MG Car Repair: Electronic ignition vs points, electronic conversion, advance mechanism

Question
Hi Barrie
I am considering a move to electronic ignition for a 74 MGB but have heard that conversions are not a 100% improvement. Can you give your opnion - electronic vs. points ?

Answer
Hi Paul.  The original distributor fitted to your 1974 MGB worked perfectly well when it was new.  You must regularly check the points, keep them gapped and lubricate the advance mechanism, but so long as you did this the system would be OK.  However, after nearly 40 years it is probably well past its best, the spark timing will vary from one cylinder to the next, and both the mechanical and vacuum advance mechanisms will be worn.

You could fit an electronic conversion to your existing distributor.  Many companies sell these.  My 1955 MGTF has had a Pertronix unit inside it for the past 10 years and I am still very happy with it.  Starting is instantaneous and the engine runs noticeably more smoothly.

Assuming that you still have the original distributor in your MGB, I think it would be a mistake to fit an electronic ignition conversion to it.  With a worn distributor you will not obtain the maximum benefit.  I would therefore recommend that you fit a complete brand new electronic distributor.  These are now available at a modest price.

For example, see:

http://stores.ebay.co.uk/Simonbbc-Ignition-Solutions?_trksid=p4340.l2563

These units look identical to the original Lucas items, except that there are two wires coming out instead of one.  Thereafter, you can forget all about points and condensers.  Just remember that they do still have a mechanical advance mechanism and they do rotate, so they still need a drop of oil every 12,000 miles.

If your MGB has a modified engine, companies such as 1-2-3 sell a unit with a fully electronic advance curve built into it, and you can select from 16 different curves by turning a small switch inside.