Lock the welder

Rotary engine video

[youtube=http://www.youtube.com/watch?v=6BCgl2uumlI&feature=player_detailpage]   This is a cool example of how a rotary engine works. I saw one of my friends had it posted on facebook so I thought I'd show it here. Two things I don't understand as of now:  1. lubrication to the apex seals?  2. Why does the combustion want to turn the rotor? I see no reason for it to turn when combustion occurs.  I will find out the answers and post them.