I built a "v-twin" air motor.

In 2002/2003, my fabrication colleague and I built this small air engine/motor as an alternative to the high RPM/low torque pneumatic motors manufactured at the time.

The motor used two 1 inch bore 2 inch stroke linear actuators and could operate at pressures between ~50psi to ~160psi. We ran it on a torque-meter once but I no longer have the data.