Originally Posted by Mad Dragon
The N54 is an aluminum version of the N52; the construction of the blocks is virtually identical. There's no argument here; I've had all 3 engines apart.
N52: open deck, 2-piece block, electric water pump
N54: open deck, 2-piece block, electric water pump
M54: closed deck, one-piece block, belt-driven water pump
I think you're missing the overall point.
I'm not disagreeing about the point you're making, as it is true.
Still, the 2 engines have enough differences to conclude that the N54 is not simply an aluminum version of the N52.
This TT engine is more a combination of the old engine and the new engine.
It is not the same engine with just turbo's put on, as you're implying, but never directly saying.
The materials are not the same, bore and stroke not the same.
I believe the cylinder linings are not the same.
Then, the top end is completely different.
To say, or imply, that the turbo engine is the same as the N52, except for being made of aluminum is incorrect. Also, I'm speaking of the entire engine as well, not just the block.