Converting to electronic ignition
Wednesday, January 5, 2005
I had planned to spend the morning converting the Spitfire to electronic ignition, but it took about ten minutes, so I spent the morning driving round the countryside instead. Its not an especially exciting job, but I've not seen any pictures of the process, so I thought I'd post a mini article.
All Spitfires bar the 1500 use a Delco Remy mechanical contact breaker distributor, which isn't the most wonderful pieces of equipment. The 1500's used a Lucas contact breaker system, and the American 1500's an electronic version of the same distributor.
The kit I fit today is an Aldon/Pertronix Ignitor 1149C suitable for all of the Spitfire's Delco Remy distributors, and probably a few other 4 cylinder Triumphs as well. Those running with a positive ground would need to be converted to negative beforehand, but I imagine those that would consider installing electronic ignition would be quite happy to do this anyway if they hadn't already. Surely the concours guys and girls get bored without a decent radio? There's plenty of different kits available, but the Ignitor fits entirely within the distributor cap, making for a very tidy installation. Externally, there's only one wire extra giving away your electronic ignition.
Edit: If you're wondering why the last two posts appeared at once I managed to leave the backend outputting to a test file, got distracted and never realised... oops!
I ordered the Ignitor from Retro Rockets in the States. It came to a total of £49.38, including delivery, which was in fact from their warehouse in England within 2 days. Aldon and Pertronix (originally Per-lux) are the same, so whether you order an Aldon kit over here, or a Pertronix kit from the States, you're getting an identical product.
You may wonder then, why I ordered from Retro Rockets... if I were to order from one of the Triumph specialists over here, or even directly from Aldon, the kit would set me back over £95 with postage included... to me that seems rather silly - it's as if they forgot to change the currency symbol!
Anyway, on to the kit itself - you get two fairly clear instruction sheets, even though its such a straightforward procedure. There's the control unit itself, attached to a semi circular plate for mounting within the distributor cap, a supplied screw for attaching to the distributor face plate, a magnetic collar and spacer ring for attaching to the distributor shaft, and two crimp connectors for the wiring.
Here we have the inside of the distributor before we get underway. The contact set (points) and capacitor (condenser) are fairly recent, but I'll not have to change or adjust them again, which is always handy. I plan to keep this set in the toolbox in case of emergencies, but hopefully I won't ever need to use them.
Both will need to come out - there's one screw on each, a wire between them, and a wire from the points to the negative side of the coil. Believe it or not, I did make a brief pass at cleaning the distributor face plate, but I guess the winter weather got the better of my elbow grease.
The Ignitor module screws in through the same mounting hole, with the pin for the points holding it in place. You may need to adjust the points adjusting screw to fit into the hole in the Ignitor plate. As you can see, it's a nice tidily made part which fits very easily.
The magnetic collar and spacer fit over the distributor shaft, with the rotor arm above. When I first saw the pair of wires, I didn't think they would reach to the coil, which alarmed me a little, but they did so with plenty to spare. You need to leave a little loose wire in the distributor so it doesn't rub on anything.
With the connectors crimped/soldered on, you attach one to the negative side of the coil, the other to the positive. As standard, the MkIV's have a ballast resistor in line to the coil, so as to give 12v to ease starting, and then drop down to 6v when running. If you are installing onto a car with a ballast resistor, you need to connect the positive side of the Ignitor to an ignition switched 12v feed. If the resistor is mounted on the top bulkhead, you can splice the Ignitor connection into the +12v feed coming from the fusebox, or fit a 12v coil, and simply disconnect the 12v feed, attach it to the positive side of the coil, and disconnect the starter solenoid to resistor connection. If the resistor is installed in the wiring loom, it's a little more complicated, but you should be able to find a white (ignition switched battery feed) +12v wire to connect to the Ignitor module, or to connect directly to a 12v coil. I had already completely removed my ballast resistor and fitted a 12v coil, so this wasn't an issue.
So, with everything installed, it's time for a test fire. Fortunately everything fired up first time - if you have any problems that could be related to the igntion, check and double check all of the associated connections. It's easy to dislodge a connection, or forget to reattach a battery terminal. If you're really stumped, it's straightforward enough to revert to the original points and condenser to test if the unit is faulty.
With everything running, you may find you need to readjust your timing/mixture/idle speeds etc. My timing was still fine, but with much smoother idling, I could turn the idle speeds down a little. So what about the results? Well as mentioned, my idling seemed a lot smoother, and it does seem much happier getting through the rev range, I guess the constant/higher quality of spark is responsible for these, though in my eyes it's worth the money for the reliability and time/effort saved alone. As you can probably gauge from the article, this installation is amazingly simple - why not give it a go?
Posted at 13:48
