From: noel shelley (noel@shelley1722.freeserve.co.uk)
Date: Tue Nov 16 2004 - 04:14:17 PST
Hi Jack ,Bjorn and the list ,
The following applies to any multi cylinder
gas engine !
When timing the ignition one sets it on No 1 cylinder . What is not commonly
known is that the accuracy of the lobes of the distributor cam is at best
poor and therefore the timing of the other cylinders maybe several degrees
out , both ahead and behind ! Indeed on inspection in a random selection of
25 cams none was found to be better than 4 degrees lobe to lobe .
Whilst one can get a bigger fatter spark by an electronic system triggered
by the points , the above is still true and even a magnetic trigger will
only partially solve the problem . There IS one system that addresses the
accuracy issue and bigger spark as well , LUMINITION , this is an optically
triggered system that uses an infra red beam broken by a rotating segmented
disc pushed on to the rotor shaft below the rotor and a Magic Eye that fits
where the points were . The accuracy of the disc is such that the cylinder
to cylinder timing is 1/4 of a degree .
Using the original distributor and coil , apart from the three small
coloured wires from the distributor and hiding the electronic block , it all
looks standard .
Though no kits are made specifically for the MV engines , it is possible to
adapt the components to fit most distributors , be it 4-6-8 pot , even to
the extent that it is possible to fabricate a chopper arm if the normal one
won`t fit .
First made over 30 years ago , they are still available , though not cheap
at £120 . I used one on a bad tempered engine , that was hard to start and
idled badly , the difference was remarkable . The power of the spark was
such that you didn`t gap the plugs , just brake off the side electrode , on
a damp night the HT ignition just glowed and woe Betide you if you put your
fingers near it !
The varying operating conditions made a before and after comparison of fuel
economy and performance difficult , though it performed some interesting
feats !
With the damp mornings of winter upon us this may be of interest to some .
Best wishes all Noel
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