What is bmw m 20?

BMW M20 is a straight-six engine produced by BMW from 1977 to 1993. It was produced in various displacements ranging from 2.0 to 2.7 liters. The M20 engine features an aluminum cylinder head and cast iron block. It has a single overhead camshaft and hydraulic lash adjusters which eliminates the need for valve adjustments. The engine is equipped with Bosch fuel injection and ignition system. The M20 engine was used in a variety of BMW models including the 3-Series, 5-Series, 6-Series, and 7-Series. It is known for its durability and is a popular choice for engine swaps and performance upgrades.