David. I thought I would try to consolidate what everyones been saying.

First. You need two items to run a rotory valve engine in reverse.

1. a reverse crankshaft
and
2. a pusher prop that now pulls because the engine is rotating in reverse.

Second. Just turning around the front housing, not 90, but 180 does nothing as far as the rotation of the engine. The only benefit is that the engine exhausts on the opposite side.