[Nobbc] Petronix ignition testing

[Paige, Dean]

Lots of talk about the small stuff. Yadda yadda yadda! I first put a
Pertronix in my 73 TR-6 in the early 90's. First unit had a flaw in the
magnet ring. It came apart. Changes were made by the manufacturer.
Second installation has served me well for the 20 years it has now been
in operation. Of course timing and carbs required adjustment. Standard
coil has been in continuous use. Never noticed any change in Tach
readings, though I think I'm due for a Tach and speedo overhaul. With a
mechanical Tach I just don't see how the reading could change unless the
Tach was failing. Electric Tach? I guess there could be issues. Anyhow
the difference in performance was and still is substantial. No more
points slippage, no more having to check the timing regularly and most
important a smooth and notable power increase throughout the rpm range.

Go for the Pertronix. For the price you pay it is more than worth it.

I hate to be missing the rides lately. The TR-6 flywheel ring gear is
toast. Looks like it was a starter problem. The front surface of the
ring gear was crunched to the point that the starter gear will no longer
engage in the ring gear. Pulling the tranny in the next couple of weeks.
Will replace the ring gear and install a gear reduction starter. Also
seriously considering a Toyota 5 speed tranny for the beast. Hope to be
on the road again early spring. So many other project in the works. So
little time! I should probably just join the rides in the Jag VDP. Just
not the same as the roadster though.

On the upside it looks like I will retire in July with a pension that
provides 80% of my salary til I croak. Plus the City is offering a
substantial management buyout for those of us topped out long in the
tooth managers. All that and a hunk of dough in deferred income should
keep me happy. Will likely do some consulting along the way too. Never
in my wildest dream would I have thought that I would work for any one
entity for over 20 years. Doc says I'm in hale and hardy and I expect to
keep it that way. I really do need to get out from behind this desk and
spend the rest of my days in the great outdoors. Quite the quantum leap
though and a little intimidating.

Deano



-----Original Message-----
From: nobbc-bounces at autox.team.net [mailto:nobbc-bounces at autox.team.net]
On Behalf Of Gregory Tatarian
Sent: Wednesday, February 17, 2010 8:11 AM
To: North Bay British Car Club
Subject: Re: [Nobbc] Petronix ignition testing

I have a few observations and some experiences with Pertronix:

First, the ignition timing will change after conversion. The trigger
point of the unit is different than with contact points, and most likely
your timing will be REALLY advanced, so keep that in mind.

Next, the coil resistance is very important, and must be matched to the
existing wiring in the car and the type of Pertronix used (Ignitor vs.
Ignitor II vx. Ignitor III). Specifically, cars with ballast resistance
wires will affect the coil resistance selection, as will the conversion
unit. Most of the conversion units for our cars are Ignitor (not II or
III), but new distributors come with II or III versions, so be careful
there.

One effect of changing your ballast wire/coil configuration is your
tachometer; using a 1.5 ohm coil instead of a 3.0 ohm coil after removal
of the ballast wire will often result in a tachometer that does not read
correctly - often 2x the actual reading. In many cases, your tachometer
will bounce around no matter which coil/wire/Ignitor combination is
selected.
This is due to the older type of triggering used in older cars. If you
have Smiths gauges, for example, and have an RVI movement tach, you will
be likely to have issues. If you have a later RVC tach, it will almost
certainly perform properly, due to the compatibility in circuitry with
electronic ignition. Old tachs can be converted, but that's easier done
in England than here, though there are one or two shops that handle the
conversion.

What I have found is that it is generally safer to use a 3.0 ohm coil
with our without a ballast wire and have the Pertronix see extra
resistance than to use a 1.5 ohm coil without a ballast wire, even if
that is the preferred configuration, unless you convert your tach.

There are other considerations when converting to Pertronix, and we can
cover those at the tech session if that's a popular subject.

FWIW, I have Pertronix units on the Elan and TR6, and they function
flawlessly, and have since being installed. I don't keep a spare set of
points, but I do have a spare Pertronix. I've had plenty of points and
condensors fail or wear prematurely, so always used to keep spares of
those, although they are cheaper in comparison; I just always expect
that something will fail, and I'm not disappointed when it does. Hmm.
Cynical of me...

Spark on!

Greg Tatarian

On Wed, Feb 17, 2010 at 7:50 AM, Walter Kilchherr
<wkilch at sbcglobal.net>wrote:

> I've heard nothing but good about Pertronics, it improved my Sprites
> performance. BUT, I've heard you can kill them by leaving the ignition

> on too long without the engine running. It does hurt to have the old
> parts in your car just in case.
>
> Walter
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