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The recent introduction of lower compression ratio engines and the concurrent marketing of unleaded and low-lead content gasolines of generally lower octane number made it appropriate to investigate the interrelationships of engine performance and gasoline octane quality using the “new” engines and fuels. Programs were carried out to compare fuel economy and acceleration performance of eight matched pairs of 1970 and 1971 automobiles. In addition, octane requirements were obtained on 43 1971 cars with 3,000-12,000 deposit miles. A total of 146 unleaded, low-lead, and leaded regular gasolines obtained at service stations throughout the country were analyzed, and the road octane performance of these gasolines was determined using 1970 and 1971 cars designed for regular gasoline.

Since 1978 Ford Motor Company has been surveying the fuel economy of employes who lease new light duty vehicles from the Company. Winter and summer survey data for the three years are analyzed and compared. Car results show a significant and steady increase in average on-road fuel economy over the three year period. The percent differential between EPA measured and actual on-road fuel economy has lessened substantially since 1978. Furthermore, the percent difference between EPA and on-road is essentially constant over the range of EPA values for each of the three years. Limited fuel economy results for 1980 trucks are also discussed.

A program of emission testing and carburetor adjustment to reduce the levels of hydrocarbons and carbon monoxide in the exhaust gases and to demonstrate fuel economy improvements was held in Charlottetown during the week of July 14 to 19, 1980. The program was a co-operative effort of the Centre of Energy Studies of the Technical University of Nova Scotia, the Mobile Sources Division of the Air Pollution Control Directorate, Environment Canada and the Prince Edward Island Energy Corporation. Five hundred and twenty vehicles were tested during the period. The program was well received by the public and indicated that only 32% of the vehicle fleet were within specification when initially tested. A large percentage of these vehicles were satisfactorily adjusted. Mailback record cards were used to obtain an indication of the improved fuel economy. The data suggests that a substantial saving in fuel can be attained through carburetor tuning for low exhaust emissions.

The demand for improved fuel economy in both cars and trucks has emphasized the need for lighter weight components. The application of high strength steel to wheels, both rim and disc, represents a significant opportunity for the automotive industry. This paper discusses the Ranger HSLA wheel program that achieved a 9.7 lbs. per vehicle weight savings relative to a plain carbon steel wheel of the same design. It describes the Ranger wheel specifications, the material selection, the metallurgical considerations of applying HSLA to wheels, and HSLA arc and flash butt welding. The Ranger wheel design and the development of the manufacturing process is discussed, including design modifications to accommodate the lighter gage. The results demonstrate that wheels can be successfully manufactured from low sulfur 60XK HSLA steel in a conventional high volume process (stamped disc and rolled rim) to meet all wheel performance requirements and achieve a significant weight reduction.

General Motors Powertrain Division has developed the next generation big block V8 engine for introduction in the 1996 model year. In addition to meeting tighter emission and on-board diagnostic legislation, this engine evolved to meet both customer requirements and competitive challenges. Starting with the proven dependability of the time tested big block V8, goals were set to substantially increase the power, torque, fuel economy and overall pleaseability of GM's large load capacity gasoline engine. The need for this new engine to meet packaging requirements in many vehicle platforms, both truck and OEM, as well as a requirement for minimal additional heat rejection over the engine being replaced, placed additional constraints on the design.

General Motors Powertrain Group (GMPTG) has developed an all new small block V8 engine, designated LS1, for introduction into the 1997 Corvette. This engine was designed to meet both customer requirements and competitive challenges while also meeting the ever increasing legislated requirements of emissions and fuel economy. This 5.7L V8 provides increased power and torque while delivering higher fuel economy. In addition, improvements in both QRD and NVH characteristics were made while meeting packaging constraints and achieving significant mass reductions.

As part of the 1997 Propane Vehicle Challenge, a team of twelve UTEP students converted a 1996 Dodge Grand Caravan with a 3.3 L V6 engine to dedicated Liquefied Petroleum Gas (LPG) operation according to the 1997 Propane Vehicle Challenge (PVC) competition rules (16). The 1997 UTEP team developed an LPG liquid phase port fuel injection (LPP-FI) system for the minivan. The UTEP design strategy combines simplicity and sound engineering practices with the effective use of heat resistant materials to maintain the LPG in the liquid phase at temperatures encountered in the fuel delivery system. The team identified two options for fuel storage with in-tank fuel pumps. The competition vehicle incorporates a five-manifold eight inch diameter Sleegers Engineering LPG tank fitted with a Walbro LPTS in-tank pump system, providing a calculated range of 310 city miles and 438 highway miles.

A student team from Minnesota State University, Mankato's Automotive Engineering Technology program entered the Clean Snowmobile Challenge 2000. A 1998 Polaris Indy Trail was converted to indirect fuel injection running on a computer controlled closed loop fuel system. Also chassis, exhaust, and hood design modifications were made. The snowmobile was designed to compete in eight events. These events included acceleration, emissions, hill climb, cold start, noise, fuel economy/range, handling/driveability, and static display. The snowmobile modifications involved every aspect of the snowmobile with special emphasis on emissions and noise. Laboratory testing led to the final design. This paper details the modifications and test results.

The Injection Rate Shaping consists in a novel injection strategy to control air-fuel mixing quality via a suitable variation of injection timing that affects the injection rate profile. This strategy has already provided to be useful to increase combustion efficiency and reduce pollutant emissions in the modern compression ignition engines fed with fossil Diesel fuel. But nowadays, the ever more rigorous emission targets are enhancing a search for alternative fuels and/or new blends to replace conventional ones, leading, in turn, a change in the air-fuel mixture formation. In this work, a 1D model of spray injection aims to investigate the combined effects of both Injection Rate Shaping and alternative fuels on the air-fuel mixture formation in a compression ignition engine. In a first step, a ready-made model for conventional injection strategies has been set up for the Injection Rate Shaping.

The in-cylinder direct injection of fuels can be a further step towards cleaner and more efficient internal combustion engines. However, the injector design and its characterization, both experimental and from numerical simulation require accurate diagnostics and efficient models. This work aims to simulate the complex behavior of the gaseous and liquid jets through an outwardly opening injector characterized by optical diagnostics using a one-dimensional model without using three dimensional models. The behavior of the jet from an outwardly opening injector changes according to the type of fuel. In the case of the gas, the experimental investigations put in evidence three main jet regions: 1) near-field region where the jet shows a complex gas-dynamic structure; 2) transition region characterized by intense mixing; 3) far-field region characterized by a fully developed subsonic turbulent jet.

Zero-dimensional, one-dimensional, and quasi-dimensional models for simulation of SI and CI engines with respect to: engine breathing and boosting; SI combustion and emissions; CI combustion and emissions; fundamentals of engine thermodynamics; thermal management; mechanical and lubrication systems; system level models for controls; system level models for vehicle fuel economy and emissions predictions. Presenter Fabio Bozza, Universita di Napoli

In this work an integration between a 1D code (Gasdyn) with a CFD code (OpenFOAM®) has been applied to improve the performance of a Moto3 engine. The four-stroke, single cylinder S.I. engine was modeled, in order to predict the wave motion in the intake and exhaust systems and to study how it affects the cylinder gas exchange process. The engine considered was characterized by having an air induction system with integrated filter cartridge, air-box and intake runner, including two fuel injectors, resulting in a complex air-path from the intake mouth to the intake valves, which presents critical aspects when a 1D modeling is addressed. The exhaust and intake systems have been optimized form the point of view of the wave action. However, due to the high revolution speed reached by this type of engine, the interaction between the gas stream and the fuel spray becomes a key aspect to be addressed in order to achieve the best performance at the desired operating condition.

Recently, society has demanded better performance from motorcycle regarding comfort, fuel economy, exhaust emission, and safety, in addition to traditional performance indicators. In the development of power trains, therefore, compact and lightweight hardware with improved transmission efficiency has been introduced, along with system technologies that optimize the engine revolution speed range and reduction ratio to suit driving conditions. This approach focuses on improving overall efficiency and addressing the issues of easier drivability and greater active safety. Electronic Controlled Continuously Variable Transmission (ECCVT) with high transmission efficiency is characterized by a Dry Hybrid Belt, in addition to an electronic controlled DC motor-driven shift mechanism, and an Electronic Controlled wet multi-plates Clutch (ECC).

This paper describes new 2 stroke fuel injected spark ignition outboard motor equipped with unique oxygen sensor feed back control system to assure constantly optimized air/fuel ratio. First, the general concept and the engineering target of commercial model are explained, and then the design and arrangement of oxygen sensor feedback fuel injection control system are described. Common automotive oxygen sensor is utilized in this system, and it is devised to overcome the problems inherent in 2-stroke engines. This paper also describes the controlled combustion system that enhances consistent and stable performance, and improves fuel efficiency. Applying these technologies, 40% less fuel consumption in cruise range was demonstrated by the comparative test with conventional fuel injected 2-stroke model.

Although in-cylinder optical diagnostics have provided significant understanding of conventional diesel combustion, most alternative combustion strategies have not yet been explored to the same extent. In an effort to build the knowledge base for alternative low-temperature combustion strategies, this paper presents a comparison of three alternative low-temperature combustion strategies to two high-temperature conventional diesel combustion conditions. The baseline conditions, representative of conventional high-temperature diesel combustion, have either a short or a long ignition delay. The other three conditions are representative of some alternative combustion strategies, employing significant charge-gas dilution along with either early or late fuel injection, or a combination of both (double-injection).

To measure the fuel vapor concentration in an unsteady evaporating spray injected into nitrogen atmosphere, the exciplex-forming method, which produces spectrally separated fluorescence from the liquid and vapor phase, was applied in this study. Two experiments were conducted to investigate the qualitative and quantitative applicability of the technique in a high temperature and high pressure atmosphere during the fuel injection period. One is to examine the thermal decomposition of TMPD dopant at a high temperature and a high pressure nitrogen atmosphere during a short period of time. The other is to calibrate the relationship between fluorescence intensity and vapor concentration of TMPD at different vapor temperatures. And then, the qualitative measurement of fuel vapor concentration distributions in diesel sprays was made by applying the technique.

Cross-sectional distributions of the liquid phase temperatures in fuel sprays were measured using a laser-induced fluorescence technique. The liquid fuel (n-hexadecane or squalane) was doped with pyrene(C16H10). The fluorescence intensity ratios of the pyrene monomer and excimer emissions has temperature dependence, and were used to determine the liquid phase temperatures in the fuel sprays. The measurements were performed on two kinds of sprays. One was performed on pre-heated fuel sprays injected into surrounding gas at atmospheric conditions. The other was performed on fuel sprays exposed to hot gas flow. The spray was excited by laser radiation at 266nm, and the resulting fluorescence was imaged by an intensified CCD camera. The cross-sectional distribution of the liquid phase temperature was estimated from the fluorescence image by the temperature dependence of the intensity ratio.

A sheet of laser light from a frequency-doubled Nd-YAG laser (λ = 532 nm) approximately 150 μm thick is shone through the cylinder of a single cylinder internal combustion engine. The light scattered by the fuel spray is collected through a quartz window in the cylinder and is imaged on a 100 × 100 diode array camera. The signal from the diode array is then sent to a microcomputer for background subtraction and image enhancement. The laser pulse is synchronized with the crank shaft of the engine so that a picture of the spray distribution within the engine at different times during injection and the penetration and development of the spray may be observed. The extent of the spray at different positions within the chamber is determined by varying the position and angle of the laser sheet with respect to the piston and the injector.

THE development of the two-stage torque converter with automatic double clutch is presented here. The author covers particularly the substitution of casting for fabrication for several of the units in the transmission.

2-step variable valve actuation using early-intake valve closing is a strategy for high fuel economy on spark-ignited gasoline engines. Two discrete valve-lift profiles are used with continuously variable cam phasing. 2-step VVA systems are attractive because of their low cost/benefit, relative simplicity, and ease-of-packaging on new and existing engines. A 2-step VVA system was designed and integrated on a 4-valve-per-cylinder 4.2L line-6 engine. Simulation tools were used to develop valve lift profiles for high fuel economy and low NOx emissions. The intake lift profiles had equal lift for both valves and were designed for high airflow & residual capacity in order to minimize valvetrain switching during the EPA drive cycle. It was determined that an enhanced combustion system was needed to maximize fuel economy benefit with the selected valve lift profiles. A flow-efficient chamber mask was developed to increase in-cylinder tumble motion and combustion rates.