Posted by Jeff Olson on November 05, 2002 at 20:31:35 from 12.77.25.134
In Reply to: anybody know anything about M90 engine? posted by Justin in C'ville on November 05, 2002 at 19:41:09:
I used to have a non-federalized '79 'Euro' 635CSI RUST bucket. Really impressive power, great acceleration, easily a 140 MPH car. The US car just does not compare except for the rust-proofing. The way the 6-series was intended to be except for the rust.
You may want to check www.m535i.org. I think there were specifications there as well?
This paraphrased from Jeremy Walton's book, BMW 6 Series Enthusiast Companion:
The M90 is a designation from the M49 racing engines of the 70's supposedly in reference to an oversize bore finish.
93.4mm X 84 mm bore and stroke
3543 cc displacement
9.3:1 compression ratio(some sources say 10:1)
218 bhp @ 5200 rpm
224 lb-ft torque @ 4000 rpm
Spread of 191 lb-ft torque between 2000 rpm and 5900 rpm.
Bosch L-Jetronic with fuel/air metering 'Euro ECU' to take advantage of the bigger bore and shorter stroke.
Mine had the stock BMW factory exhaust with NO converter and big 50mm dual pipes front to back. Also had the stock 3:07 open differential and close-ratio 'dogleg' 5-speed. Really GREAT engine and drivetrain!
I believe this is the same set-up in the E12 M535i except for LSD. The LSD was optional on the 635CSI, it REALLY needed one standard. All that power and weight on the stock skinny little 195/70/14 tires at 140 mph on the Autobahn!
Jeff