Originally Posted by Dieselmd
Skycat, with me coming from an iron block closed-deck 4g63t and seeing that you chaps are pushing these cars to their limits, would you put a safe/reliable HP/TQ number to the N54?
it is very interesting, that you make mention of the non iron, open-deck block
of the N54.
With all the speculation surrounding the pistons, I would have thought there would be more discussion regarding the inherent potential for failure, as a result of the block design.
Looking at images of the deck, it would seem there is very little distance between cylinder walls.
Given the open deck nature of the block and the minimal cylinder to cylinder clearance, there is a possibility at a certain power level the cylinder liners will start to "walk".
If they do, then it is bye bye head gasket.
This is of course total speculation.
The N54 power plant could be good for another 125-150 wheel horsepower or it could fall over within the next 50.
Unfortunately without "solid" information from BMW, there is no real way to know the horsepower limit of the N54.
Of course following the spectacular failure of an engine, the subsequent pull down and close inspection, will provide some very useful data.
Though it sucks to be the owner of that particular vehicle.