[mikefocke]

because of course Porsche designed the 2009 and later Boxster/Cayman/911 engines without an Intermediate shaft. So it could be done. Why wasn't it way back when?

And if I recall the story, it was because the engineers were familiar with that design and the company was strapped for cash so they were reusing every bit of engineering in an attempt to get a new car out the door quick and cheap. And it isn't as if all IMSs fail (far from it) or that they all fail quickly so any fool could know the design was faulty. Consider that every 911 and Boxster would use this engine in '96/'97, it isn't as if the engineers wanted it to have problems...they were betting the company on the M96 engine.

We are now looking at the problem with the benefit of 20-20 hindsight and about 16-18 years of experience (from initial design of the engine till now). It seems obvious to us, but I'll bet few at the time were seeing the potential for problems especially faced with the economic realities of the time.

Every design is a compromise between the available time, budget, schedule, the technology of the time, the knowledge of the designer, the limits placed on the testing, the wishes of the thought-to-be potential customer, manufacturing costs, expected maintenance costs, internal company politics, etc. Get any one wrong and you lose the company if you were Porsche in the '90s.

As one who once had total product specification responsibility, it isn't that easy to get it right. Nor is it obvious it was right until perhaps years later. In my case 6 years after I wrote the specification and millions of investment dollars later...

Plus what you'd choose today in materials might well be very different than the materials available in the 1992 time frame which was probably about the time the M96 engine was being designed. New materials and new knowledge about how to use those materials are available now that weren't available to the designers back then.