Pulsed Capacitor Engines...

Not to slight Tinkerbell in any way, I would say that static single-to-three phase converters using capacitors could be considered "pulsed capacitor discharge electrical engine" power supplies.

The Edwin Gray engine motor has too much hype surrounding it to be credible.

That said, high voltage or frequency might allow for a smaller size motor than a conventional motor of the same horsepower; but that's not the meaning of efficiency.

Yes, starting from the construction (that could be rather expensive) to the result, one should ask if it could be a feasable method to build electric machines.

I think the idea quite good, but... at what price and for what result .

still, if get some time to I may try something in this area to test it...

Gray's invention is a motor, not an engine. An engine burns fuel.

This invention is a very complicated solution (and not very workable, on first glance through the patent) to a non-existent problem. There is no reason to think that the very brief pulses from a capacitive discharge would produce an electric motor of any higher efficiency that the current state of the art. On the other hand, there are many reasons to believe that efficiency would be lower to much lower. There are too many conversions in the flow as compared with a conventional motor.

The patent does not make clear what problem this motor is intended to solve. Without evidence to the contrary, it would appear to be a very low efficiency, complicated motor -- several steps backward rather than a step forward.

The issue that has kept electric cars out of the mainstream is not the motors (which are remarkably simple, smooth running, highly efficient, and reliable devices) but the batteries (which, even using the best of the current state of the art -- such as the lithium polymer batteries in the Volt) are heavy and very expensive.