On Sat, 3 Sep 2005 13:44:05 -0400, "hutchtoo" <hutchtoo@gmail.com>
wrote:

>Tegger's FAQs has references to dwell meters - e.g for testing the coil. I
>have never heard of a dwell meter before and they aren't widely available
>from what I can tell..
>

In the old mechanical breaker points ignition systems, dwell angle is
the angle of rotation of the distributor through which the mechanical
points are "closed. The points must remain closed for a sufficient
time to store energy in the coil sufficient to produce a good, hot
spark at the plug when the points open. In a four cylinder engine,
dwell angle is typically around 60 degrees.

There is an equivalent measurement in an electronoic ignition system
that is usually called dwell, but it is not properly dwell in the old
contact points sense. This quantity is electronically controlled. I am
not sure what an old fashioned dwell meter would be measuring in a
modern electronic ignition engine. However, I do not think it would be
useful information. There is typically no way to make adjustments on
most electronic ignition systems anyway.

Hope this helps.

Elliot Richmond
Freelance Science Writer and Editor