[Healeys] Points question..

[Bob Spidell]

AFAIK, points are made of solid tungsten (although, with our 'cheap at all costs' society that may not be true any 
more).  Theoretically, you can file them down to almost nothing (but I wouldn't).  Filing of points is mostly to get you 
home, where you can install a fresh set.

The condensor--it's a capacitor--is an integral part of the primary ignition system.  It affects the way the coil is 
charged and discharged, though I don't have the knowledge to totally explain it (in electronics it's known as a 'TC 
circuit').  The points in the fuel pump are just used as an on-off switch; timing isn't critical.  The diode is known as 
a 'flywheel diode' because it shunts the back-current induced when the electromagnetic field in the pump body 
collapses.  Come to think of it, if you put a diode across the ignition points the 'back-current' from the coil would 
flow through them instead of providing a spark  at the plugs (and the diode would burn out the very first time, since 
there isn't a diode made that can withstand 20K volts or more that I know of).

Bob


On 4/10/2011 5:37 AM, Tom wrote:
> How often can a set of points be cleaned-up?  Are the points coated with
> something like platinum that I need to be careful that I don't file off?
>
> Another question...  if the fuel pumps use diodes across the points to keep
> the points from burning, why do the distributors still use condensors?
>
> - Tom
>
>


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Bob Spidell           San Jose, CA            bspidell at comcast.net

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