porsche rotor "holes cast in" phenomenon

[Greg Johnson]

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