performance for HC and CO conversions was observed. The severity of the problem is related to the MMT level in the fuel, the cell density of the catalyst's monolithic support, and engine aging time. The nature of manganese deposition in these studies and how it affects catalyst performance is explored. Apart from the MMT phenomenon, comparative studies of oxidation catalysts on conventional ceramic and high cell density, thin-wall metallic supports indicate that the latter offer significantly improved HC conversion durability.

The antenna test engineer, by defining his basic needs and utilizing relatively uncomplicated measurement techniques, can easily define the performance of most vehicle antenna designs. Employing basic “off-the-shelf” instruments and an uncomplicated test site approach, the cost of the test range can be minimized while retaining maximum versatility. Due to the phenomenal growth and interest in Citizens Band (CB), measurement techniques for CB will be emphasized along with AM and FM bands.

A new 40-channel CB Radio System has been developed by a major automotive manufacturer as a regular production option for a number of its 1978 cars and trucks. To maximize theft resistance, the system uses a remote chassis, detachable microphone, and a tri-band antenna. The factory-installed CB features a uniquely styled power microphone, digital channel display, automatic scan, switchable noise blanker, memory for emergency channel 9, automatic noise limiter, and extensive vehicle noise suppression. Vehicle speaker(s) are time-shared with the entertainment system. This state-of-the-art system is presented here in terms of component functions, design development, manufacture, and test equipment and procedures.

This paper discusses the relative effects of transmitter power, antenna efficiency, and interference from local and distant stations on the communicating range of a mobile CB station. Performance comparisons between several popular antenna types and curves of signal strength versus distance are included.

Application of dedicated microprocessor controlled and frequency synthesized AM-FM electronic tuning with digital display and unique push button keyboard control in an automotive radio. Presentation of the human engineering, technical aspects and benefits of an all electronic approach. Description of the modular design of the finished radio and application of computerized testing.

Electronic tuning and frequency synthesis techniques have made possible the combination of an eight-track tape player, digital clock and AM/FM/Stereo/Signal-Seeking automobile radio in a 2700 cm3 package. Phase-locked-loop circuitry, varactor tuning, and calculator logic replace the conventional mechanical tuner and provide all its functions. In addition to reducing receiver weight, this tuning technique assures extreme tuning accuracy and frequency stability.

The use of electronic digital tuning in automobile radios offers many advantages. These include radios of reduced size and weight which are becoming all important considerations in the design of all automotive components. In addition, the reduced size allows considerable freedom for interior stylists. At the same time, electronically tuned radios offer superior performance at reduced cost. This paper demonstrates the probability that in the near future nearly all automobile radios will be digitally tuned. It provides a direct comparison between presently available radios and all-electronic radios.

A study has been made of the influence of press forming and corrosion under cars on the fatigue properties of sheet steels. Press forming was done in the laboratory and corresponded to types of deformation occurring in production. Samples from laboratory and undervehicle corrosion environments were tested. Forming was found to improve fatigue properties and corrosion to cause a deterioration. The drop in fatigue strength caused by corrosion was similar for all types of steel examined, and no worse than that caused by moderate notches that are commonly encountered in service.

This paper examines the effect of hot dip galvanizing on the fatigue resistance of SAE 950X HSLA steels. Tensile and constant amplitude strain-controlled fatigue data for 0.123 in. gage galvanized steel are compared to data from three uncoated SAE 950X steels. Additionally, results of testing galvanized and uncoated 0.103 in. gage MAXI-FORM® 50 (SAE 950X) steel from a split coil are compared. Galvanizing produced essentially no changes in tensile or fatigue properties except in the extreme low-cycle fatigue regime where galvanizing caused a reduction in the fatigue ductility coefficient, εf́.

Measured values of velocity and associated turbulence properties have been obtained in a motored single-cylinder Diesel engine and in a plexiglass simulation engine. The quality of the signals obtained from thereal engine and the corresponding useful data rate are quantified and discussed. As a consequence, it is shown that measurements in real engines are likely to relate to crank-angle intervals of the order of 10 degrees. The implications of this conclusion are quantified by analysis and by measurements in the plexiglass engine. The results, from the motored Diesel engine, also show that values of velocity cannot be measured throughout the cylinder cavity.

Three dimensional velocity measurements of the in-cylinder aerodynamics in the steady airflow rig for two different Diesel cylinder heads were obtained by laser anemometry. Complex recirculating flows with high mean velocity gradients were found while the fluctuating component of velocity was relatively constant. Vector addition of two components in turn allowed rapid comparison to be made of the airflow characteristics between cylinder heads and and comparison with earlier hot wire and vane anemometer measurements. The directed port cylinder head was found to produce two main vortices whereas a cast helical port produced a flow which approached simple solid body rotation.

During the engineering and public demonstration testing phases of the Transbus Program, the three prototype coaches equipped with gas turbine powerplants exhibited some advantageous operational characteristics that warranted further investigation. Consequently, Booz, Allen Applied Research investigated the gas turbine engine as a potential power source for transit coaches. An in-depth survey was conducted of gas turbine engine manufacturers, whose products may be suitable for transit coaches, to determine their merits as compared to those of the diesel engine. Only Detroit Diesel Allison Division (DDAD) has a product sufficiently developed to warrant serious consideration of volume production. This investigation indicates that while current engines are not economically justifiable, the gas turbine engine may be potentially superior to the diesel.

This paper describes recent trends in transit bus design in the United States and Western Europe. It discusses the basic legal, regulatory, and operational constraints that historically have guided the design of full-size transit buses. It specifically addresses the implications of the constraint that fare payment must occur on-board the transit bus and be monitored by the driver. Future bus design concepts are presented which demonstrate the improvements that would be possible in service characteristics if this constraint were removed. The material presented is based in part upon research conducted for the Urban Mass Transportation Administration on the impact of fare collection on transit bus design.

The automotive industry is constantly faced with the challenge of satisfying consumer desires on one hand and complying with government regulations on the other hand. These requirements, when reduced to design parameters, require many design trade-offs. This paper presents a package of new design engineering ideas which can adequately meet this challenge and require very few design trade-offs. The paper begins by pointing out that the reliability, maintainability, safety, and human factor (RMSH) considerations in design stages are the basis for meeting this challenge. Then five essential elements of the RMSH considerations in design process are discussed.

This paper describes a new leveling system which addresses itself to the needs of future, lighter weight vehicles for which attitude control is more important and engine vacuum is partly or totally unavailable. The system utilizes reverse air flow to clean its filter and regenerate its air dryer for lifetime moisture control. The electronic controller and high capacity compressor provide positive response without the use of a storage tank. The reduced number of air fittings and an improved “snap-on” fitting help guard against leaks. This system is described as it interfaces with passenger cars and light trucks using air-adjustable springs in the suspension system.

New hydropneumatic levelling systems with single and twin chambers are presented for application in almost all vehicle makes and types. They are self-energizing and convert the relative movement between axle and body to the advantage of height adjustment. The internal pump work must be understood as load dependent damping, optimizing the settings in relation to load-dependent gas spring rates. It is shown that the units can be designed for similar body frequency within a wide range of payloads. This essay will assist in solving the problems of soft vehicle suspensions with large load differences.

Soft suspension springs are an essential requirement to absorb irregularities in road surfaces without transmitting excessive acceleration forces to the vehicle. Passive attitude control systems compensate for suspension height changes due to static load variations but leave a problem of excessive body motion in response to lateral and longitudinal acceleration. In this paper a system of active ride is described which retains the advantages of a soft suspension, yet controls body pitch and roll due to braking and cornering forces. Handling quality is enhanced by precise control of front to rear roll stiffness. Computed and experimental data is presented to establish fulfilment of the design objectives.

One class of ceramic materials that is being considered for application in diesel environment is the densified silicon carbide. The composition, microstructure, physical and mechanical properties of several members of this family of materials will be discussed along with illustrations of the current state of the art of component complexity.

A procedure to analyze and design adiabatic diesel engine components is developed. The analytical basis for the procedure is presented. An experimental study of related thermal boundary conditions in the combustion chamber is conducted. Mean effective gas temperatures as high as 2200°F are measured. A new adiabatic diesel piston, using a ceramic top, is designed and demonstrated using the procedure. Initial engine testing of the piston is encouraging, with full design power being achieved. The piston is considered the critical component in the overall development of an adiabatic diesel engine.

Some truck equipment manufacturers now offer a “Major Overhaul Program” to the users of digger derrick trucks. This program involves a complete tear down of the existing equipment and body; the rebuilding and remounting of the unit on a new truck chassis. This is followed by complete testing and finish work. The results produce a digger derrick truck in mint condition, under warranty, at a considerable savings when compared to a new unit.