Just a few random thoughts on the subject.
The only advantage of a dual point distributor over an equal quality single
point distributor is the increased dwell time allowed by the dual points.
Keep in mind that the dwell time on a V8 with single points at 5000 rpm is
exactly the same as a four cylinder at 10,000 rpm. Most V8s in street use can
get by with a single point distributor quite well, so unless you often find
yourself runnibg in the 8,000 - 10,000 rpm range, the benefits of the dual
points will probably not be noticed.
Notice I compared dual points with single points of EQUAL quality. It may
very well be that the quality of the Mallory dual point unit is sufficiently
better to justify the cost, even if you don't need dual points.
Long before there were electronic ignition systems, these cars ran quite well
with the old point type distributors. There is no reason why they won't do so
now. However, the reduced maintainence required for an electronic system,
using photo-optic or magnetic triggering, is reason enough to go with
electronic systems. If you install a good system, and time it once, you may
very well never have to adjust it again.
Electronic systems are not affected by wear in the distributor as much as
conventional points. Timing and dwell can vary quite a bit with conventional
points, as the distributor shaft "slops" around in a well worn distributor.
The same distributor can deliver rock solid timing with the substitution of
elctronic sensors for the points. Of course, a new points type distributor
will do the same.
An electronic ignition system can fail catastrophically, leaving you stranded.
A conventional points system usually (but not always) goes out gradually, and
you can limp along til you get it fixed.
Whether you need a ballast resistor or not is determined by the coil in a
conventional points system, and by the coil/module combination in an
electronic system. Follow the manufacturer's advice. Some do and some don't.
Installing a ballast resistor, or removing one, is extremely easy to do.
Instructions for doing so should be provided with the igniton module. If not,
I will be happy to provide them for you. In the meantime, refer to the
article on Ballast resistors on the VTR web site for more information on this
subject.
Staring is often easier with an electronic ignition system, because of the
hotter spark supplied. The addition of a higher output coil to a conventional
system while also improve starting.
Hope this is of some help.
Dan Master,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/
'74 MGBGT---3000mile/year driver, original condition - slated for a V8 soon
'68 MGBGT---organ donor for the '74
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