Vehicle Description
1977 BMW 528I. Born in Germany. Now, 40 years since, she's
completely restored and sports a rare German 1980 M90 engine and
drivetrain; never driven in the rain. M90 engine history: The M90
was the first road going BMW engine with 3.5 litre displacement.
Originally this engine was used to test if the M88 engine was
reliable with the narrow web spacing of 6.6mm. This means that this
engine has exactly the same bore and stroke as the M88 and is
directly related. However instead of a DOHC cylinder head with 24
valves, BMW used the SOHC cylinder head with 12 valves. The use of
an electronically controlled fuel management system (Bosch
LE-Jetronic) allowed a slightly higher compression of 9.3:1.
Strictly, the M90 engine is not an M production engine although the
E12 ///M535I in which it is used is a real M car. Until 1981, the
M90 engine was used for the early 635CSI and the very rare and
delectable E12 ///M535I from 1980. (The Beginning of a Legacy - A
BMW Motor Evolution By tschultz