Technology Options for Control of Emissions in Two Wheelers

The need to control the emissions from two wheelers is well-known. India is the second largest producer of two wheelers in the world next only to China. The two wheelers are powered by either two stroke or four stroke engines. The two stroke engines though simple in design has the drawback of high exhaust emissions and poor fuel economy. The four stroke engines on the other hand have much more moving parts but they have the advantages of lesser exhaust emissions and better fuel economy. The mechanism of pollutant formation in S.I. Engines is briefly explained and the logical evolution of control techniques is discussed in this paper. Example: Two stroke engines with catalyst - Progress and Limitations, four stroke engines with simple mechanically controlled carburettor or advanced constant depression carburettors, secondary air valve, catalyst and other devices such as bimetal switching valve, accelerating pump etc. which will help in overall lean mixture operation but provide enrichment for transients such as cold start, acceleration etc. are discussed. The choice of one or more units in combination will depend on the regulations to be met, durability requirements, cost considerations and compromise with respect to starting effort, durability and fuel economy.

The development work of Electronic Fuel Injection System for both two stroke and four stroke small vehicle engines by SYNERJECT Systems Integration in Australia is also presented as potential future technology options.