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SCIP Simplified Direct Injection for Cleaning the 2-3 Wheeler Two-Stroke Engines
ISSN: 0148-7191, e-ISSN: 2688-3627
Published January 13, 1999 by The Automotive Research Association of India in India
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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 poppet valve used for low pressure air assisted direct injection of fully atomized fuel, is here mechanically actuated by a diaphragm driven by pressures from the engine. The SCIP air assisted injector unit can be easily bolted on existing 2-stroke cylinder heads with minimum engine intrusion and redesign.
To be combined with the SCIP technology and hardware, Sagem has developed a low cost Engine Management System (EMS) including low pressure mass produced Electronic Fuel Injection (EFI) components for fuel metering. The key features of the Sagem MC 500 SCIP system are described in details. It also includes additional enhancement capabilities, such as lubrication oil control, vehicle anti-theft, etc.
After preliminary development and endurance testing carried out on a 125 cc 2-stroke scooter engine, the SCIP system has more recently been applied to a 50 cc demonstration scooter vehicle. Such vehicle has shown the SCIP capability to meet the European 1999 emissions regulation (which can be compared to the Indian 2000 regulation for Two-wheelers), while maintaining typical 50 cc scooter driveability and high performance characteristics with engine speeds up to about 10000 RPM. Following this demonstration, several SCIP development programs are now being undertaken by IFP in association with Sagem in order to satisfy the requirements of specific customers applications.
Therefore, the SCIP system appears as a simple, highly efficient and easy way to reduce pollutants emissions and fuel consumption of small 2-stroke engines of cylinder displacement from 50 to more than 150 cc, which corresponds to the most popular Indian 2-3 wheeler market.
CitationDouaud, A., Duret, P., Lavy, J., Venturi, S. et al., "SCIP Simplified Direct Injection for Cleaning the 2-3 Wheeler Two-Stroke Engines," SAE Technical Paper 990038, 1999, https://doi.org/10.4271/990038.
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