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Originally Posted by kcpaz
This doesn't justify the need for an intermediate shaft at all. Obviously there are a LOT of other successful engines out there that don't use intermediate shafts to accomplish proper operation.
Also, can anyone tell me why there was a need to drive the cams from opposite ends of the engine? Again, it seems unnecessarily overcomplicated.
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Its impossible to make my point here on the forums.. And its nothing but hypothetical anyway.
Practical application and time will illustrate the weaknesses of the "IMS-less" engines, as with every engine throughout time.
What people generally don't understand is the "lay shaft" as an intermediate drive for the valve train has been in place since the mid 1950s with Porsche engines. This is depicted here in this image of a 1955 Porsche Spyder engine I was working with a few years ago.. That shaft below the crank is the lay shaft, it transmitted mechanical energy through bevel gears and shafts up to the exhaust camshafts, that then drove another shaft and bevel gears to drive the intake cam, just like an M96, the only difference is chains Vs. bevel gears.
Notice the plain bearings, not a roller bearing like the M96.
Shaft that is driven by bevel gears, driving exhaust camshafts
Exhaust cam and bevel gear to drive intake cam
The moral of the story is the fact that Porsche used an IMS style design since 1955 when this engine was produced, the IMS was NOT a new design for the M96, but the roller bearing support Vs. plain bearing support was. The IMS isn't the reason for engine failures.
We'll see just how wise removing the IMS was in time.. We are already beginning internal development on the "new" engines.