Hi Dan,
I have some followup questions regarding the Sports Coil conversion you
describe below. (My car is a 76 - real late one at that).
The 76 wiring diagram (I assume you have one) shows a pink-white wire
from a white wire on the starter switch. This pink-white is then
"transformed" into a white-yellow wire via part #9 - "ballast resistor
wire".
My coil is configured as follows (I am reasonably sure it is the stock
configuration). A white-yellow wire from the harness is in parallel with
a wire wrapped in a "shellacqued shoelace" (for lack of a better
description). Both these wires are joined with a solderless lucar
connector and are attached to a "ceramic" thing which is attached to the
coil mount bracket. Then a blue wire goes from this ceramic piece to the
positive terminal on the coil.
Does this seem like a stock set up? Is the shoelace wire the resistor
wire? Or is the ceramic piece the thing which adds the resistance? How
do I convert this set up accept the Lucas Sport coil? The sport coil has
no ceramic external pieice like the Lucas coil in there now.
Thanks for any help you might provide!
Peter Zaborski
76 TR6 (CF58310 UO)
Calgary AB Canada
> -----Original Message-----
> From: DANMAS@aol.com [SMTP:DANMAS@aol.com]
> Sent: Wednesday, September 10, 1997 8:40 AM
> To: suhring@lancnews.infi.net; triumphs@autox.team.net
> Subject: Re: Lucas Sports Coil
>
> In a message dated 97-09-10 07:47:26 EDT, suhring@lancnews.infi.net
> (scott
> suhring) writes:
>
> > I am planning on upgrading my standard Lucas coil to the Lucas
> > sports coil (as well as tuning the distributor, etc.). Please help
> > me understand the difference between a balast and a non-balast
> coil.
> > Also, how are these wired differently when going from a balast coil
> > to a non-balast coil.
>
> Scott:
>
> Basically, A ballasted coil is designed to produce full spark output
> with
> approximately 9 volts on the input (+ terminal). A non ballast coil is
> designed to produce the same spark output, but with the full 12 volts
> on the
> input.
>
> With a non-ballast coil, the input to the coil is the same, 12 volts,
> whether
> the engine is running, or being cranked by the starter motor. With a
> ballast
> coil, the starter relay by-passes the ballast resister when the
> starter motor
> is spinning the engine, and applies the full 12 volts to the coil.
> Since the
> coil is designed to provide full spark with 9 volts, the application
> of the
> full 12 volts produces a much hotter spark, which is an aid in
> starting.
> After the engine starts, and the starter motor is off, the coil
> voltage is
> dropped to 9 volts, and the coil output is the same as for a
> non-ballast
> coil. The reason the ballast type coil is not run at the full 12
> volts, for a
> hotter spark, is to prevent damage to both the coil and the points.
>
> With a non-ballast coil, power is applied to the coil directly from
> the
> ignition switch, via a white wire. Power to the ballast coil comes
> from the
> the ignition switch to the resistance wire, and then to the coil. When
> the
> starter relay operates, power is applied from the battery, via a brown
> wire,
> to the starter relay, and through the starter relay via a white/yellow
> wire
> to the coil. This shorts out the resistor wire, by placing 12 volts on
> both
> ends of the wire. With the same voltage on both ends, no current
> flows, so no
> heat is generated. The current flow is shunted around the resistor
> wire. This
> bypassing of the resistor wire places the full 12 volts on the coil.
>
> As for the modifications required to switch from a ballast coil to a
> non-ballast coil, it couldn't be simpler - just run a wire from the
> most
> convenient white wire you can find (probably at the fuse box),
> directly to
> the + terminal of the coil (of course, all the rules of good wiring
> practice
> shouild be used). No need to remove the resistance wire, because it
> will now
> be constantly bypassed, just as it was before when cranking.
>
> Now here's the good news for you - your '70 TR6 does not have a
> ballast
> resister, they were used only from '74 and later. As I understand it,
> the
> modifications made to these cars to meet the environmental concerns
> made them
> hard to start, so the ballast type coil was used to get the extra hot
> spark
> during starting, since starting places the most stringent demands on
> the
> ignition system.
>
> For a more detailed explaination of igntion systems in general, see:
>
> http://www.vtr.org/maintain/ignition.html
>
> Hope this clears it up a little for you. If anything is still not
> clear, let
> me know, and I will try to clear it up for you.
>
> Dan Masters,
> Alcoa, TN
>
> '71 TR6---------3000mile/year driver, fully restored
> '71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion
> - see:
> http://www.sky.net/~boballen/mg/Masters/
> '74 MGBGT---3000mile/year driver, original condition
> '68 MGBGT---organ donor for the '74
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