[Mgs] 123 ignition

[Paul Hunt]

The original mechanical curves are no different to the 123 MGB curves i.e. 
they are both irrelevant with today's fuels.  The difference is the 123 is a 
lot more expensive than a decent mechanical rebuild - what I can get in the 
UK at any rate.  The advantage of mechanical over 123 is that with the 
mechanical if you really wanted to you could tune the curve to match your 
engine and fuel.  With the 123 you are limited to going through 16 arbitrary 
(if you use the non-MGB version) curves to determine which is best for you. 
Whilst some are bound to be better than others one is unlikely to end up 
with an ideal one.  My caution with any electronics, be it the full 123 or 
just an electronic trigger, is that when they fail they usually do so 
totally and without warning, and you have no option but to substitute.  With 
points they usually drift rather than fail, are pence to carry around as a 
spare, and can be swapped easily at the roadside.  Many moan about problems 
with points, but I've been using them for 40 years and never had a failure 
of them or a condenser.  I am planning to change both my roadster and V8 
points this year, after many years and some 15k miles each.  I've not had to 
touch the roadster points in all that time, and the V8 have only needed one 
small tweak to get the dwell back into the window, as they only have plus or 
minus one degree tolerance whereas the roadster is plus or minus five 
degrees.  I realise I am unlikely to convert anyone who has gone electronic 
of any type.  But those contemplating going electronic could do well to 
consider that whilst replacing a knackered mechanical item with a new 
electronic *is* likely to make a noticeable difference, so would replacing 
it with a sound mechanical unit, and usually at a fraction of the cost.

My 2 penn'orth, and you did ask :o)
PaulH.

----- Original Message ----- 
>... Could you
> please explain why the set of curves delivered with the 123ignition is
> irrelevant with today's fuels and what makes your mechanical rebuilt
> distributor suitable for these fuels?
>
> Maybe I haven't got your point but what are the advantages of a mechanical
> distributor over the electronic type?