MG Car Repair: Cooper S distributor, vacuum advance, advance mechanism

Question
The Cooper 'S' distributor has been regarded as the ultimate of distributors for tuning Mini's and MG's. It has no vacuum advance mechanism. How does such distributor work and what is the advantage of this type of distributor over the normal Lucas type?

Answer
Hi Yahaha. The Cooper S distributor has a very good advance curve for the A series engine.  The engine will feel more responsive, but the lack of vacuum advance will mean that fuel consumption is not very good.  On a racing engine, fuel consumption is less important than maximum power, so it depends what you are going to do with the car.  If you are going to race it, delete the vacuum advance.  If you are going to use it on the road, ask for a distributor to be built for you with a similar curve plus a vacuum advance module.  I recommend a UK company called Aldon Automotive who will build a distributor to your precise requirements.