Ok here's the run down of what just happened.
I have a brand new Magnum .91 4 stroke, and Im breaking it in on my Hangar 9 AT-6 Texan.
The prop is a 14x8.

The plane is on a stand, so it has had no contact whatsoever with the ground or anything that could be sucked into the blades.

After running about 1 tank through the engine, I cranked it over again after it cooled. I used a chicken stick with a rubber end.
When I spooled up the engine to full throttle, both sides of the prop seperated at exactly the same place.
The engine reved incredibly high before I was able to shut it down, but actually no more then a second and a half.

Anyone ever had this happen before? Ive seen props throw a blade, but never both ends at exactly the same moment. I wonder if the engine is damaged now.
Thank god no one was in the line of the prop arc when it let go...I still cant find the blades.

Here is a picture below...the scratches are from me trying to get the remains off with a channel lock...before I took the prop off it had no scars anywhere, it was all perfect looking, but without blades.