Originally Posted by Hans
I'm not interested in "halfassing" the job one bit. I want it done right, however reviewing other resources I did not see that it was required or needed to seal the rotor plate to the rotor housing.
I just think about it this way - you've got two machined surfaces, like any other in the car. Except, unlike other surfaces in the car (almost all of which we take the time to put a gasket on), this one is responsible not only for basic sealing, but for sealing under pressure - typically around 7 PSI worth. Not a whole lot, but enough that if there'* any gap in the seal, you're going to be blowing boost into your engine compartment.
So, for the extra 3 minutes it takes (plus some extra care, as noted above), I don't see the point in not adding the sealant.
And, as a counter point, my blower had evidence of some sealer on this surface when I took it apart... a very thin layer. Very thin. A little carb cleaner and a rag (along with some muscle) was all it took to clean it off... but it was there.
Just my opinion.