DIS Explainations

[Egil Kvaleberg]

On Sun, 22 Mar 1998, you wrote:

> I can offer no clues as to why the waste spark only consumes 20-30% of
> the spark energy in a DIS ignition system that fires two plugs at once.

The clue is that one cylinder is at atmospheric pressure (or thereabouts)
whereas the other plug is at compression pressure. Air is an insulator,
the effect of which increases with pressure as you note. This means that
the resistance at the plug exposed to low pressure is much less than the
resistance at plug exposed to high pressure. Basic Ohms law tells us that
the voltage drop over the high pressure plug will be much higher.  Since
the current is the same, the energy at the high pressure will be higher.

Egil
-- 
Email: egil at kvaleberg.no  Voice: +47 22523641, 92022780 Fax: +47 22525899
Snail: Egil Kvaleberg, Husebybakken 14A, 0379 Oslo, Norway
URL:   http://www.kvaleberg.com/           PGP: finger:egil at kvaleberg.com