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For domestically produced passenger car gasoline fuelled vehicles, the forthcoming task of emissions compliance in India (Bharat-IV by 2010) may require a more detailed knowledge of transient engine behaviour by Indian engineers. Under steady state conditions and with reasonable fuel preparation, three-way catalytic converters can remove around 98% of legislated pollutants. However, during cold start and gear changes, the transient emissions are not fully converted by the catalyst; the cold start alone contributing typically 90% of the total Cycle Hydrocarbon (HC) emissions for the Euro- IV drive cycle [1]. This paper presents data measured pre and post the three-way catalyst on a EURO- III compliant European manufactured production Port-Fuel-Injection (PFI) gasoline engine running on a FTP drive cycle. The transient emissions were measured using fast response gas analyzers, with time response giving resolution at better than engine firing frequency.

Ammonia as a fuel suffers from a high ignition energy requirement making it hard to ignite in stoichiometric mixtures, especially with normal spark plugs. On the other hand, pre-chambers are proven to provide high ignition energy by producing multiple ignition spots in the main chamber. A pre-chamber is usually categorized as “active” if it has a dedicated fueling system, and as “passive” if it depends solely on the air- fuel mixture being introduced from the main chamber and is therefore simpler than the active type. In this study, an SI light-duty engine was tested with a conventional spark plug with fuel mixtures of gasoline and gaseous ammonia (0%, 25%, 50%, 75%, 90%, and 100% NH3). The test was then repeated with a passive pre-chamber under the same operating conditions for comparison. Moreover, the engine exhaust was fitted with a fast response analyzer to measure NOX. The use of the conventional spark plug showed stable combustion throughout the fuel mixture sweep.