Hi Mike,
It is definitely NOT necessary to replace the distributor, as long as
yours functions properly. In fact, Pertronix units, like many other
electronic ignition systems, often extend the useful life of older
dizzys because they aren't as affected by a worn shaft bushing, which
causes points bounce. Also, there is no longer any wear on the cam,
which now only serves as a locator for the reluctor (as I recall the
term for the part).
In most cases, you will be able to keep your existing coil if it's
30,000 volts or higher - a Lucas Gold Coil is fine. The Pertronix 40,000
volt coils are nice. You won't really know how your tachometer reacts
until you wire up the Pertronix. My personal approach would be to
install the conversion kit, then see how the system works. If you have
to change the coil, remove the ballast resistor wire, or have the tacho
converted, you can do those only if needed. I don't know how Draeger
tachos are triggered, but I assume it's current pulse triggered. Newer
tachos, say after 1972, were voltage pulse triggered, and work properly
with electronic ignition systems.
By the way, I use my unconverted RVI tach in the Elan with a Pertronix,
a ballast wire, and a 3.0 ohm coil. The tach bounces, but not
excessively, and I haven't been motivated yet to have it converted.
Having said that, I want to eventually replace my dizzy with a Pertronix
with an Ignitor II that is sitting on my shelf; that will require
conversion of my tach to work properly, since I have to bypass the
ballast wire and use a 1.5 ohm coil with that unit.
Bottom line is you don't have to go with replacing everything at once;
try the Ignitor, see how it works. If more changes are needed, you can
do that immediately, or swap back to points until you sort out the other
details.
There's lots of information on the Pertronix site, including the following:
What type of coil can I use with the Ignitor^(TM)? How do I
check my coils resistance? (12V negative ground only)
To determine if your systems coil is compatible with the Ignitor, some
measurements should be taken prior to installation of the Ignitor.
Caution... While performing this test, never leave the ignition switch
on for more than 30 seconds at a time.
Set your voltmeter to a 15 or 20-volt scale. Attach an 18 or 20 AWG
jumper wire from the negative coil terminal to an engine ground. Attach
positive (red) lead of your voltmeter to the positive side of the coil,
and the negative (black) lead to an engine ground. Turn the ignition
switch to the run position. Now read the voltage at the positive coil
terminal. Turn the ignition switch off. If the voltage measured is
approximately 12 volts, no resistance wire is present. A typical
resistance wire will provide 9 - 6 volts.
The next step is to determine the resistance in the primary ignition.
Label the wires attached to the coil terminals and note their
appropriate location. Make sure that the ignition switch is off and
disconnect all wires from the coil. Adjust your meter to the lowest ohm
scale. If you are using an analog style meter make sure to zero the needle.
Measure from the negative terminal to the positive terminal. Write your
measurement down.
Now the maximum system amperage can be determined, divide your voltage
measurement by your coil resistance measurement. This will give you the
system current or amperage.
Four and six cylinder engines should not exceed 4 amps. Eight cylinder
engines should not exceed 8 amps. If the total amperage in your system
is higher than the amount recommended for your application, you should
install a ballast resistor.
Example
Voltage 12
Resistance 1.5
12 / 1.5 = 8
Total amperage 8
Cheers,
Greg Tatarian
On 2/17/2010 10:05 AM, Mike Gianandrea wrote:
> Hey Greg,
>
> I have gotten pretty excited about putting the Pertronics in my TR4,
> but your message sort of takes me back to my original reservations. In
> reading your message, it would seem that replacing the points only is
> only part of the job, thus it would seem that for proper performance,
> one should replace the points, coil, and distributor, is this correct?
> Also, I have Draeger gauges (not sure they read acurately now) in my
> TR4, am I likely to have a problem with these? If I'm going to make a
> change, I prefer to do a complete and correct job, and have my car
> hummin. What are your recommendations?
> ----- Original Message ----- From: "Gregory Tatarian"
> <gtwincams@gmail.com>
> To: "North Bay British Car Club" <nobbc@autox.team.net>
> Sent: Wednesday, February 17, 2010 8:10 AM
> Subject: Re: [Nobbc] Petronix ignition testing
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