Before commissioning Description of the engine Thanks to their fully electronic control sys- tem for controlling the injection quantity and injection timing via solenoid valves, these are particularly low-emission en- gines. The OM 501 LA and OM 502 LA engines are water-cooled 4-stroke direct injection diesel engines. The 6 or 8 cylinders are arranged in a 90° V and have separate fuel-injection pumps (unit pumps) with a short high- pressure fuel injection line to the multihole injection nozzle located centrally in rela- tion to the combustion chamber. The unit pumps are mounted directly on the crank- case and is driven by the camshaft.
Each cylinder has two inlet valves and two ex- haust valves. The control system comprises an engine- resident control unit, an engine control (MR) with integrated heat exchanger for cooling by means of the forward fuel flow and an application-related control unit, a vehicle control (FR) or an adaptation mod- ule (ADM), all interconnected via the Con- troller Area Network (CAN). 2 The OM 501 LA and OM 502 LA engines are equipped with an exhaust gas turbo- charger and a charge-air cooler as stand- ard. The engine can be optionally equipped with an engine brake* (throttle valve and constantly-open throttle valves) and a flame-start system. 27 General remarks