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Fuel Injection for Low Emission 50cc 2-Stroke Scooter
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 28, 2010 by SAE International in United States
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The ideal attributes of light weight, low cost and high power density have made the 2-stroke engine unrivalled in the scooter and moped market for many years.
However, the challenges of meeting new emissions regulations, especially the latest Euro III emission test cycle have reduced the 2-stroke's dominance and it is now often considered to be too dirty and inefficient to have a future. As a result its product placement is on the decline.
This paper introduces and discusses the latest application of a low-cost high-frequency injection system (Pulse Count Injection [ 1 , 2 ]) to both the fuel flow and lubrication oil flow of a 2-stroke scooter; allowing both fluids to be individually mapped and optimised for the complete engine operating range. This in turn enables the 2-stroke engine to pass the latest Euro III test whilst improving the fuel economy by a considerable margin, without changing the architecture of the engine.
Examples of the latest developments of a highly integrated engine management system, including fuel and oil injector technology are shown.
The paper draws conclusions from the test results showing the clear benefits of electronic fuel injection both for emissions and fuel consumption, and demonstrates that these benefits are achievable from a compact well integrated throttle body unit suitable for the small 2-stroke engine market.
CitationRavenhill, P., Allen, J., Smither, B., Farmer, G. et al., "Fuel Injection for Low Emission 50cc 2-Stroke Scooter," SAE Technical Paper 2010-32-0020, 2010, https://doi.org/10.4271/2010-32-0020.
- Allen, J., Ravenhill, P., Flow and Spray Characteristics of a High Frequency Low Cost Fuel Injection System for Small Engines., ICLASS-2006, Kyoto, Japan. Paper no. ICLASS06-243
- Ravenhill, P., Drake, T., Hoolahan, R., Smither, B. et al., “Low Cost Electronic Fuel Injection for Motorcycles and Utility Engines,” SAE Int. J. Engines,2(2):764-774, 2009, doi:10.4271/2009-32-0149.
- Houston, R., Archer, M., Moore, M., and Newman, R., “Development of a Durable Emissions Control System or an Automotive Two-Stroke Engine,” SAE Technical Paper 960361, 1996.
- Duret, P. and Moreau, J.-F., “Reduction of Pollutant Emissions of the IAPAC Two-Stroke Engine with Compressed Air Assisted Fuel Injection,” SAE Technical Paper 900801, 1990.
- Blair,G., Kee,R., Carson,C., Douglas,R., The Reduction of Fuel Consumption by Direct Air-Assisted Fuel Injection into a Two-Stroke Engine. 4th Graz Two-Wheeler Symposium, April 1991.
- Winkler, F., Low presssure fuel injection strategies for low emission two stroke scooter engines. Graz University of technology, 2-Stroke Symposium, Monza, 2009.
- Cunningham, G., Kee, R.J., Kenny, R.G., and Skelton, W.J., “Development of a Stratified Scavenging System for Small Capacity Two-Stroke Engines,” SAE Technical Paper 1999-01-3270, 1999.
- Stihl advanced 2-stroke engine with Stratified Scavenging http://www.stihl.com/isapi/default.asp?contenturl=/knowhow/producttechnics/stihlengines/2_stroke/default.htm
- Gunthner, M., Mugele, M., Tribulowski, J., Spicher, U. et al., “Numerical Analysis of an Air-Head Stratified Scavenging Concept for Emission Reduction of a Two-Stroke Engine,” SAE Technical Paper 2001-24-0051, 2001.
- Allen, J. and Drake, T., “Experimental Results of New Fuelling Strategies for High Frequency Low Cost Injection Systems for Small Engines,” SAE Technical Paper 2007-32-0051, 2007.
- Douglas, R., “AFR and Emissions Calculations for Two-Stroke Cycle Engines,” SAE Technical Paper 901599, 1990.