speaking of arcing plug wires...

[B Vibert]

Ok, here's my theory.
Since it's easier for a high voltage arc to start from a sharp point
the boots eliminate any local spots around the boot where an arc is
more likely to blow through the insulation of a "naked" boot by
equalizing the high E-field stress around it.

Burl Vibert
1987 5kcstq
Kingston, Ontario



"Livolsi, Stephane" wrote:
>
> What is up with those metal caps on the spark plug boots anyway?
>
> What purpose do they serve other than to provide an easier path for the
> spark to get to the head?