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Re: scout plugs, CB question



LATE BREAKING NEWS: "Neff, Matthew John - MBA" <NEFMJ124@domain.elided> wins
the 40 million dollar lottery and says:

>Quick question for you- I know you run an MSD in your traveller

Correction... *used* to.

>and I was
>wondering what plugs you use.  MSD tech types first told me to use the stock
>heat range, and then told me to use a colder plug...  Don't know who to
>believe.

I don't see any reason to change the heat range of your spark plugs just
because you install a different ignition source.  I suppose the person you
spoke to at MSD was basing his suggestion on the consideration that the MSD
unit is capable of firing the plug through deposits that would otherwise
cause a less powerful ignition system to misfire.

Consider this... The heat range of the plug is determined by the design
features of the plug and not the ignition system.  The rate at which a
spark plug transfers heat from the electrode tip to the head is how the
rating is ultimately established.  A cold plug will transfer more heat and
thus run cooler.  It will therefore be less able to keep from being fouled
by combustion deposits, but *if* you had a very powerful ignition system,
this fouling might otherwise be overcome.

But there's no reason to change from the standard plug temperature unless
you have a very specific reason to do so.  Let say you started idling your
truck a lot in sub-zero temperatures.  In that case you might want to go a
step hotter on your plugs to help them from becoming fouled.  If you were
to start running your engine at full throttle operation all day long, then
you might consider a step cooler plug to help prevent the plug electrode
from glowing and contributing to pre-ignition.  For normal driving you
should just stick with normal plugs!

Personally I prefer platinum plugs simply because the platinum electrodes
last longer and hold their gap better than conventional spark plug
materials.  I like the original Bosch platinum plugs and I use those in all
my vehicles.

>Also, I know  you run a CB radio with a nearly identical ignition
>set up as mine-  what are you doing to prevent noise?   thanks a bunch.

The ignition noise from the MSD is going to be a problem unless your CB has
appropriate circuitry to reduce the noise.  My Uniden has noise blanker
circuitry which helped considerably at the cost of a slight loss of
reception range.

I'm using just a breaker-point distributor with a Pertronix-Ignitor now and
the ignition noise is much less than with the MSD.  But then the Pertronix
isn't firing the spark plug multiple times over 20 degrees of crank
rotation, so that obnoxious "buzzing" sound interference isn't present in
the CB any longer.

Regards,

John L.
-------------------------------------------------------------------------- 
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