Originally Posted by jmonier
Just about everything about the N54 is different from the N52 used in the 328 and 2006 325 and 330 including the block construction (aluminum with cast iron liners vs aluminum/magnesium).
So does anyone know why the switch from Al/Mg to just Al block. I heard there were some issues with the early Al/Mg engines. Al/Mg alloys tend to be a more durable and better cooling performance. So why the change to just AL was it becuase of the those early issues?