Paper delivered to the Natural Gas Vehicles Conference Buenos Aires

October 2004

Dual fuel allows Euro II without a catalyst on 1960’s engine designs

Abstract

Diesel engines designed in the 1950’s and 1960’s fail to meet modern emissions standards. A dual fuel engine management system, mechanical design changes and application engineering processes were developed and applied to two engine types of this vintage with the aim of meeting Euro II 1998 emissions standards using the R49 test cycle in an uncertified test cell that allowed comparative testing.
To allow the Daimler Benz OM355 and OM314 diesel engines to meet Euro II standards under these conditions required the innovative application of modern electronic controls, few mechanical changes and the application of alternative engine management and control processes to ensure success. No exhaust gas catalyst was required. 90% substitution at full load was achieved while the power and torque matched that of the diesel engines. Fuel efficiency on dual fuel at full load was improved by more than 10%.