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The recent interest in two-stroke engines for automotive use has produced powerplants of such divergence that as yet, no clear outlook on a likely design is evident. The only common similarity between all the published engines is direct fuel injection. Whilst this is undoubtedly necessary, the effects of exhaust and scavenging systems play a significant role in the overall performance of the engine. This paper initially describes a valve mechanism providing infinitely variable control of the exhaust port opening point, together with the ability to effectively close the exhaust port at the end of the scavenge period. Such a valve has been tested in a single cylinder, 400 cc loop scavenged engine giving encouraging results. The concept of a rotary inlet valve, situated in the cylinder head is also discussed with a view to achieving uniflow scavenging.

The conflicting legislative and performance requirements of the modern automotive engine dictates the detailed optimisation of all features of the design. With this impetus increasing attention is being given to the coolant system where the requirements are for minimum coolant volume and uniform flow distribution. Optimisation of the complex three dimensional coolant system geometry by means of experiment has proven extremely difficult. It is with this background that computational fluid dynamics may prove to have real engineering value providing design solutions that can be incorporated early in the engine design program. A prerequisite however is to demonstrate the accuracy of the analytical technique. This paper describes the comparison of predicted and measured flow fields in a four cylinder engine block.

Designers are under increasing pressure to provide powertrain systems which meet tougher market and legislative requirements for:- performance, emissions and economy reliability and durability noise and refinement To meet increasing competition, powertrain products need to be “fast to market and right first time”. This implies the evolution of existing technology, comprising multi cylinder reciprocating engines and gear transmissions, drawing on a database of decades of powerplant design experience. It is with this background that CAE has proven engineering value supporting key areas of powertrain engineering to meet these technological challenges in a cost effective and timely manner. This paper follows the analytical engineering of a four cylinder engine crankshaft from concept to production design. Particular emphasis is placed on the integration of concept design software tools and the combination of finite element analysis and dynamic models with reduced degrees of freedom.

Lotus Engineering is well known for its ability to improve ride and handling behaviour of cars within short development programmes. This ability has its roots in the extensive cumulative experience of its team of development engineers, coupled with a methodical and analytical approach to subjective iterative vehicle development. Objective testing and modelling techniques are not new to the vehicle development process, but analysis time, complexity and reliability have sometimes limited their contribution in the past and the subjective approach has remained the main driving force. This paper first explains the reasons why Lotus wanted to implement those techniques, what kind of strategy was chosen and what are the results achieved at the moment.

This paper describes the process that redirected research effort from continuously variable transmissions (CVT's) to Smart Transmissions, the electronic control of a conventional manual gearbox. Initially work was carried out on theoretical and existing CVT's, and culminated in the proposal for a system that might solve some of the practical limitations. Following further simulation work comparing the CVT against an intelligently shifted 7 speed gearbox, it was concluded that the Smart Transmission could closely match the CVT for performance and fuel consumption. This meant original targets set by using a CVT could now be met without having to develop new transmission technology. At this point research effort was changed to developing this type of electronically controlled gearbox.

The purpose of the ELEVATE (European Low Emission V4 Automotive Two-stroke Engine) industrial research project is to develop a small, compact, light weight, high torque and highly efficient clean gasoline 2-stroke engine of 120 kW which could industrially replace the relatively big existing automotive spark ignition or diesel 4-stroke engine used in the top of the mid size or in the large size vehicles, including the minivan vehicles used for multi people and family transportation. This new gasoline direct injection engine concept is based on the combined implementation on a 4-stroke bottom end of several 2-stroke engine innovative technologies such as the IAPAC compressed air assisted direct fuel injection, the CAI (Controlled Auto-Ignition) combustion process, the D2SC (Dual Delivery Screw SuperCharger) for both low pressure engine scavenging and higher pressure IAPAC air assisted DI and the ETV (Exhaust charge Trapping Valve).