IGNITION
From: Randall Young
<ryoung_at_NAVCOMTECH.COM
Subject: RE: Ignition
timing? Pinking (pinging)
There are several
places in the TR2/3 factory literature where it mentions setting the timing so
that pinking is just barely audible when accelerating in high gear, with heavy
throttle, from a low speed. My
experience is that this method works fairly well on any engine, with the
caveats that I like to retard just slightly from that position, so that the
pinking is not audible at all; and you may need to adjust again in warmer
weather.
I honestly feel that
this method is _more_ accurate (in terms of what the engine actually needs
given it's current condition, available fuel, etc.) than just blindly setting
the timing to a factory published number. To do better will require actually
measuring engine performance, with timed acceleration runs or a rolling road
(dynamometer), etc.
From: "Mr. Finespanner" <MrFinespanner_at_prodigy.net
Subject: vacuum advance testing--calibration check
If you take Mark's good advice and purchase a vacuum device to use in checking your advance unit you can get a good idea of how close to "spot on" the action is. A good vacuum gauge is calibrated in inches of mercury. On the Lucas vacuum units there is a three-part number in addition to the part number; that is, three numbers separated by two dots. The first number is inches of mercury at which the advance action begins, the second is inches of mercury at which the pulling stops, and the third number is total degrees of advance for the unit. You can check the spring movement against the gauge calibration, using the first two numbers, to see how close your unit is to spec.
From: Randall Young <ryoung_at_navcomtech.com
What is the relative resistance of a ballasted coil vs. a
non ballasted one. I need to use a ballast coil and want to make sure the one I
have is the correct one
Coils with an internal ballast (ie not requiring an external ballast)
have a DC resistance of around 3-4 ohms.
Coils requiring an external ballast are about 1/2 that value, around 1.2
- 1.8 ohms.
From: Randall Young randallyoung_at_earthlink.net
Electronic ignitions
fall into two broad categories : those that work by inductive kickback in the
coil (as points do); and those that generate a relatively high voltage then use
the coil as a step-up transformer.
The first category
(sometimes called point amplifiers) are, in effect, just electronic switches
that replace the function of the points. The Pertronix, Crane XR700, and most
OEM auto electronic ignitions fall into this category. The XR700 instructions
are at
http://64.90.9.168/cranecams/pdf/90002000a.pdf
The second category
(sometimes called capacitive discharge or CDI) includes the MSD line, the Crane
XR3000, and many OEM motorcycle electronic ignitions.
IMO the big advantage
of the first type is it's relative simplicity, which should translate to lower
cost and better reliability. CDIs are considerably more complicated, but at
least in theory offer faster spark rise times (important for firing fouled
plugs, hence their use in 2-cycle motorcycles), and the ability to do fancy
things (like the multiple sparks per firing of the MSD 6 series).
From: Randall Young
<ryoung_at_NAVCOMTECH.COM
I currently have the
Crane XR 700 Electronic ignition on my TR6. I am also running a Lucas Sports
Coil. I noticed in the most recent Moss catalog that the Lucas Sports Coil
works with non-ballasted ignition systems only. On the same page it shows a Crane Ignition Coil which complements
the Crane XR-700 Ignition kit and includes a ballast resistor. I'm getting more
and more confused as to what I should be using.
The Lucas Sports coil
(at least the most common variety) does not use an external ballast resistor
when operated with either points or the XR700.
The Crane coil does use an external ballast when used with either points
or the XR700. The XR700 will work fine
with either coil, it's the coil that determines whether the ballast resistor is
needed or not.
If you were using a
coil that needed a ballast but didn't have one, the engine would run fine until
the XR700 overheated, then it would not run at all.
However, I'm not certain
what the XR700 would do if you had an unneeded ballast resistor. Most likely
the same as with points, ie hard starting and poor fuel mileage. To find out if
you have ballast, connect a jumper wire between the coil '-' terminal (which
should have the yellow wire from the XR700) and ground. Turn the ignition key on, but don't start
the engine. Now measure the voltage
across the coil. If it's around 12 volts, then there is no ballast
present. If it's around 6-8 volts,
there is either a ballast present, or you have a really bad connection
somewhere.
Note that this
discussion does not necessarily apply to other electronic ignitions, the Crane
XR3000 for instance requires an external ballast type coil, used with no
ballast.
From: Bill Katz <bkatz_at_handsonresearch.com
Here's how mine is
wired:
·
Solid black
from Pertronix to original solid white wire.
·
Black/white
wire from Pertronix to coil.
·
Original
white/black wire to other side of coil.
·
New jumper
wire from chassis ground to same side of coil as original white/black.
BTW, I crimped on
spade connectors to the Pertronix leads, so if I have to revert to points, the original
connectors are still intact.
From: Blue One Hundred
<international_investor_at_yahoo.com
The Pertronix works
MUCH better than points, giving a more even exhaust firing, better power and
mileage. The added
benefit is never having to adjust the points, timing, & carb settings,
which I had to do every 1,000 miles or so before.
Some basics:
1) Is your coil oriented
correctly? With points, the car will
fire no matter which way the coil is hooked up to the ignition &
distributor. With the pertronix, it
won't work if the + and - terminals are hooked up backwards. If you have an old british coil with CB
& SW terminals, chuck it. It's hard
to tell which is the + or negative terminal because the brits, in all their
majesty, would put CB and SW on alternate terminals depending on if it was for
a positive or negative ground car. Get
one of those new lucas sport coils (which is marked + and -)
2) Sometimes the
pertronix kits are a little off with timing - you may have to move your
distributor around a bit. Turn the car
over with a timing light and see how far off you are from TDC - you may be off
a fair amount - the first time I installed the pertronix, the timing was off
about 20 degrees. I rotated the
distributor around a bit and all was hunky dory.
If you put in the
effort once, you'll never have to change the points again. Having two healeays myself, the pertronix
has made maintaining the two cars an occasional pleasure, rather than a regular
chore....
From: Erik Quackenbush <erik_at_midwestfilter.com
Subject: Re: Pertronix reliability
Pertronix had a bad batch of adhesive in their
magnetic collars a few years ago and people here have long memories. New ones work beautifully, so don't buy one
that's been sitting on the shelf for a long time.
I've installed multiple Pertronix and Crane XR-700
units in different cars over the years. I really prefer the Pertronix. The
Crane takes longer to install and is a pain to fit and align properly. It has a
cheap aluminum bracket that holds the optical sensor and is a trial to adjust
properly. It also adds a modern looking box that looks out of place in a
classic engine compartment.
When properly set up both units appear to perform about
the same. Neither unit produces a killer spark like an MSD but they do
outperform points.
From: Dave Massey <105671.471_at_compuserve.com
Subject: RE: Pertronix reliability
One advantage to the magnetic pick-up variety over
the optical pickup is immunity to dirt. It is possible to get enough grease,
oil and dirt on the optical device to render it unreliable whereas the magnetic
pick-up device would have to be fouled with metal shavings to effect it. But
the optical interrupter with radial slots will accommodate distributor wobble
better than anything else.
“I love the Petronix,
no more dwell drift! And if you put the right connectors on the cable ends, you
can swap the points back in without changing a thing if you need to. Only
problem I had was a serious change in distributor position to get the timing
right.”
“If you have an old
worn distributor with sloppy bushings - it won't affect the accurate
performance of the pertronix whereas with points sloppy bushings and worn
shafts can put your timing and dwell all over the place. “
From: Fred Meyer <kerowako_at_attbi.com
Pertronix p/n LU-165P12,
installation problems were (aside from the vague installation instructions):
1. Had to move the distributor drive 60 deg
CW to get the distributor pointed back to the original orientation. (could be
solved with a re-clocked magnetic pickup/rotor).
2. Wire feed grommet out of distributor body,
supplied in kit, was very poor fit.
It would seem they designed this for a Jag DM6 variation, and although it'll
work in a Healey application, there are a few rough spots. After getting over
the installation headache, all is well and fine.
For DM6 distributor
(positive ground), the model number is "Pertronix - LU165P12 (DM6A).
The neg grnd version I believe is LU165N12. I spoke to Pertronix's personally
at 1-800-827-3758,
“Ordering directly
through Pertronix is NOT the way to go! They charge full retail (as does Moss).
$100 or more. Better to find a retailer that carries Pertronix at a discounted
price, usually between $60 and $80, and order it through them. In fact, when I
called Pertronix that's what they suggested to me.”
From: "Michael D.
Porter" <mporter_at_zianet.com
These cannot be gapped
by traditional means. Toolmakers are supplying plastic gap checkers which do no
damage.
Bosch WR7BP, (platinum
plug), Randall
From: "Richard J.
Hockert, Esq." <rjh.co_at_worldnet.att.net
Subject: Re: Am I
running too cold with Champion N9YCs?
The correct Champion
plug for the 6 cylinder cars is RN12YC.
The next hotter plug is RN11YC.
Your plugs are dark brown because they are running too hot and the
ceramic is beginning to burn. Are the
electrodes disappearing?
My understanding is
that an R plug is used only to reduce interference with radios and other
electronic devices in the car. It is
not supposed to have any effect on the ignition system components. Using a more
powerful coil will allow you to increase the gap of the plugs but should not
have an effect on the dizzy cap or plug caps.
Here is a link to an article on spark plugs
that Richard J. Hockert wrote for AH Mag