RE: [DML] Re: Spark plugs (was Upgrading the Air Filter)

["John Hervey" <john@xxxxxxxxxxxxxxxx>]

Toby, Thanks for the + 4 Bosch plugs explanation. I knew a little bit about
it but not all.
John Hervey




-----Original Message-----
From: tobyp@xxxxxxxxxxxx [mailto:tobyp@xxxxxxxxxxxx]
Sent: Saturday, December 04, 2004 1:23 AM
To: dmcnews@xxxxxxxxxxxxxxx
Subject: [DML] Re: Spark plugs (was Upgrading the Air Filter)





Andy - Bosch originally developed the Platinum +2 for small general
aviation aircraft to increase reliability and avoid fouling.
Obviously, the plugs are far more important in an airplane than a
car from a safety standpoint.  What they found is that the specific
conditions of the ground prongs were constantly changing as
combustion chamber swirl, carbon build-up, and other factors entered
in.  The spark would jump first to one prong, and then the other.
It was unlikely that both would fail at once, leading to complete
failure of the plug.  Then, under the theory that "more is better",
they added another pair of prongs.  However, the spark only jumps to
one prong on any one firing cycle.  Is it dramatically better from a
strict performance standpoint?  Doubtful.  I will admit that I am
using +4's in all of my cars, and they are always clean and light
tan in color when I check them.  My Ford Explorer has 184K miles on
it, and I have no issues with fouling at all, similar to my Dodge
Intrepid with 132K miles.  The DeLorean seems to like any of the
Bosch Platinum's, and I have +4's in it now.  I talked to a
professional mechanic one time about platinum plugs, and he said
that they should NEVER be used in any car.  I pressed him for an
explanation, and this is what he said:  They are too reliable, and
hardly ever need changing.  This causes people to start to neglect
other areas of maintenance, leading to a general deterioration of
the car.  His theory was that when the normal plugs burned away or
fouled out, the owners would have a general tune-up done, including
all of the other things that you typically do during a tune-up.  In
short ... platinum plugs are too good, and last too long!
Personally, I do all my own maintenance, and don't fall prey to
neglecting anything.

Toby Peterson  VIN 2248 "Winged1"
DeLorean Parts Northwest, LLC
www.delorean-parts.com


--- In dmcnews@xxxxxxxxxxxxxxx, Soma576@xxxx wrote:
> One thing I've wondered about +4 Plugs - it seems to me that all 4
ground wires/electrodes cannot be precisely the same distance from
the center electrode. Since the spark is going to jump the quickest
way it can, only one ground wire will cause the spark for combustion
(the closest one).  How is that any better than a single-wire plug
(besides being more profitable for Bosch)?








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