Broken M96 crankshaft- X-51s fail too!

[blue2000s]

Originally Posted by Lil bastard

There are several things to consider when using pressed metal tech to form a part. Pressed metal pieces perform best under compressive force and much less so under tensile force or torque (twisting). This is what surprises me about using this tech for a crank, seems to be one of the least suitable environment.

But, I'm no Porsche engineer, so they must know something I don't. Either that, or the bean counters have veto power over the engineers, which come to think of it, maybe isn't all that much a stretch.

But, with CNCing being all the rage today, it would seem that they could get a cost (and reliability) effective alternative going that route with a forged billet.

Then again, a little perspective may be in order - this is the 1st crank failure that I'm aware of and it occured in an extreme application (racing). Still, it was the X-51 part. I can more easily see the stock crank using pressed metal, but am really astounded to see it adopted for the premium, race purpose part.

Cutting billet parts is expensive because of the time and wasted material. Definitely more expensive than powdered metal.