There are actually four generic distributors for 4-cylinder MGBs (25D4,
45D4, 45DE4, 45DM4), the two points types can be fitted to either positive
or negative ground cars, the two electronic types were only fitted to
negative ground. By playing around with the static timing the advance curve
remains the same as they are referenced in terms of *additional* advance, it
is just the starting point that varies.
The symptom for the points plate ground wire going intermittent is the
(electronic) tach flicking around in time with the cutting in and out.
----- Original Message -----
> there are 2 (generic) dizzys (4- and 6-cyl.) for British cars with Lucas
> distributors where the rotor turns ccw (top view). They fit cars with
> earth. You can choose from 16 curves and play around with the static
> which gives you an indefinite number x 16 curves.
> BTW: Had an interesting ignition problem recently. The wire that keeps the
> rotating Points/Pertronix plate grounded in the distributor became
> intermittent. (After only 150K miles, imagine that.) The engine would
> die, but
> always started right up again.