Subject: Re: Magneto v distributor
Hi David,
Coincidentally my LG6 has exactly the same set up. When I bought the car, the magneto worked, but the distributor side packed up fairly quickly as the rotor arm burnt through. It was a new one made by "Park". There was a spare "Park" one with the car so I fitted that, and that lasted about two weeks. I then fitted a very well used Lucas rotor arm...end of trouble. So watch what parts you buy!
Not long after I enjoyed distributor reliability, the Vertex magneto packed up (despite having been rebuilt by D H Day not many miles previously). I've yet to resolve the problem, but it is useful for switching on whilst driving through tunnels to enjoy the backfires. Anyway...had no problems with the distributor or its wiring overheating, and like yours, it feeds the exhaust side.
I have a stainless exhaust manifold, but I would imagine that would perhaps radiate more heat than the original cast iron version. I doubt unburnt fuel is your problem; whilst there is doubtless some, it will be no more than that not fired by a normal single ignition engine. More likely, I would think, is that your ignition timing is out, or bearing in mind care might not have been exercised in choosing that distributor, that the centrifugal advance curve is unsuitable.
At least with a twin ignition system, you have two bites at the reliability cherry!
Laurence