Originally Posted by Juiced46
There is one thread about the N54 being forged in earlier years, then multiple other threads of people assuming it was forged from that one post, then it spread like wildfire on assumptions. How do I know? I work for BMW. I have disassesmbled BOTH the N54 and N55 motor many times. They are not forged, even the early ones, they were not forged. I have spoken to numerous BMW engineers about this as well to confirm. They also confirmed there was never a Forged piston/rod assembly in an N54 production motor. I know my facts, other then reading what people assume on the internet. I have first hand experience. If you read the thread of the one owners N54 bottom end build where he says the pistons are forged, you can clearly see they are not. Take it for what its worth.
The only thing that was forged was the crank...
The new M135i has the forged crank aswell... With an N55 engine