The Potential of Gasoline Direct Injection for Small Displacement 4-Stroke Motorcycle Applications



Small Engine Technology Conference & Exposition
Authors Abstract
With the introduction of increasingly more stringent emission standards, Engine Management Systems (EMS), including port fuel injection, are now being introduced in the 4-stroke motorcycle marketplace. These systems have been generally derived from the automotive industry, albeit with some significant changes to satisfy the strict cost and packaging constraints of the motorcycle applications.
Direct injection (DI) is positioned to become one of the next generation of technologies for the automotive engine, offering the potential for improved fuel economy, performance and emissions control. Direct injection can also provide similar benefits for motorcycle applications. However, direct transfer of the current production automotive systems is unlikely to suit the requirements of motorcycle applications, due to some of the specific challenges faced in the motorcycle market.
For small displacement motorcycle applications, a central injection, spray guided DI combustion may offer the characteristics required to meet many of the challenges of this difficult application. To demonstrate the potential of such an application, a 125cc engine has been developed using an air-assist DI spray guided combustion system. Results from the engine show significant fuel economy improvements when compared to the baseline carbureted engine, as well as potential to meet current and future emissions legislations with a variety of system configurations.
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Cathcart, G., Houston, R., and Ahern, S., "The Potential of Gasoline Direct Injection for Small Displacement 4-Stroke Motorcycle Applications," SAE Technical Paper 2004-32-0098, 2004,
Additional Details
Sep 27, 2004
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Content Type
Technical Paper