Rotors, rotors. Other lists, fora, BBs have been all over this.
Let me elucidate:
There ARE bad rotors being sold. There are several ways they are
failing, and several causes.
Some have the rivets failing, such that the brass bit goes flailing
around inside the cap with disastrous consequence.
Some are failing "electrically" by arcing through the plastic so that
the HT spark is grounding through to the distributor shaft. Some
brands seem more prone to do this than others. Some folks are adding
a drop of epoxy to hold the rivet on. As vendors are sourcing from
many different manufacturers and labeling it as their own, it becomes
difficult to declare Brand X is good or bad.
My considerable experience has been to avoid the shiny hard plastic
ones often seen in the newer Lucas green boxes. These are apparently
also marketed by Intermotor, and others. They don't fit well as they
are tight on the shaft. The tracking is very hard to see, but it is there.
The tracking problem is exacerbated by people running electronic
ignitions and opening their plug gap from the usual .028 to .040ish.
The HT spark will look for the path of least resistance, you want
that to be across the plug gap, but if the rotor to shaft is easier,
you will arc. And once the path is "blazed", the spark will continue
to go that way. Also, the hard plastic rotors seem a little tall for
Pertronix people, and they are often filed to fit.
Caution.... commercial content ahead.
I carry very, very good rotors. I have not had a single failure in 4
years and I've sold many hundreds of them. I carry them to every LBC
event I attend. I send large quantities to some notable shops. They
are under 3 bucks. They are made in Italy... I believe by Bremi. They
are a different looking plastic than the others. They say "Remove to
oil" on them, and the rivet is a different style and does not get
loose and change timing like the others. They may be what rockauto
(who doesn't stock a single part) sells, I have no idea.
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