<VV> carbon tracking

[djtcz at comcast.net]

----- Original Message ----- 
original message 
From: "lewisrishel" <lewrish at sbcglobal.net> 

Subject: Re: <VV> carbon tracking 

Mention was made recently hereon about carbon tracking in the distributor 
cap. If you understand that the original caps supplied by Generous Motors 
are black because they have someting called lampblack (which is a carbon 
bypproduct) in them to make them black, then you can see that tracking is 
very likely to happen eventually. And more likely in the moist, hot southern 
places like that long narrow state that extends down toward cigar land, as 
well as the northern one with the million water holes for ice fishing, and 
also the humid areas in the rusty bible belt, plus the places below the 
salty sea level ober der in die Nederlaanndt. 
So, what is the cure. There are several manufacturers of caps without 
lampblack, Niehoff is one, these caps are available in blue, tan and grey 
and perhaps other colors. They have copper or brass contacts inside, not 
that cheapie aluminium crap the general uses, I prefer Brass, which will be 
a lifetime cap, and will never carbon track. ya pays yer money, and ya takes 
yer cherch. 

_______________________________________________ 


I can't speak for the recipe of 1960s black caps, although it doesn't take much carbon black to make a polymer conductive to static electricity. 
Sometimes less than 10% 
http://www.cabot-corp.com/wcm/download/en-us/cc/CA%20General%20Processing%20Guide-English326665.pdf 

I have had a few non-black ignition components develop carbon tracks. It seemed to be a surface phenomenon, developing on surfaces that were damp or a little oily enough to misfire for a while ( I pictured moisture beading up on the oily surface, then the spark passing by, charring the "plastic.) I used a dremel to grind out the tracks in my Hemi Peugeot's expensive mile-long spark plug connectors (http://www.franzose.de/flexxtrader/data/img/big/72002.jpg) , and restore full performance. 

Echlin/Accel made a big deal about their tan colored high performance caps and coil noses being made from some Alkyd material. 
Electrical codes specify a minimum spacing between electrical connectors because air can be pretty conductive compared to real insulating materials. 
Over 1/4 inch spacing required at just a few hundred volts, if I recall correctly . 

I think at some point the cap material may not be the limit, and sparks can only be contained with longer surface distances, either from sheer size, or those extra ribs ( used on spark plugs, too) . 
http://img383.imageshack.us/img383/2329/img2613fs2.jpg