The BMW M20 is an I6 piston engine. Introduced in the 1971 BMW 3.0Si, it was produced for 30 years, powering the E21 and E30 3-Series, as well as E12 and E34 5-Series cars. It was the "little brother" to the larger BMW M30 engine with displacements ranging from 2.0 to 2.7 liters.
One notable member of the M20 family is the "eta" version. It was designed for better fuel economy and saw the company through the 1970s energy crisis. All M20s used Bosch K-Jetronic fuel injection.
M20B20
Applications:
M20B23
Applications:
M20B25
The M20B25 featured a 12-valve SOHC head, 84 mm (3.3 in) bore, and 75 mm (3 in) stroke.
Applications:
M20B27
The 2.7 L M20B27 was designed for efficiency (thus the e in 325e). It had an 84 mm (3.3 in) bore and 81 mm (3.2 in) stroke for a total displacement of 2693 cc. Output was just 121 hp (90.2 kW) and 170 ft.lbf (230.5 Nm), but fuel efficiency was fairly good for the period.
Applications:
See also
