This report covers a detailed design benchmarking study of the Mercedes OM668 1.7L diesel engine and includes a photographic record of all the main components, plus individual masses and dimensions. Ricardo comments on specific design features are also included.
The Mercedes OM668 engine was developed specifically for the new Mercedes Benz A-class vehicle. The engine has two power variants, each a four-cylinder in-line diesel with direct injection and four valves per cylinder.
The powertrain is installed leaning forwards at an angle of 59°. This is a result of the front-mounted drive system and the vehicle design. In the event of a front-end impact, the powertrain slides underneath the floor of the vehicle, leaving the body to deform freely.
To implement a co-ordinated and economically efficient production process, it was decided that the direct injection diesel and the gasoline versions of the engine would share a common basic configuration.
The maximum power of this engine is 66kw (90hp) at 4200rpm and its maximum torque is 180Nm at 2000rpm.
- Cylinder Block, Cylinders, Crankcase and Main Bearing Structure
- Crankshaft, Torsional Vibration Damper, Flexplate
- Connecting Rod, Bearings
- Piston, Pin and Rings, Cylinder Head and Ports
- Camshafts, Valve Train and Cam Cover