Di Pietro created an engine which runs on air .The Di Pietro motor concept is based on a rotary piston. Different from existing rotary engines, the Di Pietro motor uses a simple cylindrical rotary piston (shaft driver) which rolls, without any friction, inside the cylindrical stator. The space between stator and rotor is divided in 6 expansion chambers by pivoting dividers. These dividers follow the motion of the shaft driver as it rolls around the stator wall. The motor shown is effectively a 6 cylinder expansion motor.
in his website he says
* We have verification of its performance
* We have patents issued
* It has outstanding efficiency
* It has constant high torque
* It has low parts count
* It has low number of moving parts
* It is compact and light
* It has virtually no friction
* It has virtually no vibration
* It has smooth speed control characteristics
* Only 1 PSI of pressure is needed to overcame the friction
THAT'S CORRECT ONLY 1 PSI !!
here are the vehicles he converted to air powered vehicles
Air engine in Boat
found a video of a car he converted on youtube
