Consider the following:
Normal-wound coil:
(X is first layer along the core)
(Y is second layer along the core)
(Z is third layer along the core)
-------------
ZYX | XYZ
ZYX | XYZ
ZYX | XYZ
-------------
Spiral-wound coil:
(X is first spiral from center to outside)
(Y is second spiral from center to outside)
(Z is third spiral from center to outside)
-------------
XXX | XXX
YYY | YYY
ZZZ | ZZZ
-------------
I've run across someone that claims greater output from spiral-wound coils, as compared to normal-wound coils, but they didn't actually provide any comparative test-results in their plans.
Has anyone here experimented with spiral-wound coils?
A coil of your description will have lower distributed capacitance thand the standard layer-wound construction. There are some high-voltage AC distribution transformers wound using this construction.
Lentz law:
You can see that the orientation of the coil in the picture above, directs the electromagnet directly at the magnetic souce. This causes maximum resistance when power is drawn from the coil. I suggest that a spiral coil such as the Tesla coil would make the ideal alternator coil.
When power is drawn from a spiral coil that is oreinted towards a magnet for magnetic induction to take place; when the coil creates an electromagnet, the magnetic field will mainly follow in the direction of the layers of wire. In other words, the opposing magnetic field would still be created, but it would be directed away from the magnetic source. This I believe will reduce the magnetic drag of a standard alternator.