13 Sep 2003, 20:01, Roy J. Tellason (1:270/615), wrote to Tom Walker:

Hi Roy.
.....................

 TW>> They have a smooth porcelin Insulator instead of the ribbed ones 
 TW>> most plugs have.

 RJT> Duh!  They don't know what the reason is for those ribs,  I 
 RJT> guess?

Seems like many do not know the reason for those ribs.  The 'ribs' is a
patent of "Champion", way back before rubber boots were thought
of or invented, and plain old flat uninsulated wire ran from the
distributor to the spark plugs (Ford's Model 'A').  Spark plugs had a habit
of collecting dust, much like what you now find on the HV wiring of TVs due
to the corona effect.  On cool damp mornings, no one's car would start
until you popped the hood and wiped the damp dust from the plugs.  Champion
invented and patented the ribs to provide a longer path for the spark to
cross getting from the cap to the base, just like powerline insulators (and
for the same reason).  As ignition voltages got higher, other manufacturers
made their plug insulators longer, but that had two adverse side effects,
first, the additional porcelain increased cost, and second, the taller
plugs no longer fit the then available socket wrenches.  This gave the
independent Champion a big edge on the market.
.............

 TW>> Well Guess What. One of the plug wire boots slipped off form all 
 TW>> the vibration. Something that almost never happens, And he limped
 TW>> in in Last place.

I've run into that MANY times over the years, on all kinds of engines, and
for that reason prefer to NOT have the rubber boots.  The terminal of the
wire MUST fit the plug cap, and MUST snap on properly, otherwise the wire
WILL fall off (eventually).  The rubber boot merely masks a poor fitting
wire connector.  Same problem with the latching plastic covers on many
computer connectors, although the plastic is latched, there's NO way of
knowing how well the wire terminal inside that plastic fits.

Mercury Outboard has the BEST wire connector, and in my opinion the ONLY
fully reliable one.  It is a coil spring, and HAS to be wound onto the plug
cap.  To remove it, it has to be un-wound, it CANNOT be pulled off.
............................

 RJT> For most of what I do Autolite seems to be quite satisfactory.  And 
 RJT> I *won't* use Champion plugs at all...

Same here!   


     Good luck...  M.

--- Msged/386 TE 06 (pre)