Plugs 101...after school

[camron at worldaccessnet.com (Camron D. Crouse)]

Larry Fry wrote:

>  The only thing (besides gap size) on a plug
>that will affect a spark is the 'edges' on the electrodes.  A spark will
>jump between two sharp edges more easily than between two radiused or flat
>surfaces.  This means that it requires less voltage to spark over the same
>gap with nice, new edges...and a marginal ignition system may find it easier
>to fire this plug than an old, worn, rounded-electrode plug.
>

My local German parts shop (FLGAPS ?) has a counter-top promotional 
demonstration unit for Denso Iridium spark plugs <www.densoiridium.com>
It features a "regular" plug and an "Iridium" 0.4mm electrode plug.  You 
push down on a button on the front of the demo unit, and live arcing 
occurs on each plug simultaneously for comparison. The smaller electrode 
plug has a *much* more focused arc, and it claims to use less power to 
spark it, and is way more consistent.

Con: they're like US16 bucks each.  Yowza.


- Camron from Vancouver, WA USA
   '86.5 Black 16V 2.0L