Bob,
I would determine exactly what type of ignition system you
have in your car first, then move on from there.
A little history:
All Federal spec. Spitfires from (about) 1975-on were fitted with
electronic ignition.
The first system used was the "Opus" electronic
ignition, in conjunction with the Lucas 45DE4 distributor. This
system consisted of an electronic amplifier module that was built
into the base of the distributor assembly. It can be identified by
this appendage on the dizzy body, which will have 4 wires coming
from it, going to a 3 pin connector, and then to into the wiring
harness near where the oil pressure sensor wire breaks out of the
harness. The electronics were potted in a green epoxy-like
compound which is visible on one exterior face of the module.
The "Opus" system was notoriously unreliable, and I believe there
are no working examples remaining. Mine failed within the first
2 years after buying the car new. These were fitted up to the
"early" 1979 models (chrome bumper). If you have one of these,
replace it immediately, and preserve the unit. A working
example is certainly rare and may be worth a fortune to an
originality freak ;-)
The light finally flickered on at Lucas (pun intended) and
they switched to the "Constant Energy Electronic Ignition" system
for the last cars, and for warranty replacement of the "Opus" units.
The CEI was a much more reliable system and working units still
survive. It can be identified by the separate amplifier module
(probably) mounted on the bulkhead (firewall) near the brake/clutch
master cylinders. Lucas finally figured out that the engine heat
was cooking the earlier unit's electronics. The Amp module will
have a label that says Lucas, AB14 electronic ignition amplifier
and another number (like 47261A) on it. It has 2 wires going
to the coil and a cable with a red wire and a blue wire inside
going to the distributor. I would not replace this unit unless
there is a compelling reason to do so.
So, what other possibilities might you have?
Points- and a compatible distributor, possibly obtained from an
early car. Most likely fitted to replace a failed Opus unit.
Easily identified by looking under the distributor cap.
Aftermarket Electronic Ignition- (external amplifier module)
-Made by Piranha; Black plastic module housing with picture of
fish showing its big pointy teeth.
-Made by Lumenition; Silver metal finned module with brand name
cast into the housing.
-Made by Crane; Black metal finned module with "Crane" on label.
Early units have "Allison" instead of Crane on the label.
All of these units will have a cable from the module to the
distributor, and individual wires from the module to the ignition
coil. The location of the module will vary depending on the
installer's preference. They all work well, but the distributor
cable on the Piranha is pretty fragile.
Aftermarket Electronic Ignition- (self contained)
-Made by Pertronix; This unit is housed entirely inside the
distributor cap. I have no direct experience with these, but
those who have them seem to like them.
-Maybe some other system that I am not familiar with.
So now you have figured out which system you have, do you want to
change?
All else being equal, there is no significant _performance_
advantage to an electronic ignition over points IMHO. Having said
that; Yes, the distributors fitted to later US Spits have advance
curves tailored for low emissions rather than power (as already
mentioned). Yes, electronic ignitions will rectify timing "scatter"
that you get with a well worn points type distributor. Yes, electronic
systems have relatively long dwell and are virtually maintenance free.
These issues are peripheral to [electronic vs. points] as are
hotter coils, ballasted vs. non (coils), dual vs. single points,
vacuum vs. purely centrifugal advance etc. etc. So many choices...
I'm sure you'll find no shortage of dissenting opinions on the above.
Hope this helps. Back to (intermittent) lurk mode.
Electrically yours,
-Bob
Bob B. wrote:
> I have a '79 Spit and am slowly doing little things to try to boost
> performance. I've seen a recent post by a lister who did kind of an
> electrical tune up. My question is what should I replace/upgrade since I
> know nothing has been done in a long time on the car: plugs, ignition
> wires, coil, and "stuff" in the distributor (this is where I'm really
> fuzzy)??
>
> How about electronic ignition? In the recent issue of Spitfire Magazine
> there was a recommendation to upgrade to electronic ignition. When I look
> at the car's specs in the Haynes manual it looks to me like it says I
> already have "pointless electronic ignition" or something like that (I don't
> have the manual in front of me). Would getting one of those Crane
> electronic ignition kits be an upgrade or something different from what's in
> the car now.
>
--
LBC'ing U,
Bob (& Spitfires)
[digest mode]
http://home.att.net/~stan.part
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