Reproduced in part from "The Flying W" - the newsletter of the Wolseley Car Club of Queensland.
As always, this article is for information only - use of this information is entirly the responsibility of the reader. The article should not be substituted for specific professional advice.
Electronic Ignition update for my Wolseley 1500
The Wolseley 1500 uses the standard BMC B Series engine. Althought mine is the 1620cc, the procedure applies equally to any version of the A and B Series BMC engines - and just about any other 4 stroke engine that uses a distributor, coil and points!
You would have to agree that the "old make and break" points system could do with a helping hand. Not only is the system marginal in performance, some replacement points are getting harder to find.
When it comes to buying a unit, any car magazine, Hot Rod mag, speed equipment catalogue – whatever – will have a range of electronic ignition modules ranging in price from the Dick Smith DIY Kit right through to the electronic magneto / electronic full replacement distributors for supercharged V8 drag cars. Basically from under $100 to well over $1000. The unit I chose is the Optospark 500N by Electroweld Engineering (03 9336 7164) at $150 plus $6 freight. Electroweld have been doing electronic ignition modules since about 1984 – the 500N being one of their latest offerings.
Before you do anything – read the installation notes – then read them a few more times. Be very sure you know how to assemble the sensor unit before pulling the distributor apart. If you are uncertain you can complete the task – either get some good help or don’t try it at all.
Installation, according to the supplied notes, is as simple as 1 2 3.
Step 1 is very simple – attach the control unit to the mudguard somewhere near the distributor and coil.
Step 2 on the other hand take more than a little time. I found it easier to remove the distributor from the motor to do the points replacement. The instructions tell you to draw a line on the distributor body in line with the centre of one HT leads on the cap. Because I was removing the distributor altogether, I set the engine to Number 1 TDC to make the reinstallation easy. This is just to give you a reference point when putting it all back together.
Remove the points and condenser assemblies. Save the points locking screw. Now fit the sensor mounting bracket using the previously saved points screw. Next, remove the rotor button and fit the chopper disk to the shaft. Now test assemble the sensor to the vertical post of the mounting bracket making sure the sensor clears the chopper disk and sits at about right angles to the centre of the distributor shaft. Test fit the rotor button. If all looks like it will fit, go ahead and do the final assembly. If, as in my case, things are a little close, small amounts can be trimmed from the button to get the required clearance. Electroweld can modify some buttons to provide the required clearance.
Once everything is lined up, tighten the lock screws and refit the distributor to the motor.
Step 3 is again very simple. Attach the wires to the control box. Green for earth back to the motor (not just to the mudguard panel), yellow and orange to the coil, and the three wires from the sensor.
The moment of truth.
With the motor at the fire point on the timing marks, rotate the distributor body so the centre of the sensor lines up with the notch in the chopper disk. This will be close enough to start the motor. Set up your timing light, then go back over all connections – double check everything. Now start the engine and adjust the timing according to the workshop manual. Remember the dwell angle is preset now so don’t worry about it. Do make sure the vacuum advance unit works correctly, doesn’t bind and doesn’t have a hole in it.
If everything went according to plan, your engine will now start easier and in about 30,000 miles you change the plugs. All that for $150 and a couple of hours work fitting it up.