SpudFiles

I'm planning on running a 9v through an ignition coil and into a homemade sparkplug for my hybrid, and I have tested it and it works fine. However, since it will be running through a somewhat long ignition cable and I also just want more power, I decided to use 2 9 volts. My question is, do I set up the 9 volts in parallel or in series? (i was thinking series)

If you are getting a decent spark, I would keep things as is. You won't be using an "ignition cable" that's too long to make a negative difference. Long cables affect situations where there are large current draws. With high voltage spark generation, you have extremely low current draw.

Just keep your ignition wires seperated from each other and avoid them criss-crossing before they come together at your gaps.

Is it ok if they cross before the ignition coil, because they are attachhed into one cable with electrical tape. (also, why is this?)

There is a risk the spark will jump from wire to wire at the criss-cross point, thus "shorting" the spark beofre it reached the chamber gaps. For the same reason, using lamp cord or other close twin lead cable almost always leads to ignition troubles.

If they need to cross, seperate them as far as possible. Just design it where they don't have to cross.

Ok it goes like this: batteries -> double cable-> ignition coil-> 2 separate wires-> gap

I dont think having the wires in the double cable together is a problem, were talking about the gap wires?

that should work fine.