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The major area in which the automotive manufacturers are working is to produce high-performance vehicles with lighter weight, higher fuel economy and lower emissions. In this regard, hollow camshafts are widely used in modern diesel and gasoline engines due to their inherent advantages of less rotational inertia, less friction, less weight and better design flexibility. However, the dynamic loads of chain system, valve train and fuel injection pump (if applicable) makes it challenging to design over-head hollow camshafts with the required factor of safety (FOS).In the present work, high-fidelity FE model of a hollow camshaft assembly is simulated to evaluate the structural performance for assembly loads, valve train operating loads, fuel injection pump loads and chain system loads. The investigation is carried out in a high power-density (70 kW/lit) 4-cylinder in-line diesel engine. The camshaft is used for operating the intake valves which induce varying stresses in-line with the engine firing order. Moreover, the camshaft is also used to drive the high-pressure fuel injection pump (FIP) at the rear-end which can add significant torsional stresses. Furthermore, the stresses induced by the hub-loads of timing chain is found to be having a significant effect on the bending behavior of the front-end of the camshaft. In addition to these operating stresses, the camshaft is subjected to different kinds of mean stresses induced by the bolt (used to fasten the drive-sprocket) and interference fit of the camshaft child parts (cam and front plug). Hence, the authors propose a robust and reliable evaluation methodology to evaluate the structural performance and factor of safety (FOS). The dynamic bending behavior of the camshaft under press-fit loads of cam lobes and front plug is discussed. The present work also covers the load-path and multi axial stress state induced on the hollow camshaft under varying load conditions apart from estimating the fatigue life. Moreover, the investigation includes the assessment of different parameters influencing the stress multi-axiality on the camshaft to arrive at potential improvements in the camshaft design. Overall, the results arrived using this methodology is found to be having a good correlation with the parts used for durability testing. Thus, the proposed methodology can be used for evaluating hollow camshafts of modern engines subjected to complex and highly dynamic loads.

The fuel economy of the internal combustion engine becomes progressively critical, especially with the stringent standards set by the government. To meet the government norms such as CAFE (Corporate Fuel Average Economy), different technologies are being explored and implemented in internal combustion engines. Several technologies such as variable oil pump, map controlled PCJ (Piston Cooling Jet), variable or switchable water pump & ball bearing turbocharger etc. This study investigates the effectiveness of implementing map-controlled PCJ implemented for a 1.5-litre 3-cylinder diesel engine.PCJ’s are major consumers of oil flow and map-controlled PCJ is used by many OEM’s e.g., Ford EcoSport to reduce the oil pump flow. In map-controlled PCJ, the oil to the PCJ is controlled using a solenoid valve. The solenoid valve can be completely variable or ON/OFF type. In our application, the ON/OFF type solenoid value is used to regulate the oil flow to PCJ. Conventionally, the oil to the PCJ is supplied at all operating conditions of the engine, even when the piston temperature is within the material acceptable limit. This adds to the parasitic loss of the internal combustion engine, due to the high friction power consumed by the oil pump to meet the oil flow rate requirement. Using the solenoid-controlled PCJ along with Variable Displacement Oil Pump (VDOP), the flow to the PCJ can be shut down at certain operating conditions such as high speed, and low load conditions. Using the VDOP, the total oil flow rate can be reduced whenever there is no flow to the PCJ, this will help to reduce engine friction load & improve the overall fuel economy.The objective of the paper is to show the systemic approach, design modifications & challenges involved in the implementation of the map controlled PCJ. The final engine with the map-controlled PCJ along with VDOP is evaluated in the NEDC (New European Driving Cycle) drive cycle to understand the benefits & an overall fuel economy of 1 – 2 % was observed. Results are discussed in detail, which have enabled to take required decision on implementation of Map Controlled PCJ in the specific engine application.

The Introduction of Corporate Average Fuel Economy (henceforth will be addressed as CAFE) regulations demand suitable technological upgrades to meet the significant increase in targets of vehicle fleet fuel economy. Engine Downsizing and Friction Reduction measures help in getting one step closer to the target. In a Conventional Oil Pump, the pump discharge flow and pressure are a direct function of operating speed. There is no control over lubricant flow which results in increased power and fuel consumption due to its unnecessary pumping characteristics irrespective of the actual engine demand. This paper discusses the introduction of a variable displacement oil pump (henceforth will be addressed as VDOP) that was adapted to a 1.5-liter 3 Cylinder Diesel Engine. This approach helps the system to reduce parasitic losses as the oil flow is regulated based on the mechanical needs of the engine. The flow is regulated with help of a solenoid valve which receives input from the ECU. The engine Oil Pump has a major role in enabling the transfer of lubricant to all moving engine components. The demand majorly depends on engine performance characteristics, bearing clearances, operating temperatures, and wear behavior of engine components. The paper explains the boundary conditions for VDOP design packaging, challenges in system adaptation, impact on engine lubrication circuit, performance, and friction reduction benefit.

The global automotive industry is growing rapidly in recent years and the market competition has increased drastically. There is a high demand for passenger car segment vehicles with high torque delivery and fuel economy for a pleasant drivability experience. Also, to meet the more stringent emission requirements, automakers are trying very hard to reduce the overall vehicle gross weight. In lowering both fuel consumption and CO2 generation, serious efforts have been made to reduce the overall engine weight. An engine cylinder block is generally considered to be the heaviest part within a complete engine and block alone accounts for 3-4% of the total weight of the average vehicle, thus playing a key role in weight reduction consideration. Aluminum casting alloys as a substitute for the traditional cast iron can mean a reduction in engine block weight between 40 and 55% [9], even if the lower strength of aluminum compared to grey cast iron is considered. Thus, designers of aluminum engine blocks are constantly striving to design better and lighter blocks in order to improve and enhance the efficiency of automobile engines.This work is a part of design and development of 2.2 L, 4-cylinder turbocharged intercooler (TCIC) diesel engine for a complete new monocoque vehicle platform, focused on automotive passenger car application with high operating in cylinder combustion pressures around 190 bar. The paper portrays the effective system approach essential for selecting aluminum as the choice of material, selection of alloy composition, casting process, heat treatment and key design criteria. The ongoing substitution of cast iron in engine blocks by aluminum casting alloys also requires the design and development of a new “tribological” system. Selection of cost-effective cylinder liner system and the drawbacks of this heterogeneous concept such as the lack of metallic bonding with the surrounding cast aluminum alloy and higher bore distortion are addressed during design and development. Statistical database, quality tools like design failure mode and effect analysis (DFMEA), design for manufacture and assembly (DFMA) etc., classical design methods, finite element analysis (FEA), advanced computer-aided engineering (CAE) and computational fluid dynamics (CFD) simulation tools have helped in materializing this concept into production. Experimental validation of the design is carried out as a part of design verification and validation. And results are elaborated to show the effectiveness of integrated approach used for the development program.