I've been meaning to change to electronic ignition for ages. I was hoping to go straight to Megajolt but with the RBRR coming up fast I decided it was time to get something sorted! I've heard good things about the kits sold by 'SimonBBC' so I got one of eBay. BBC stands for 'Best British Classics' in case you're wondering and they have a website (http://www.simonbbc.com) as well as selling on eBay.
The kit contains a red module to put in the distributor, special rotor arm, a magnetic 'collar', grease, cable tie and various other bits. The fitting goes a little like this...
Firstly, you need to whip off the distributor cap to expose its innards. You no longer need the condenser or the points so they can both be removed by removing the two screws. You need to reuse the screws so keep them safe! There is also a braid connecting the baseplate to the distributor body. It doesn't say anything in the instructions about it but I removed it and it worked so I guess it either needs to be removed or makes no difference!
Once you've stripped the guts out you can install the ignition module. This needs to have the base coated in silicon grease before fitting. I think the reasoning behind this is to dissipate heat into the baseplate and prevent overheating. The module has a circle cut out of the bottom that matches up with a lump on the baseplate so the module 'locates' very easily. The instructions tell you to put the screws in loosely so you can adjust the proximity of the module to the collar on the distributor shaft. I actually found that with the locating bump and the two screws there wasn't really any potential for moving it and just did up the screws.
Now you need to fit the rotor arm and collar. The kit gives you a couple of different ways of doing this. Firstly, you can use the supplied rotor arm which comes with a collar built into the bottom to activate the ignition module or, secondly, you can fit a separate collar and use your own rotor arm. I'd just bought a new top quality 'red' rotor arm so I went with the latter option.
Then all you need to do it pass the wires out through the distributor body and connect the red one to the plus side of the coil and the black one to the negative. It's really important to leave enough free cable inside the distributor to allow the plate to advance and retard. I checked mine by sucking on the vacuum pipe! The cables in the kit were a little strange. One was too long and the other too short! I sorted this with a little spare cable and a few crimp connectors.
I then threw it all back together and reconnected the battery. It was time for a test drive! I turned the key and the engine span over but nothing happened. Something was wrong and it wouldn't fire. I suspected my connections at first but everything seemed to be in order when I tested them with my multimeter. There isn't much in this kit that can actually go wrong so my suspicions turned towards the stuff in the diff! I fitted the rotor arm with the built in collar just to see if that made any difference and it did! The engine fired up straight away. Comparing the position of the collar on the rotor arm with it built in and where I had it with my normal rotor arm revealed the problem. Basically, I'd just pushed the collar too far down the shaft for its motion to be picked up by the ignition module. All I did was refit the normal rotor arm and pull the collar up to the bottom of it. Job done!
I haven't driven the car since doing it but just at idle it sounds much smoother and I'm sure it's going to make a huge difference to how the engine feels. I'm really glad I did it and I can't believe I didn't do it sooner!