[Jeff NJ]

Originally Posted by Iciclehead

I have had the same question and for me, with the floating rotors, the new ones are not cheap, particularly if you want the Porsche rotors.

From what I read in the factory manuals, they are supposed to be Blanchard ground...technically referred to as Rotary Surface Grinding, quickly removes stock from one side of a part that is typically too large to be Double-Disc Ground. I went to a machine shop and they looked at me like I had three heads when I asked if they did Blanchard grinding.

If I recall, the original finish on my rotors (new) was obviously ground in some way, I also think that the amount removed is very small, just enough to take the lip off and to remove any waves, so I do think that the chamfer on the holes would largely remain.

Most shops with a disc lathe take off way too much, usually they take it down to just over the minimum disk thickness, partly to make sure they get all the grooves out (not necessary) and partly as a way to sell you unneeded services.

There are places on the web that do Blanchard grinding, the Turbo brakes are coming off my car to get it ready to sell, I may well send them out to be ground and will report back on any findings should I do that.

Dennis

My clutch flywheel was Blanchard ground by my local pcar indy shop. Maybe a shop that can re-surface a flywheel can do the same for a rotor?