I begin the rebuild of the 2.5L M54B25 from my friend's 2005 E46 325ci!

He bought a replacement engine to try and swap in because the original with 230k miles was burning lots of oil and was down on power. However, the replacement with 120k wasn't in good shape and the cylinders were warped. The original engine looked to be in better shape, so we decided to rebuild this one on a budget to get another few years of life out of the engine.

It's pretty clear why the engine was burning oil based on the state of the bottom end, but it's fixable.