triggering an HEI module

[Bruce Plecan]

I already tired this with a Mallory Optical system
The optics were wayyyyyyyyy to slow to read the "synch" signals.
Bruce




> Hi,
> Has anyone tried to determine what type of signals will trigger an HEI
module?
> To be more specific with what I want to achieve:
> I have a little foreign four banger with a really pitiful points ignition.
I
> was thinking of converting it to GM DIS as a first step towards full-blown
> GM-EFI.
> The problem is that the only after-market conversions from points
available
> for this car are to 'optical sensor' ignition, which will result in a
square
> wave signal from 0v to 12v.  I know HEI modules (and DIS) are looking for
a
> sine wave.
> Does anyone know if a square wave will trigger the module?
> Even MORE specific:
> my idea is this: Crane makes a unit (the XR-700) that is optical.  Their
> generic kit comes with a bunch of 'shutter wheels, including one for a
v12.
> That's 12 slots.  Add two slots in the appropriate places (with an
> exacto-knife), and you have the correct pattern to fire a DIS unit (4cyl
or
> 6cyl... they require the same timing sequence.) (the GM DIS needs 6
equally
> spaced trigger signals, plus one 10' after TDC, per crank rev.) (you would
> double that if you were to plane on running it off of the distributor, as
I
> am.)  And for the time being, I would just keep the mechanical distributor
> advance, which would send that advanced signal to the DIS unit, thus
keeping
> my stock timing.  Pretty neat, huh?
> which leads to my second question.....
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