Mitsubishi New 12.0-Liter Turbocharged and Intercooled Diesel Engine 901572
To meet the increasingly strong demand for high-speed transportation, better fuel economy, higher reliability and the social requirements for more strict Japanese regulations against exhaust and noise emissions, Mitsubishi Motors Corporation has recently developed the 6D40T1 in-line 6-cylinder, 12.0-liter turbocharged and intercooled diesel engine for heavy-duty trucks.
This engine meets the 1989 Japanese exhaust emission regulations and has an output of 258 kW.
To achieve both fuel economy and good drivability, Mitsubishi's original, electronically-controlled fuel injection system was adopted. The so-called prestroke-controlled fuel injection pump is capable of flexible and precise control of both fuel injection rate and timing.
The basic structure of the 6D40T1 was designed with high rigidity to permit high cylinder pressures. In addition, to reduce friction and heat losses, a 4-valve design, roller cam followers with needle roller bearings, and shortened exhaust ports were adopted. As a result, an excellent BSFC level of 189 g/kWh at 1600 rpm was achieved.
Laminated-steel type cylinder head gaskets, high camshaft location, and pistons with cooling channels have been adopted in order to attain sufficient reliability and durability.
The cylinder block, cylinder heads and other structures were designed using a CAD system and assessed beforehand by FEM analyses.
This paper describes the design, development and performance aspects of this engine.