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      02-19-2016, 12:35 AM   #188
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Drives: BMW
Join Date: Mar 2012
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Originally Posted by jwzimm
Originally Posted by Boss330 View Post
Automated manufacturing and assembly is easier without a woodruff key. The manufacturing of the hub and sprocket is simpler because there is no need to align the teeth on the sprockets with a groove for the key. The hub/crank snout can be mounted without the need to be in a particular position. During assembly the crank is correctly positioned relative to the cams. Then the robots can place the timing chain, sprocket and hub straight on the crank. no need to position a woodruff key before putting the hub and sprocket in position. Mounting of the sprocket on the hub is also much easier, in an automated process, without a woodruff key.

The design, IMO, is purely there because of assembly requirements. Not because it's a "better" design for strength...
In addition, it has been speculated that this design can function as a "money-shift" fuse. That could be an intentional design.
Agree that my wording "purely for assembly" was a bit to conclusive

However, I feel that the crank design of the new modular engines, with a machined sprocket integrated in the crank, kind of weakens the argument regarding money shifting. The new design does not allow slippage so it does not have that "function" designed into the valve drivetrain...

So it seems they do not think slippage is a necessary safe guard, at least not on the new modular engines...
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