desperate need for info on sync gaps

	hi i read that post a week ago about the 6"x24" coil with 28 gua wire and
12/30 nst and was amazed to hear that it got 3 foot sparks. i have a 6x24
with 24gua , a 4x24 with 24 gua , and as of tonight i have a 6x24 with 28
gua. i have lots of 12 gua wire which was what he said he used for the pri,
but the design also called for  a 120bps sync rotary gap which i feel is
was to hard to find info about. i know all basic construction methods for
rotary but dont have the slightest idea of how to modify a standard ac
motor to syncronous operation. i have a vacume cleaner motor, a very well
made brushless ( can you use brushless) 1/6 hp 3500 rpm 60hz motor, and a
blender moter of unknown value. is it possible and if so worthwhile to
modify them to sync operation because i already built a  async rotary with
poor results although that motor died due to arcs to its shaft and may be
possible to repair but i havent looked into it yet. and i do also have 
		ps. what exactly are the characteristics of a sync moter ie. is it in
time with the 60 hz that it and the xfmr run off so you have to place the
electrodes in precise orientation to the brushes or something so they
connect just as the polarity is about to reverse and discharge the cap ? ?
or am i completely lost. i do have acess to many tools cus my dad is
mechanic and wood worker so modifying to motor might be fairly easy. oh and
about that 12/30 coil design would it run properly on a static gap like the
one i currently have 
	very much thanks in advance Chester Lowrey