05-04-2022, 09:51 PM
A year or two ago at a public car show one of the 12v Bradfords had been fitted with a 6v coil. The igniton had been left on and whilst several curious were examining the unusual motor the coil exploded...... It definitely had oil in it!
I dont know when PCBs arrived, probably in the 1950s along with many other nasties. Presumably transformers were oil cooled before PCBs. And presumably when used the PCB concentartion was more like 100%.
With a normal mixture very little is required to ignite. I have a handbook for a Pratt and Whitney Double Wasp and the plug gap is just .012". Big gaps and fancy voltages are requird for weak mixes as moderns and as erratically occur at idle and starting. From extensive everyday experience with my RP I suspect plug gap influences effective advance.
I dont know when PCBs arrived, probably in the 1950s along with many other nasties. Presumably transformers were oil cooled before PCBs. And presumably when used the PCB concentartion was more like 100%.
With a normal mixture very little is required to ignite. I have a handbook for a Pratt and Whitney Double Wasp and the plug gap is just .012". Big gaps and fancy voltages are requird for weak mixes as moderns and as erratically occur at idle and starting. From extensive everyday experience with my RP I suspect plug gap influences effective advance.