Euro IV equivalent emission norms will be applicable in India in the selected 11 cities from 1st April 2010. There is a large reduction in the Particulates and NOx limits for heavy duty vehicular engines form Euro III to Euro IV. Stringent Euro IV emission limits necessitate fundamental design changes in the combustion system of existing engines, followed by careful ECU calibration.
This paper presents an overview of the work carried out for up-gradation of a 3.9 liter TCIC diesel engine, to make it Euro-IV emission compliant. The base engine for this exercise was selected with a consideration that the strategy can be applicable to mid as well as large size vehicular diesel engines. Major design changes in the baseline engine include design of 4 valve/cyl. cylinder head, valve train, improved combustion system, boosting system involved etc. The mechanical in line fuel injection pump is replaced by high pressure Common Rail fuel injection system with maximum injection pressure capability of 1600 bar.
The most critical phases in this up-gradation work was combustion development and ECU calibration. Response of the combustion package hardware was evaluated in the beginning of the combustion development and then with a systematic combustion mapping exercise where ECU maps were generated to lead towards the targeted emission levels. Steady state emission tuning was followed by integration of after treatment devices and controller tuning for the closed loop control devices for their transient response.
At the end of the development, engine was successfully meeting targeted performance and emissions on ESC, ELR and ETC cycles.