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AS a basis for the analyses of this symposium, a hypothetical car has been used to evaluate the engine power distribution in performance. Effects of fuel,-engine accessories, and certain car accessories are evaluated. The role of the transmission in making engine power useful at normal car speeds is also discussed. Variables encountered in wind and rolling resistance determinations are reevaluated by improved test techniques. Net horsepower of the car in terms of acceleration, passing ability and grade capability are also summarized.

The principles of combustion in a spark ignition engine are discussed. Engine processes and reactions are explained as to the manner in which they influence exhaust composition. The subject is approached by considering how chemical phenomena interact in a complex system such as a spark ignition engine. Special attention is given to the effect on exhaust composition of such factors as engine design and modifications, fuel composition, and engine maintenance.

The flow field contained within ten planes inside a cylinder of a 3.5 liter, 24-valve, V-6 engine was mapped using a three-dimensional Laser Doppler Velocimetry (3-D LDV) system. A total of 1,548 LDV measurement locations were used to construct the time history of the in-cylinder flow fields during the intake and compression strokes. The measurements began during the intake stroke at a crank angle of 60° ATDC and continued until approximately 280° ATDC. The ensemble averaged LDV measurements allowed for a quantitative analysis of the dynamic in-cylinder flow process in terms of tumble and swirl motions. Both of these quantities were calculated at every 1.8 crank degrees during the described measurement interval. Tumble calculations were performed about axes in multiple planes in both the Cartesian directions perpendicular to the plane of the piston top. Swirl calculations were also accomplished in multiple planes that lie parallel to the plane of the piston top.

This paper discusses simplified lumped parameter thermal modeling of power train components. In particular, it discusses the tradeoff between model complexity and the ability to correlate the predicted temperatures and flow rates with measured data. The benefits and problems associated with using a three lumped mass model are explained and the value of this simpler model is promoted. The process for correlation and optimization using modern software tools is explained. Examples of models for engines and transmissions are illustrated along with their predictive abilities over typical driving cycles.

PLYMOUTH'S new V-8 engine has a specific output of 0.65 bhp/cu in. and 145-psi bmep — obtained through a combination of high thermal, volumetric, and mechanical efficiencies. Good design, the author points out, has achieved this high output despite the dual-venturi carburetor and the 7.6/1 compression ratio, selected for satisfactory operation on regular-grade fuels. The engine has a bore and stroke of 3.563 × 3¼, weighs 568 lb without flywheel, is 29⅜ in. long, and is designed for optimum response to future compression ratio increases. (A report of oral discussion following presentation of this paper appears on p. 220, following “The New Packard V-8 Engine,” by W. E. Schwieder.)

A new tool for analyzing transmissions that use planetary gearsets is presented. With this tool, entire transmissions are usually represented by a single lever, and the calculation of most characteristics is as simple as summing moments of a lever. A miniature cookbook of levers, for various planetary arrangements is included which can be helpful in selecting a planetary to achieve the desired objectives of a user.

Formula One motorsport competition, ever seeking increases in powertrain responsiveness and efficiency, has utilized electronically-shifted manual transmissions for nearly a decade. With the advent of this technology for passenger car usage ( for example the Magneti Marelli “Selespeed” system), new levels of powertrain electronic control become possible. At the same time, world-wide emission and fuel economy standards have driven powertrain designers to seek transmissions that are multi-faceted; able to offer manual transmission levels of driveline efficiency while simultaneously offering the ability to be automatically controlled. This paper will document a 1995-1996 Chrysler advanced powertrain concept study that culminated in a fully driveable, fully automatic, manual 5 speed transmission Neon coupe.

THE design and construction of the PowerFlite automatic transmission are described by the authors. It is of the torque converter type, some models being water-cooled, while others are direct air cooled. Details of the hydraulic controls are explained, including the one-piece shift valve and the shuttle valve for controlling closed-throttle shifts. It is claimed that this transmission has relative simplicity, light weight, and smoothness of operation.

Most of the current fuel supply specifications, including the key parameters in the transient fuel control strategies, are experimentally determined since the complexity of multiphase fuel flow behavior inside the intake manifold is still not quantitatively understood. Optimizing these specifications, especially the parameters in transient fueling systems, is a key issue in improving fuel efficiency and reducing exhaust emissions. In this paper, a model of fuel spray, wall-film flow and wall-film vaporization has been developed to gain a better understanding of the multiphase fuel-flow behavior within the intake manifold which may help to determine the fuel supply specifications in a multi-point injection system.

A torque converter lock-up clutch was introduced by Chrysler Corporation in a majority of its passenger cars in the 1978 model year. The lock-up clutch improves fuel economy by eliminating torque converter slip in direct gear above a predetermined speed. The clutch and its controls were designed to fit within the confines of the existing transmission. The development of the clutch was primarily concerned with achieving adequate endurance life, good shift quality and isolation of torsional vibrations.

THIS paper discusses the progress of research on the automotive gas turbine and predicts its future potentialities. Comparison of gas turbines and presently used engines shows the possibilities of the gas-turbine applications. Design, construction, and testing of gas turbines are discussed, especially in the light of economy and performance.

The low noise and linear sound level characteristics of passenger vehicles are receiving increased scrutiny from automotive journalists. A linear noise level rise with increasing engine rpm is the first basic aspect of insuring an acceptable vehicle interior engine noise sound quality. In a typical case of structural response to engine vibration input, interior noise begins to rise with rpm, remains constant or even drops as the engine continues to accelerate, and then exhibits a noise period corresponding to the structure's natural frequency. Frequently this nonlinearity is bothersome to the customer. During the development process, Chrysler's Dodge and Plymouth Neon exhibited just such a nonlinear rise in noise level, heard within the passenger compartment, when the vehicle was accelerated through 4200 rpm.

THE GRADEABILITY formula can be used as the basic means for rating a truck transmission. By correlating the gradeabilities in the various gear ratios with a highway requirement probability curve, the per cent of time in each ratio can be obtained. The required hours of gear life for each ratio are then determined, and compared with the available gear life in the ratios. This procedure gives a detailed analysis of a transmission rating for one vehicle specification at a specified mileage between overhauls. A limitation of the system is that it cannot be applied quickly to various vehicle specifications. The paper outlines the method for constructing a nomogram to overcome this.*

To understand how the passenger compartment cavity interacts with the surrounding panels (roof, windshield, dash panel, etc) a numerical panel contribution analysis was performed using FEA and BEA techniques. An experimental panel contribution analysis was conducted by Reiter Automotive Systems. Test results showed good correlation with the simulation results. After gaining some insight into panel contributions for power train noise, an attempt was made to introduce beads in panels to reduce vibration levels. A fully trimmed body structural-acoustic FEA model was used in this analysis. A network of massless beam elements was created in the model. This full structural-acoustic FEA model was then used to determine the optimal location for the beads, using the added beams as optimization variables.

Most United States vehicle assembly plants produce significantly more automatic transmission equipped vehicles than manual transmission vehicles. Assembling these two vehicles on a common production line can create complexity problems. This paper describes the design and development of a pre-assembled manual transmission clutch and flywheel modular assembly which reduces most of these problems. This assembly is used on the 1993 model year mini-van with a 2.5L four cylinder engine. This modular clutch system utilizes the same starter ring gear carrier (driveplate) used on automatic transmission equipped vehicles. It pilots into the crankshaft similar to the automatic transmission torque converter. It is balanced as an assembly which results in a lower system imbalance. A significant system piece cost saving, in comparison with today's competitive market, was achieved.

Natural gas-fueled vehicles impose unique requirements on exhaust aftertreatment systems. Methane conversion, which is very difficult for conventional automotive catalysts, may be required, depending on future regulatory directions. Three-way converter operating windows for simultaneous conversion of HC, CO, and NOx are considerably more narrow with gas engine exhaust. While several studies have demonstrated acceptable fresh converter performance, aged performance remains a concern. This paper presents the results of a durability study of eight catalytic converters specifically developed for natural gas engines. The converters were aged for 300 hours on a natural gas-fueled 7.0L Chevrolet engine operated at net stoichiometry. Catalyst performance was evaluated using both air/fuel traverse engine tests and FTP vehicle tests. Durability cycle severity and a comparison of results for engine and vehicle tests are discussed.

A Methanol Concentration Smart Sensor has been developed to support the demand for alternately fueled vehicles operating on blends of methanol and gasoline in any mixture up to 85% methanol. The sensor measures concentration by exploiting the difference in dielectric properties between methanol and gasoline. The measurement is made based on the distributed capacitance of a coil of wire, contained in a reservoir through which the fuel passes. This signal, along with temperature compensation inputs, is then fed to an integral microprocessor, which provides a voltage output proportional to the methanol concentration of the fuel. The Powertrain Controller uses this information to modify injector pulse width and provide proper spark advance. This paper will explain the sensor's development methodology and function.

Environmental issues have significantly impacted automotive operations worldwide. Countries are continuing to ratchet down their allowable emissions and to remain competitive, all industries must take Life Cycle Management (LCM) and implement it into everyday practice. Economic competitiveness as a part of economic development is central to the nation's social and financial well-being. America must catch-up to the rest of the world in how it views government and industry relationships as well as how to focus costs within the corporate structure. The adversarial relationships between government and industry must give way to stronger partnerships. For this concept to succeed a long term view of problems must be made by a corporation and both short and long term actions taken to resolve these problems. Industry must help create the market for recycled goods and must “walk the talk” by using recycled goods where possible.

The UBHC emissions during cold starting need to be controlled in order to meet the future stringent standards. This requires a better understanding of the characteristics of the time resolved UBHC signal measured by a high frequency FID and its phasing with respect to the valve events. The computer program supplied with the instrument and currently used to compute the phase shift has many uncertainties due to the unsteady nature of engine operation during starting. A new technique is developed to measure the in-situ phase shift of the UBHC signal under the transient thermodynamic and dynamic conditions of the engine. The UBHC concentration is measured at two locations in the exhaust manifold of one cylinder in a multicylinder port injected gasoline engine. The two locations are 77 mm apart. The downstream probe is positioned opposite to a solenoid-operated injector which delivers a gaseous jet of hydrocarbon-free nitrogen upon command.