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Recent industry trends have resulted in growing interest among automakers in low to medium volume manufacturing. The expansion of automobile production into developing economies and the desire to produce specialized vehicles for niche markets have pressed the automakers to find cost effective solutions for manufacturing at low volumes, particularly with regard to sheet metal forming. Conventional high volume stamping operations rely heavily on achieving minimum scale economies which occur at about 200,000 parts per year. These scale economies are mainly dictated by the efficient use of the standard, expensive cast iron dies. These dies can cost well over one million dollars depending on the part, and in return offer tool lives over 5 million strokes. Die investment can be reduced by changing the stamping process technology. Hydro-mechanical forming has been proposed as a promising low volume alternative to conventional stamping.

Intake valve thermal behavior was observed across a wide range of operating conditions while running an engine on both propane and gasoline. Compared to the gaseous fuel, the liquid fuel operation has cooler valve temperatures (∼50-100C difference) and there is significant temperature gradient across the valve surface due to liquid fuel impinging on the front quadrant of the valve. The valve warm-up time is largely determined by the effective thermal inertia of the valve (∼valve body plus 1/3 of stem mass) and the thermal resistance to the seat. The valve is heated up by the combustion chamber; the dominant cooling paths are through the seat contact and the liquid fuel evaporation. Just after starting, very little fuel evaporates from the cold valve until there is a substantial increase in valve temperature in a period of approximately 10-20 seconds.

This paper reports attempts to gain better understanding of the influence of bearing wear on the performance of hydrodynamically lubricated bearings. An analysis was carried out on bearings from a Sapphire bearing test rig using an elastohydrodynamic model. This involved the use of both the original and worn bearing surface profiles. The results indicated that bearing wear could improve the lubrication conditions. Also the progress of wear in the bearing was simulated using a simple model of the wear process. This model predicted that the wear would progress at a reducing rate. The predicted wear agreed well with measurements both in terms of the wear profile and the location of wear.

The possibility of predicting engine bearing durability by elastohydrodynamic lubrication (EHL) calculations was investigated with the aim of being able to improve durability efficiently without conducting numerous confirmation tests. This study focused on the connecting rod big-end bearing of an automotive engine. The mechanisms of wear and fatigue, which determine bearing durability, were estimated by comparing the results of EHL analysis and experimental data. This comparison showed the possibility of predicting the wear amount and the occurrence of fatigue by calculation.

In a recent paper (Hoult & Meador, [1]) a novel method of estimating the costs of parts, and assemblies of parts, was presented. This paper proposed that the metric for increments of cost was the function log (dimension/tolerance). Although such log functions have a history,given in [1], starting with Boltzman and Shannon, it is curious that it arises in cost models. In particular, the thermodynamic basis of information theory, given by Shannon [2], seems quite implausible in the present context. In [1], we called the cost theory “Complexity Theory”, mainly to distinguish it from information theory. A major purpose of the present paper is to present a rigorous argument of how the log function arises in the present context. It happens that the agrument hinges on two key issues: properties of the machine making or assembling the part, and a certain limit process. Neither involves thermodynamic reasoning.

A new multi-scale curved beam based model was developed for piston-ring designs. This paper describes the free-shape, force in circular bore and closed shape within a flexible band (ovality) related parts. Knowing any one of these distributions, this model determines the other two. This tool is useful in the sense that the characterization of the ring is carried out by measuring its closed shape within a flexible band which is more accurate than measuring its free shape or force distribution in circular bore. Thus, having a model that takes the closed shape within a flexible band as an input is more convenient and useful based on the experiments carried out to characterize the ring.

A new variable compression turbo (VC-Turbo) engine, which has a multi-link system for controlling the compression ratio from 8:1 to 14:1, requires high axial force for fastening the multi-links because of high input loads and the downsizing requirement. Therefore, it was necessary to develop a 1.6-GPa tensile strength bolt with plastic region tightening. One of the biggest technical concerns is delayed fracture. In this study, quenched and tempered alloy steels were chosen for the 1.6-GPa tensile strength bolt.

The Wankel rotary engine is more compact than conventional piston engines, but its oil and fuel consumption must be reduced to satisfy emission standards and customer expectations. A key step toward this goal is to develop a better understanding of the apex seal lubrication to reduce oil injection while reducing friction and maintaining adequate wear. This paper presents an apex seal dynamics model capable of estimating relative wear and predicting friction, by modeling the gas and oil flows at the seal interfaces with the rotor housing and groove flanks. Model predictions show that a thin oil film can reduce wear and friction, but to a limited extent as the apex seal running face profile is sharp due to the engine kinematics.

A suitable GF-5 engine oil formulation is investigated to improve the fuel economy of gasoline engines with hydrogen-free DLC-coated valve lifters. Molybdenum dithocarbamate (MoDTC) is shown to be a suitable friction modifier for low viscosity grade engine oils like 0W-20. A suitable Ca salicylate detergent is also determined from several types examined for maximizing the friction reduction effects of MoDTC. The most suitable Ca salicylate has a chemical structure capable of forming a borophosphate glass film on metal surfaces, which is known to improve the effects of MoDTC. A high viscosity index Group III base oil (VI>140) is also effective in improving fuel efficiency. It is further clarified that the structural design of the polymethacrylate viscosity modifier is another important factor in reducing engine friction.

During this decade, the constant increase and globalization of passenger car sales has led countries to adopt a common language for the treatment of CO2 and other pollutant emissions. In this regard, the WLTC - World-wide harmonized Light duty Test Cycle - stands as the new global reference cycle for fuel consumption, CO2 and pollutant emissions across the globe. Regulations keep a constant pressure on CO2 emission reduction leading vehicle manufacturers and component suppliers to modify hardware to ensure compliance. Within this balance, lubricants remain worthwhile contributors to lowering CO2 emission and fuel consumption. Yet with WTLC, new additional lubricant designs are likely to be required to ensure optimized friction due to its new cycle operating conditions, associated powertrain hardware and worldwide product use.

An adsorber system for reducing cold-start hydrocarbon (HC) emissions has been developed combining existing catalyst technologies with a zeolite-based HC adsorber. The series flow in-line concept offers a passive and simplified alternative to other technologies by incorporating one additional adsorber substrate into existing converters without any additional valving, purging lines, secondary air, or special substrates. Major technical issues to be resolved for practical use of this system are 1) the ability to adsorb a wide range of HC molecular sizes in the cold exhaust gas and 2) the temperature difference between HC desorption from the adsorber and activation of the catalyst to convert desorbed HCs. This paper describes the current development status of hydrocarbon adsorber aftertreatment technologies. We report results obtained with a variety of adsorber properties, washcoat structures of adsorber catalyst and start-up and underfloor catalyst system combinations.

The liquid fuel entry into the cylinder and its subsequent behavior through the combustion cycle were observed by a high speed CCD camera in a transparent engine. The videos were taken with the engine firing under cold conditions in a simulated start-up process, at 1,000 RPM and intake manifold pressure of 0.5 bar. The variables examined were the injector geometry, injector type (normal and air-assisted), injection timing (open- and closed-valve injection), and injected air-to-fuel ratios. The visualization results show several important and unexpected features of the in-cylinder fuel behavior: 1) strip-atomization of the fuel film by the intake flow; 2) squeezing of fuel film between the intake valve and valve seat at valve closing to form large droplets; 3)deposition of liquid fuel as films distributed on the intake valve and head region. Some of the liquid fuel survives combustion into the next cycle.

Mo-free 1.6-GPa bolt was developed for a Variable Compression Turbo (VC-Turbo) engine, which is environment friendly and improves fuel efficiency and output. Mo contributes to the improvement of delayed fracture resistance; therefore, the main objective is to achieve both high strength and delayed fracture resistance. Therefore, Si is added to the developed steel to achieve high strength and delayed fracture resistance. The delayed fracture tests were performed employing the Hc/He method. Hc is the limit of the diffusible hydrogen content without causing a delayed fracture under tightening, and He is the diffusible hydrogen content entering under a hydrogen-charging condition equivalent to the actual environment. The delayed fracture resistance is compared between the developed steel and the SCM440 utilized for 1.2-GPa class bolt as a representative of the current high-strength bolts.