Diesel engines (Audi 80 B4)

AUDI vehicles are equipped with two types of diesel engines: a 1.9-litre turbocharged diesel engine (TD) with a power output of 55 kW and a 1.9-litre turbocharged diesel engine with direct fuel injection (TDI) with a power output of 66 kW.

Cars produced before 6/92 were equipped with a 1.9 l TD engine, which provided a torque of 150 Nm at 2200 rpm. Starting from 7/92, an improved version of this engine was installed, which provided a torque of 150 Nm at 2400 rpm.

As for the 1.9 l TDI engine, since the end of 1993, an improved version has been installed on AUDI cars, which has increased torque, amounting to 202 Nm at 1900 rpm. Before that, cars were equipped with the same engine, but its torque was 182 Nm at 2300 rpm. On cars with an automatic transmission, an improved version of the engine has been installed since 7/93.

The cylinder block of diesel engines is made of gray cast iron. The crankshaft is located in the lower part of the cylinder block, and the cylinders are located in the upper part (four in a row). The cylinders are surrounded by coolant circulation channels.

The crankshaft of the engines has five main bearings. This means that each crankpin has a support on the right and left.

If you look in the direction of the car's movement, then in cars with a manual gearbox, there is a flywheel on the rear end of the crankshaft, to which the driven clutch disk is pressed. Torque from the engine is transmitted by the gearbox. In cars with an automatic gearbox, instead of a flywheel, a thin driven clutch disk is installed on the crankshaft together with a torque converter.



At the opposite end of the crankshaft is a drive gear and a belt pulley with a vibration damper.

The light metal pistons have a steel thermoregulating plate. The TD engine pistons have a combustion chamber cavity in the shape of the number 8. This cavity provides improved pressure distribution of gases formed during combustion of the fuel-air mixture (see illustration 3.0a).



The TDI engine pistons have an omega "O" shaped combustion chamber cavity (see illustration 3.0b).



The designation of pistons 1/2 and 3/4 corresponds to different versions of pistons installed on the engine. In pistons of cylinders 1 and 2, the recesses of the exhaust valves are located in the direction of movement, and in pistons of cylinders 3 and 4, the recesses are on the back side. The inlet and outlet valves are arranged in mirror image. At the same time, to ensure better heat distribution, the exhaust valves, which have a shell of hard metal (stellite), are located closer to the ends of the engine.







(The original article is located on the online resource audimanual.ru)