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RE: Ignition Interference

To: "'Brian Sanborn'" <sanborn@net1plus.com>
Subject: RE: Ignition Interference
From: Randall Young <ryoung@navcomtech.com>
Date: Fri, 2 Jul 1999 09:46:35 -0700
Cc: Triumph List <triumphs@autox.team.net>
Organization: Navcom Technology, Inc
Brian :

My experience has been that the original generator makes far more 
electrical noise than the high tension wires (there is a suppression 
resistor built into the distributor cap, which helps a great deal).  Get a 
0.1mfd 600v mica or ceramic type capacitor at Radio Shack (electrolytics 
are no good for filtering RF).  Connect it from the generator output (NOT 
the field) to ground, right on the back of the generator.  My generator had 
a nut for the spade lug terminal, so I put one end of the cap under that 
nut, and the other under the head of one of the bolts that hold the 
generator together. (BTW if you mistakenly put the cap on the field lead, 
it will eventually destroy the contacts in the voltage regulator.)

Also, there used to be 'premium' plug wires available that had solid wire, 
but a resistor inside the (molded) plug boot.  I got mine from J.C. Whitney 
many years ago, but I've seen them in Pep Boys.  They've lasted as long as 
I've had the car (15 years ?), and look like they'll last much longer. 
 J.Z. Witless gave a lifetime warranty.

BTW, the original wires were stranded copper, with resistors in the plug 
boots.  My experience has been that resistor wires burn out quickly inside 
the distributor cap, but then my ignition isn't exactly stock.

I believe resistor plugs should be an acceptable substitute for resistor 
wires.  I wouldn't bother doing both unless one isn't enough.  RFI 
suppression tends to be something of a black art, so what works for one 
person may fail for another.

There is, of course, a great deal more that _can_ be done, including things 
like a fully shielded high tension circuit, ground straps for the hood, 
inline filters for the generator/alternator, etc.  but these aren't usually 
necessary for broadcast radio.

Another thing that sometimes (rarely) makes a difference is a new condenser 
in the dizzy.

Randall
59 TR3A "daily driver wanna be"

On Friday, July 02, 1999 6:15 AM, Brian Sanborn [SMTP:sanborn@net1plus.com] 
wrote:
>
> Thanks Sumner,
>
> I think that's a good plan.  Buying the AutoZone wire and cutting it 
myself
> sounds good.   That way I can keep the plug boots that are on the car.
>
> Do I have to change to resistor plugs as well... and Brad Kahler 
suggested
> some sort of noise suppression capacitor.
>
> Any thoughts?
>
> Brian Sanborn
> 62 TR4          CT16260L  - Groton,  MA
>
> My TR4 Restoration Web Site
> http://www.net1plus.com/users/sanborn/Home.html (Big Update on 6/13/99)
> E-Mail: sanborn@net1plus.com
>
> -----Original Message-----
> From: Sumner Weisman <sweisman@gis.net>
> To: sanborn@net1plus.com <sanborn@net1plus.com>
> Cc: Triumphs <triumphs@autox.team.net>
> Date: Friday, July 02, 1999 9:05 AM
> Subject: Ignition Interference
>
>
> >Hi Brian,
> >
> >Probably the po installed stranded copper ignition wires rather than
> >resistance wires.  The tradeoffs are:  copper wires will last for many
> >years, and probably will give you a hotter spark.  But -- they will 
allow
> >your ignition to not only interfere with your radio, but also to radios 
in
> >cars near you as well.  Resistance wires will suppress radio 
interference,
> >but my experience has been that they will only last 2 or 3 years and 
then
> >have to be replaced.  I used to buy them from the "big 3" but now I just
> get
> >them from Auto Zone and cut them to size myself.
> >
> >Replacing the wires will solve your problem, and it's not a bad 
solution.
> >When doing it, don't forget the coil-to-distributor wire.
> >
> >Also, make sure the radio case is well grounded.
> >
> >Sumner Weisman
> >62 TR3B
> >
> >
> >Hi Gang,
> >
> >I am so glad to be asking these questions instead of the " where does my
> >camshaft go" questions.
> >
> >I installed a new radio in the TR4.  One of those 70's retro ones from
> >Kenwood.  The reception and sound is perfect with engine not running.
> >Some noises start coming at idle but when the engine is revved to normal
> >level the radio signal is overcome by ignition noise.
> >
> >I have changed to negative ground.  And the ignition wires are as they
> were
> >when I bought the car last year... but they show no sign of wear.... and
> >they look very period with orange-red rubber boots on the plugs.
> >
> >I am using the NGK BP6ES plugs which I am guessing are not resistor type
> >plugs.  What do I have to do to get the noise out.
> >
> >I remember this battle has an original TR4 owner.
> >
> >Brian Sanborn
> >62 TR4          CT16260L  - Groton,  MA
> >
> >My TR4 Restoration Web Site
> >http://www.net1plus.com/users/sanborn/Home.html (Big Update on 6/13/99)
> >E-Mail:
> >
> >
> >
> >
> 

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