The advent of April 2005 saw the introduction of Bharat Stage-III (akin to Euro-III) norms in 11 major Indian Cities for all class of vehicles and 74 dB(A) vehicle pass by requirement as per EEC homologation norms for M1 class of vehicles across the country.
This paper summarizes development methodology investigated and adopted for 3.0 lit direct injection, naturally aspirated diesel engine with cam driven mechanical fuel injection equipment on multi utility vehicle. This lean technical package compared to the trends of using turbocharger, intercooler and electronic common rail system was conceived to meet the requirement of low cost product offering.
The base engine was a derivative of commercial vehicle engine with design features posing significant challenge to achieve the impending regulatory requirements.
The emission optimization work included improving in-cylinder combustion parameters through combustion cavity, injection parameters, exhaust gas recirculation coupled with moderate exhaust gas after-treatment.
Optimisation of electronically controlled exhaust gas recirculation, coupled with better swirl management proved to be useful in bringing emissions within Bharat Stage-III box on chassis dynamometer trials (ECE + EUDC 90 cycle).
Noise refinement work included base line NVH analysis (1 m airborne noise assessment) followed by near field sound intensity measurements and structural vibration measurements to determine the sound power contribution of the radiating surface parts. The prominent noise sources were then subjected to design countermeasures to maximize noise reduction.