Quote:
Originally Posted by NISFAN
I would like to think BMW will use displacement to differentiate the S55(??) from N55, and using a specific to S55 longer stroke forged crank would be a sensible way to achieve that.
Cast cranks have made a bit of a resurgence, think it's down to a new process that reduces the porosity.
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Both an increased displacement and forged crank would be sensible and welcomed changes to make the engine both better and more special. Unfortunately those are no longer the driving forces at BMW M. That being said, I certainly would not rule them out.
Despite process, with a similar design, I doubt there is any way to get the same consistency, yield strength nor fatigue resistance from a cast product.