Here are some tech tips to help get spark into your early battery and coil systems of the day. Many strange attempts, some downright silly to make a spark with a battery and a coil. Ignition systems of days gone by can be described as high tension where ignition is caused by a high voltage jumping across a gap(Sparkplug) or low tension where much lower voltages are used and ignition is caused by mechanically snapping two contacts apart inside the combustion chamber. More on this to follow.
Attempts at high tension systems usually took the form of some sort of distributor with a set of points or two and a condenser,or in early attempts a set of contacts inside the cylinder that switched current through a coil with an iron core and made a spark when they separated, or by a buzz coil like Henry Ford used.
Here is a great idea from American Bosch for the model T. It spares us from those cantankerous buzz coils that can cause asymetric firing or no firing, and the often wimpy flywheel magneto. It gives a hot spark at low cranking (often by hand) speeds and will consistently fire every 90 degrees giving smooth operation.
Some worked well in their heyday, others made one think what if anything was going through the designers minds, like hiding the condenser stuffed in a paper can full of hot tar with the coil. Obviously they were not communicating with those in the next cubicle who will actually be operating and maintaining these systems. Everyone knows that condensers never need replacing,especially after 50-75 years right? Only to bite the restorer in the bum when he or she hangs a new coil in the circuit and there is no place for the condenser inside the distributor where it should be. Sometimes much headscratching to find where the blessed condenser is hidden. They come in all shapes and sizes creating challenges for replacement. Sometimes to fit in skinny spaces we can place two or more capacitors of a fraction of the desired value in parallel as total capacitance is additive when devices are connected in parallel. A 0.22MFD 400 volt device may be too thick, but we can sometimes place two skinnier 0.11 MFD 400 volt devices in parallel to get 0.22MFD. Some parts were made of pot metal which has suicidal tendencies, high voltage and primary shorts can be invisible, intermittent and very annoying. For these and many other noseeums, bunyips and sasquatches tormenting these brave souls we call restorers we salute you!