site: http://www.pattakon.com/pattakonOPRE.htmA 500cc two stroke can easily make some 80 Nt*m (8 Kp*m) torque.
At 6000 rpm this torque makes some 50 KW (70 PS).
little youtube vid: http://www.youtube.com/watch?v=L0S3nTc_ogE
I kinda doubt the performance figures, but on the other hand - its a two stroke engine, and if you sum up the stroke of both cranks - it would make a torque like longstroke engine and could achieve mutch higher rpm, but Im just guessing here
This could be the ultimate motorcycle engine