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The paper discusses the benefits of a four stroke engine having one intake and one exhaust rotary valve. The rotary valve has a speed of rotation half the crankshaft and defines an open passage that may permit up to extremely sharp opening or closing and very large gas exchange areas. The dual rotary valve design is applied to a racing engine naturally aspirated V-four engine of 1000cc displacement, gasoline fuelled with central direct injection and spark ignition. The engine is then modeled by using a 1D engine & gas dynamics simulation software package to assess the potentials of the solution. The improved design produces much larger power densities than the version of the engines with traditional poppet valves revving at higher speeds, with reduced frictional losses, and with larger gas exchange areas while also improving the fuel conversion efficiency thanks to the sharpness of opening or closing events.

The paper presents a novel design for a two stroke thermal engine that delivers excellent fuel economy and low emissions within the constraints of today's cost, weight and size. The engine features asymmetrical port timing through a novel translating and rotating piston mechanism. The engine is externally scavenged and supercharged, has wet sump and oil pressure lubrication, direct injection, it is lightweight, easy to build, with minimal number of parts, low production cost, ability to be balanced and compact design. The two stroke mechanism produces a linear motion of the pistons as well as an elliptical path on the surface of the cylinder. This allows the piston to sweep as well as travel past the ports. Suitable slots around the raised lip of the piston generate the asymmetry that makes the exhaust port to open first and to close first. The inlet port remains open to complete the cylinder charging and allow supercharging. Direct fuel injection is adopted for best results.

The Wankel engine for Unmanned Aerial Vehicle (UAV) applications delivers advantages vs. piston engines of simplicity, smoothness, compactness and high power-to-weight ratio. The use of computational fluid dynamic (CFD) and computer aided engineering (CAE) tools may permit to address the major downfalls of these engines, namely the slow and incomplete combustion due to the low temperatures and the rotating combustion chambers. The paper proposes the results of CAD/CFD/CAE modelling of a Wankel engine featuring tangential jet ignition to produce faster and more complete combustion.

The paper discusses the benefits of a four stroke engine having one intake and one exhaust rotary valve. The rotary valve has a speed of rotation half the crankshaft and defines an open passage that may permit up to extremely sharp opening or closing and very large gas exchange areas. This design also permits central direct injection and ignition by spark or jets. The dual rotary valve design is applied to a naturally aspirated V-four engine of 1000cc displacement, gasoline, methane or hydrogen fuelled with central direct injection and spark ignition. The engine is modeled by using a 1D engine & gas dynamics simulation software package to assess the potentials of the solution. The novelty in the proposed dual rotary valve system is the combustion chamber of good shape and high compression ratio with central direct injector and spark plug or jet ignition, coupled to the large gas exchange areas of the rotary system.

The World Championship Grand Prix (WCGP) is the premier championship event of motorcycle road racing. The WCGP was established in 1949 by the sport's governing body, the Fédération Internationale de Motocyclisme (FIM), and is the oldest world championship event in the motorsports arena. This book, developed especially for racing enthusiasts by motorsports engineering expert Dr. Alberto Boretti, provides a broad view of WCGP motorcycle racing and vehicles, but is primarily focused on the design of four-stroke engines for the MotoGP class. The book opens with general background on MotoGP governing bodies and a history of the event’s classes since the competition began in 1949. It then presents some of the key engines that have been developed and used for the competition through the years. Technologies that are used in today’s MotoGP engines are discussed.

The paper considers different options to design a multi fuel engine retaining the power densities and efficiencies of the latest Diesel heavy duty truck engines while operating with various other fuels. In a first option, an igniting Diesel fuel is coupled to a main fuel that may have any Cetane or octane number in a design where every engine cylinder accommodates a direct Diesel injector, a glow plug and the multi fuel direct injector in a bowl-in-piston combustion chamber configuration. Alternatively, an igniting gasoline fuel replaces the Diesel fuel in a design where every engine cylinder accommodates a gasoline direct injector, the multi fuel direct injector and a jet ignition pre chamber also with a bowl-in-piston combustion chamber configuration. Both these designs permit load control by changing the amount of fuel injected and Diesel-like, gasoline-like and mixed Diesel/gasoline-like modes of operation modulating the amount of the multi fuel that burn premixed or diffusion.

With the purpose of reducing emission level while maintaining the high torque character of diesel engine, various solutions have been proposed by researchers over the world. One of the most attractive methods is to use dual fuel technique with premixed gaseous fuel ignited by a relatively small amount of diesel. In this study, Methane (CH4), which is the main component of natural gas, was premixed with intake air and used as the main fuel, and diesel fuel was used as ignition source to initiate the combustion. By varying the proportion of diesel and CH4, the combustion and emissions characteristics of the dual fuel (diesel/CH4) combustion system were investigated. Different cases of CFD studies with various concentration of CH4 were carried out. A validated 3D quarter chamber model of a single cylinder engine (diesel fuel only) generated by using AVL Fire ESE was modified into dual fuel mode in this study.

Cylinder deactivation has been proposed so far for improved part load operation of large gasoline engines. In all this application, the cylinder deactivation has been achieved keeping the intake and exhaust valves closed for a particular cylinder, with pistons still following their strokes. The paper presents a new mechanism between the piston and the crankshaft to enable selective deactivation of pistons, therefore decoupling the motion of the piston from the rotation of the crankshaft. The reduced friction mean effective pressure of the new technology enables the use of piston deactivation in large engines not necessarily throttle controlled but also controlled by quantity of fuel injected. Results of performance simulations are proposed for a HSDI V8 engine, producing significant savings during light operation.

Direct injection and jet ignition is becoming popular in electrically assisted, turbocharged, F1 engines because of the pressure to reduce fuel consumption. Operation from homogeneous stoichiometric up to lean of stoichiometry stratified about λ = 1.5, occurs with fast combustion of reduced cyclic variability thanks to the enhanced ignition by multiple jets of hot, partially reacting products travelling through the combustion chamber. The fuel consumption has thus been drastically reduced in an engine that is, however, still mostly throttle controlled. The aim of the present paper is to show the advantages of direct injection and jet ignition based on model simulations of the operation of a high-performance throttle-controlled engine featuring rotary valves.

The present paper is an introduction to a novel rotary valve engine design addressing the major downfalls of past rotary valves applications while permitting the typical advantages of the rotary valves. Advantages of the solution are the nearly optimal gas exchange, mixture formation, ignition and combustion evolution thanks to the large gas exchange areas from the two horizontal valves per engine cylinder, the good shape of the combustion chamber, the opportunity to place a direct fuel injector and a spark or jet ignition device at the centre of the chamber. The novel engine design also permits higher speed of rotation not having reciprocating poppet valves and the reduced friction losses of the rotating only distribution. This translates in better volumetric efficiencies, combustion rates and brake mean effective pressures for improved power density and fuel efficiency. Additional advantages are the reduced weight and the better packaging.