I agree with Soul Surfer [8D] completely, except it's more like .00001% instead of 10%. A flywheel in the form of a uniform steel disk has a maximum rim speed in the neighborhood of 300 to 500 m/s. (Any mechanical engineer can tell you, the size of the flywheel doesn't matter, the rim speed is the same for any shape and material.) Max rim speed for a flywheel made of carbon nanotubes with the theoretical maximum strength might be in the neighborhood of 1 km/s. To be generous, you might guess that the max rim speed is the speed of sound in the material, which is about 8,000 m/s for Kevlar. The speed of light is 300,000,000 m/s.
So your motors can't be made of atoms. Maybe they're atomic scale motors, and the armatures are electrons. Still, you're on shaky ground assuming that relativity works at that scale. GR doesn't work at the quantum scale. In
my own model, the Higgs force alters the path of light zillions of times more strongly than gravity does. Anything that bends light in Euclidean space causes the warp of Minkowski space time. So GR needs to be modified to include the warp due to the Higgs force if it is to work at the atomic scale.