Ashok Leyland develops India's first MPFI CNG engine for buses

Ashok Leyland has developed the country's first one-litre-per-cylinder 6 cylinder CNG engine for buses employing multi point fuel injection (MPFI). The commercial vehicles manufacturer says its W06DTI 'H' series CNG engine combines superior power rating (135 kW @ 2400 rpm) with low emissions.

The company said this 5.7-litre turbocharged inter-cooled natural gas engine meets Euro IV emission standards, and potentially the Euro V.

"With this engine, we step into the more challenging phase of transient cycles mandated in the Euro IV norms of the future," says R Seshasayee, managing director, Ashok Leyland.

The engine uses stoichiometric combustion technology (chemically correct air-fuel ratio) in combination with three-way catalytic converter to reduce the emissions to the lowest level possible. The multi point fuel injection system delivers the required gas quantity at the intake manifold, as per the vehicle demand even in transient operating conditions.

The exhaust gas re-circulation (EGR) used in this engine not only lowers the NOx emission but also restricts the thermal load on the engine components. The quantity of EGR is controlled by the difference in pressures between exhaust manifold and the turbocharger's compressor inlet. The waste gate turbocharger is optimized for max torque.

The engine features electronics provided by a new state-of-the-art electronic control unit (ECU) that controls the sequential gas injection and high-energy ignition systems. The plug-on coils used in the engine, along with long life spark plug, makes for maintenance-free operation of the vehicle.

Designed and optimised for high power and torque output with low fuel consumption and emission levels, the engine offers better fuel efficiency compared to any engine of its class and is expected to provide value to the customer with low life cycle costs.

"Having developed in-house the first CNG bus engine in India a decade ago, the first MPFI CNG engine in Indian auto sector is another proud achievement of our in-house capabilities," Seshasayee adds.