Browse Publications Technical Papers 1999-01-1247

Fuel Consumption and Emission Reduction of a Small Two-Stroke Engine Through Air-Assisted Fuel Injection and Delayed-Charging 1999-01-1247

The classical small two-stroke engine is mechanically simple with a high power-to-weight ratio. But direct fuel losses are high and therefore induce a high fuel consumption and an unacceptable pollution level. We have developed a simple device (named Delayed-Charging) which is able to largely reduce fuel losses by almost separating the scavenging and fuel-charging functions and, consequently, retaining the major part of delivered fuel in the cylinder. Recent improvements, by use of an air-assisted injection combined with an air curtain to deviate the fuel spray trajectory throughout the cylinder, lead to a further reduction of hydrocarbon emission level from 4% (FIDHC methane equivalent) in a standard carbureted engine down to a 1% level associated to a fuel consumption reduction within a larger speed range in our newly modified 50 cc engine.
To better understand the behavior of the fuel flow, a local instantaneous fuel-concentration measurement in the exhaust duct by a continuous Laser Induced Fluorescence (LIF) process (with a Argon Laser beam) is associated to the continuous mean measurement of HC emission, giving information on the fuel transport and utilization throughout the engine.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.