E30 Engine Swap

Out with the old, in with the new. This E30 shipped as a 325E which comes with a M20B27 engine. Although its displacement is larger than the standard M20B25, it is a lower-revving, lower-horsepower, economy variant. My goal was to swap the drivetrain components; engine, transmission and rearend, to create a 325is. Getting this engine in place was the first step.

I originally sourced a used M20B25 that turned out to be too fargone to be used. That turned me to CATuned in California where they built me an entire engine and head assembly to drop into my E30.

This may sound like a small feat, but there is a lot of effort required to swap this over. The wiring harness, ECU, gauge cluster, throttle body, AFM, and a laundry list of little parts are needed to complete the swap. Getting the engine into the chassis is the simple part, getting it to run like it was built that way is a bit tougher.