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A new concept for high efficiency two-stroke cycle spark-ignition engines has been developed. The installation of the IFP-developed pneumatic fuel injection process in a two-stroke engine allows the introduction of the fuel separately from the scavenging air, in order to minimize fuel shortcircuiting. The process does not require an external air pump since the compressed air used to atomize the fuel is supplied at no expense by the crankcase. The premixed charge is delivered directly into the cylinder with a high spray quality, its stratification for the optimization of combustion is controlled by a valve. This process, therefore, provides the advantages of the direct injection but uses commercially available gasoline injectors. A single-cylinder engine has been developed first to verify the potential of the process.

The implementation of the IFP developed Compressed Air Assisted Fuel Injection Process (named IAPAC) in a two-stroke engine allows the introduction of the fuel separately from the scavenging air, which in consequence minimizes fuel short-circuiting. The inherent mechanical principle of the IAPAC process which uses the crankcase compressed air to finely atomize the fuel, provides the advantages of direct injection but in addition uses conventional low pressure automotive type injection technology with commercially available gasoline injectors. In earlier work we showed an example of the application of this fuel injection technology to a PIAGGIO single cylinder 125 cc scooter two-stroke engine. In this paper, an update of the results obtained with this new engine is presented and confirms the ultra-low emissions capability for two-wheeler application.

The IAPAC Compressed Air Assisted Fuel Injection has been applied to the design and conception of a new 3 cylinder automotive 2-stroke engine of 1230 cc. This engine includes several innovations in addition to the IAPAC technology itself: fluid dynamically controlled combustion process (FDCCP), compactness with the block-integration of the IAPAC components, combined camshaft-balancing shaft, fixed exhaust port timing, … it presents particularly advantageous characteristics in terms of size and weight. The optimization of the different engine design parameters, before the installation of the engine in a vehicle, is presented in this paper. High engine trapping efficiency and smooth, stable and highly efficient light load auto-ignition combustion (ATAC) is controlled by the internal fluid dynamics. For the in-vehicle calibration, a fast catalyst lighting strategy has been implemented.

The IAPAC® Direct fuel Injection (DI) system, developed by IFP, has already well proven its capability to reduce pollutants emissions and fuel consumption of 2-stroke engines for both 2-wheeler and marine outboard application. This crankcase Compressed Air Assisted Fuel Injection process allowing the introduction of the fuel separately from the scavenging air, minimizes the fuel short-circuiting and has shown its potential on various prototype demonstrators. This paper presents the development and pre-industrialization work performed to apply this concept to an SELVA Marine 2-cylinder 50 HP outboard 2-stroke engine. A standard carbureted engine has been converted to a IAPAC® prototype engine by mainly modifying the cylinder head. Then, this prototype engine has been calibrated, tested and optimized on the dyno test bench to comply with future emissions regulation while keeping similar power output than the reference carbureted engine.

The implementation of the IFP-developped Compressed Air Assisted Fuel Injection process (named IAPAC) on a two-stroke engine allows the introduction of the fuel separately from the scavenging air in order to minimize fuel short-circuiting. The IAPAC process does not require an external air pump since the compressed air used to atomize the fuel is supplied, at no expense, by the crankcase. The premixed charge is delivered directly into the cylinder with a high spray quality and its stratification, for optimized combustion, is controlled by a valve. This process, therefore, provides the advantages of the direct injection but uses conventional low-pressure automotive type injection technology with commercially available gasoline injectors. In earlier work, we showed how the qualities of light weight, compactness, high specific power, high efficiency and low emissions make this concept particularly well-adapted for future automotive applications.

The implementation of the IFP-developped Compressed Air Assisted Fuel Injection process (named IAPAC) on a two-stroke engine allows the introduction of the fuel separately from the scavenging air in order to minimize fuel short-circuiting. The IAPAC process does not require an external air pump since the compressed air used to atomize the fuel is supplied, at no expense, by the crankcase. The premixed charge is delivered directly into the cylinder with a high spray quality and its stratification, for optimized combustion, is controlled by a valve. This process, therefore, provides the advantages of the direct injection but uses conventional low-pressure automotive type injection technology with commercially available gasoline injectors. In earlier work we showed how the qualities of light weight, compactness, high specific power, high efficiency and low emissions make this concept particularly well-adapted for future automotive applications.

The purpose of the 4-SPACE (4-Stroke Powered gasoline Auto-ignition Controlled combustion Engine) industrial research project is to research and develop an innovative controlled auto-ignition combustion process for lean burn automotive gasoline 4-stroke engines application. The engine concepts to be developed could have the potential to replace the existing stoichiometric / 3-way catalyst automotive spark ignition 4-stroke engines by offering the potential to meet the most stringent EURO 4 emissions limits in the year 2005 without requiring DeNOx catalyst technology. A reduction of fuel consumption and therefore of corresponding CO2 emissions of 15 to 20% in average urban conditions of use, is expected for the « 4-SPACE » lean burn 4-stroke engine with additional reduction of CO emissions.

The purpose of the European « SPACE LIGHT » (Whole SPACE combustion for LIGHT duty diesel vehicles) 3-year project launched in 2001 is to research and develop an innovative Homogeneous internal mixture Charged Compression Ignition (HCCI) for passenger cars diesel engine where the combustion process can take place simultaneously in the whole SPACE of the combustion chamber while providing almost no NOx and particulates emissions. This paper presents the whole project with the main R&D tasks necessary to comply with the industrial and technical objectives of the project. The research approach adopted is briefly described. It is then followed by a detailed description of the most recent progress achieved during the tasks recently undertaken. The methodology adopted starts from the research study of the in-cylinder combustion specifications necessary to achieve HCCI combustion from experimental single cylinder engines testing in premixed charged conditions.

The implantation of the IFP-developed Compressed Air Assisted Fuel Injection process (IAPAC) in a two-stroke engine allows the introduction of the fuel separately from the scavenging air,in order to minimize fuel shortcircuiting. In earlier work, we achieved a drastic reduction of emissions using the IAPAC fuel injection process. Here, we give a precise analysis of the origin of the remaining pollution. The purpose of this analysis is to evaluate the real potential of a high efficiency two-stroke engine in comparison to conventional four-stroke engines, and to define the areas most needful of further development. The new results obtained pointed out how the IAPAC system is particularly well-adapted to take optimum advantages of the two-stroke-cycle principle.

The IAPAC Direct fuel Injection (DI) system, developed by IFP, has already well proven its capability to reduce pollutants emissions and fuel consumption of 2-stroke engines. This crankcase Compressed Air Assisted Fuel Injection Process allowing the introduction of the fuel separately from the scavenging air, minimizes the fuel short-circuiting. In earlier works, results of the implementation of the IAPAC system on cylinder displacement from 125 cc to 400 cc have been presented in various papers. These first prototypes were all using a camshaft to drive the IAPAC DI poppet valve, which was considered as a limitation for applying this system to small displacement 2-stroke engines. The new SCIP™ system is no more using a camshaft neither driveshaft, or any electric power supply to drive the DI air assisted injection valve.

The IAPAC Direct fuel Injection (DI) system, developed by IFP, has already well proven its capability to reduce pollutants emissions and fuel consumption of 2-stroke engines. This crankcase Compressed Air Assisted Fuel Injection Process allowing the introduction of the fuel separately from the scavenging air, minimizes the fuel short-circuiting. In earlier works, results of the implementation of the IAPAC system on cylinder displacement from 125 cc to 400 cc have been presented in various papers. These first prototypes were all using a camshaft to drive the IAPAC DI poppet valve, which was considered as a limitation for applying this system to small displacement 2-stroke engines. The new SCIP™ system is no more using a camshaft neither driveshaft, or any electric power supply to drive the DI air assisted injection valve.

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).