Fastest 2 wheeled steam powered vehicle? Probably

from http://www.jalopyjournal.com/forum/showpost.php?p=5860024&postcount=13533 is the tank of superheated water that when the valve is opened flashes to steam, and being locked down to the rail, propels the vehicle it was attached to into a crash test concrete block.

Imagine the speed this could attain if it wasn't pushing a car into a wall