28-09-2023, 01:53 PM
Hi
There have been several versions of the "spark improver" over the years, including the roadside fix of wiring a coat button (remember them) in series with the main HT lead to create a spark gap.
There is a grain of truth in their use, in that if you have a worn out engine with oil/carbon fouled plugs the spark gap helps prevent the HT energy prematurely leaking away into the resistance of the plug. Instead there is a momentary delay until the coil has built up enough voltage to spark over properly.
I have a feeling that some spark plugs were made with a built-in extra series gap within the insulator, but at the moment I can't find a reference.
There have been several versions of the "spark improver" over the years, including the roadside fix of wiring a coat button (remember them) in series with the main HT lead to create a spark gap.
There is a grain of truth in their use, in that if you have a worn out engine with oil/carbon fouled plugs the spark gap helps prevent the HT energy prematurely leaking away into the resistance of the plug. Instead there is a momentary delay until the coil has built up enough voltage to spark over properly.
I have a feeling that some spark plugs were made with a built-in extra series gap within the insulator, but at the moment I can't find a reference.