porsche rotor "holes cast in" phenomenon

[Luke Rickert]

from what I know of materials science and fracture mechanics, the cast
holes would be better than drilled, but the smaller holes are much more
likely the propagate cracks than larger ones.

luke

Greg Johnson wrote:
>
> Chris
>
> Still commonly accepted.  In fact the website of one the "big brake" perveyors says: "Holes are4mm diameter as opposed competitor's units with drilled 8mm holes which are more prone to hairline cracking underrepeated heavy braking applications. {Porsche is the only company utilizing a special casting process where they form the holes in the mold which precludes disturbing the metal grain flow during the drilling process}."
>
> Greg Johnson
>
> Message: 3
> Date: Tue, 27 Nov 2001 16:33:00 -0500 (EST)
> From: Chris Covington <malth at umich.edu>
> Subject: porsche rotor "holes cast in" phenomenon
>
> Was this a myth dispelled or is it still commonly acccepted?
>
> Chris
> '91 200q20v