Displacement Up: Power? Not Really
The big news for 1978, and the news that had U.S. enthusiasts chomping at the bit, was that we would get the 3.3-liter (actually 3210cc, 3.2L) M30 engine--the E24 became the 633CSi. Horsepower nudged upward just 1 pony to 177 bhp at 5500 rpm, but torque increased to 196 lb-ft at 4000 rpm. This helped the 1978 633CSi trim its 0-to-60-mph time to 8.3 sec., although 0 to 100 was days off the European version of the same car. The remainder of the drivetrain remained unchanged, as did suspension and brakes.
Air conditioning and leather became standard equipment, and the U.S.-spec E24 remained unchanged until 1980. Owners still busied themselves de-smogging the engines, while the plague of cylinder-head warpage and legal wrangling awaited those who did not.
The 1977 630CSi is both the rarest and the least desirable of any U.S.-specification E24. Of the early four-speed manual cars, the 1978-79 633CSi is far more prevalent but is still rare today.
For many, the big coupe is the ultimate of Munich's driving machines
From the February, 2009 issue of European Car
By Mike Miller