TECHNICAL TIPS - IGNITION

CENTRIFUGAL WEIGHT SPRINGS Forming your own centrifugal weight springs can be achieved from a readily available open 3/16” spring.  Slide it on to a 3/32” drill or similar (nail?), gently heat with a blow torch until a dull red, squeeze up the spring until closed and sparingly spray with water to cool i.e. - not too quickly. Cut to a suitable length, make off the ends and fit. It does take a bit of patience, but it works!

COIL CONNECTIONS:To get the right flow of electricity to plugs, make sure the following connections to the coil are the correct way round:  Negative Earth cars:  the negative tab on the coil (-) goes to the distributor/contact breaker.  The positive tab (+) goes to the battery (+) via the ignition switch.  Positive Earth cars:  the positive tab on the coil (+) goes to the distributor/contact breaker.  The negative tab (-) goes to the battery (-) via the ignition switch.  On older coils with SW and CB marks, rather than + or -, one cannot tell what car they were originally designed for and so the following flow test can be performed with a sharp, soft pencil (if you are brave enough and not fitted with a pace-maker!):  With the engine running, disconnect a plug lead from the top its plug and hold the end of the lead about 1 cm away from the top of the plug so that it makes as long a spark across the gap as possible.  Introduce the tip of the pencil into the electrical stream.  The ‘lead’ of the pencil will be seen disintegrating and blowing away in the direction of the electrical stream which should be towards the plug top.  However, it is probably safer to go out and buy a modern coil!

CLEANING THE DISTRTIBUTOR CAP: A small flat rotary wire brush that just fits inside the distributor cap will clean all four contacts and the carbon brush in a trice.
RE-TIMING: If you need to take off your dynamo to change the brushes and do not want the hassle of re-timing afterwards then this can be achieved quite simply.  Put the car in neutral and remove the distributor cap and rotor arm.  Turn the engine over with the starting handle until the notch on the central spindle of the distributor (that the rotor arm locates on) aligns with the foot of the contact breaker.  From this point onwards ensure the engine is not turned or moved.  Remove the dynamo and replace the brushes.  When refitting make sure that the notch and contact breaker foot once more realign.  If not slide off the dynamo and turn it slightly before refitting and repeat until alignment occurs.  This is easier that it might sound because one tooth rotation on the dynamo means a significant misalignment at the notch/contact breaker.  Don’t forget to replace the rotor arm!  Peter Trebilco
NEW CONTACT BREAKERS: The replacement Contact Breaker sets available for the DJ4 and similar distributors have the contact hidden within a 'C' shaped lever. To set the gap at 12 thou with normal feeler gauges I have found difficult! It has also been difficult to see exactly when the contacts are opening as I check the timing. Then a clever man via Oz (Steve Jones of the PWA7C) said:-1) "Why don't you use the original Lucas contacts" or 2) "Why don't you grind away the legs by the contact on the lever". To my knowledge there are not many un-used original Lucas Contact sets about, so I decided to try the second option, but only doing the top leg, converting it from a 'C' shape to a 'L' shape, on the basis that some strength is retained with the bottom leg and I can see the contacts clearly with just the top leg removed anyway. I also painted the bottom leg under the contact white to making sighting the contacts easier - Problem solved, it's too easy for words. Sandy Croall Cornwall Austin Seven Club
CONTACT BREAKER HEEL: The old Box was definitely getting breathless with no power and the occasional cough or choking fit. In the true spirit found elsewhere in these columns, I tried everything until hitting on the following:  The contact breaker heel was almost worn away! David Whetton
ELECTRONIC IGNITION: I recently converted both my Austin 7s to contactless, or electronic ignition.  Both my Austins are 12 volt with Boch distributors as supplied by Willie MacKenzie, however I am given to understand that a 6 volt version is available.   It is very easy to fit, just remove the points and condenser from your Boch distributor and screw in the base plate of the ignitor in its place, push the circular magnet sleeve onto the distributor shaft, making sure it goes right down to the lip (it's a tight fit) refit the rotor.  Connect to red wire to the positive side of the coil and the black wire to the negative side of the coil (negative earth)  Job done.   I do feel however that the 'Ignitor' and the  appropriate Flamethrower coil should be bought together.   The manufacturer is Pertronix look at www.pertronix.com.   The total cost of the Ignitor and the Flamethrower Coil was about £120 .   Definitely gives improved performance and smoother running.   I purchased it through Coolair.com Glyn Llewellyn
POOR PLUG LEADS: Poor insulation on your plug leads: It is normal for this insulation to deteriorate over time as it was originally made of rubber, which is a natural biodegradable material; this is why you occasionally get an electric shock when touching the leads when the engine is running. To check, run the engine in total darkness with the bonnet open and look for a blue hue on the outside of the plug leads – this shows that some of the electricity is taking the easier path to earth down the outside of the lead rather than having to jump the 25 thou gap from the central conductor of the sparking plug to the earth prong. Modern cable is made with neoprene sheathing which does not deteriorate. However, it does come with two kinds of central conductor. Ensure that you buy the version with a real copper centre conductor otherwise you will have trouble fitting the original terminals on either end. The other type has a graphite based core to automatically provide ignition suppression for car wireless reception. Yours Bumbling (A7OC) With many thanks
SPARK TESTER: Take an old spark plug and weld onto it a large crocodile clip. Carry this with your other spares and it will enable you to test for a spark without the need to remove any of the plugs — just clip it onto a lead stud and connect a lead.     David Whetton, Dorset A7C
TIMING: The starter ring gear has 80 teeth so each one is 4.5 deg. Very useful for correctly setting the ignition timing. Vince Leek