Date: Mon, 16 Dec 1996 21:50:20 -0800
From: Mike West <mwest@cdsnet.net>
Subject: Points and Dwell

Points and Gapping or "Dwell".

Thanks to Michael Butler for pointing out I'd glossed over
this function a bit too fast in "Coils n' points"

The points control the field of the secondary winding in the coil
and this could go on indefinitely within reason.
Like burning up the points.

Here's the part I didn't mention, it's when the points open, that
the coil gets desperate for a way out. There's no ground thru the points to
bleed to.

In the micro or millisecond after the points open is when the coil fires the
spark plug.

So, the length of time the points are closed is the length of time the
field has to build it's charge.

 Too much is not good for points, and too little is not good for building
the fire with.

That length of time the points are closed and open is the "dwell" and is
controlled by the gap in the points.

If the points are closed too long, they don't get the spark to the plug at
the right time for the piston.

The spark shows up to late , well the piston left without it!  :-)

Same as a too retarded timing on the dizzy spindle and low power to you.

If the points are gapped too much, the spark will get there too soon.
Notice how pinging is often the result of the points gap?


So it might be worth your while to go check it, as long as you're
out there changing oil anyway.   :-)

 west    there's still more dark out there!