General information about the engine (BMW 5 Series E12)

On BMW 5-series models "518", "520", "520i" a four-cylinder engine was installed on the "520" models from the 1978 model year, "520i", "525", "525i", "528", "52Bi", "535i" a six-cylinder engine was used. Both the four- and six-cylinder engines used a valve timing mechanism with a V-shaped arrangement of valves, with an overhead camshaft.

Main technical characteristics of engines of cars produced in 1972-1977.

* Since the 1976 model year, the rated net power of the engine with the K-Jetronic fuel injection system is 125 hp at 5700 rpm, the maximum torque is 17.5 kgf·m at 4350 rpm.

Main technical characteristics of engines of cars produced in 1977-1987.

Since the 1982 model year, the following engine specifications have been changed:

• Compression ratio: "518": 9.5; "5181": 9,3; "525i": 9,6; "528i": 9,3.
• Nominal power "net", kW (hp) / at crankshaft speed, rpm: "518": 66 (90) / 5500; "518i": 75 (102)/5800; "525i": 110 (150)/5500; "528i": 135 (184)/ 5800.
• Maximum torque, kgf·m: "518" or "518i": 14.0; "525i": 21,5; "5281": 24,0.
• Maximum permissible crankshaft speed for engines of all models, rpm: 6400.

Longitudinal section of the 6-cylinder engine BMW "525" and "528"

The original article is available on the website BMWman.ru