Differences in Electronic Ignition

[Rally Pack 2000]

I have had electronic ignition on my Pinto Escort for over 25 years. Its the type that has a separate box module on the inner guard. (Cranecam X700 type). Always worked great although I think the coil has just packed it in this week which came with the Ingition kit. (27 years life for one coil cant complain about it giving up finally, they dont make them like that any more, they have even had a name change since then as it was an Allison Coil). Looking into systems again for my Twincam and notice that each of the companies offer the same module type but also what they call an optical trigger type. But the Module box type has an optical trigger too so Im a bit confused what the difference is in operation? The simpler optical trigger type is a points replacement and seems to be self contained within the distributor so it will look more original.

 

Im sure the answer is obvious but its totally alluding me what the differences are? Thanks

[Rally Pack 2000]

Just so people know what Im referring too Ive attached a PDF from Crane Cams that seem to show three different Ignition types. Which makes it even more confusing!

 

CraneIgnitions.pdf

[katana]

I only see two types as I would expect! The optical types either have vanes to break a light beam or a full disc with slots that generally block the light till a slot appears. The other is fully electronic that will have a steel toothed wheel passing a magnetic sensor (known as inductive pick-up) or a Hall sensor. The Hall sensor systems are probably the most efficient and give the strongest on/off signal and capable of such fast switching that when used on EFI systems can accurately read a 36 tooth wheel at 20,000rpm!

[Rally Pack 2000]

Thanks for that. So the XR-i one is the Hall type you mention then?

 

If thats the better type why is their top of the line one the XR700 an optical type? Whats the difference between the optical trigger type with the external box like the XR700 and the simpler optical trigger type at the top of the page? Sorry Im still a bit confused.

[katana]

Probably manufacturer 'blurb'! They will all probably perform admirably when new and the 'non contact' solid state ones similarly a 100K miles later but anything optical can be affected by dirt / dust etc. - unlikely in a dizzy but not impossible!

The kit that picks up off the 'cam bump / lobe' that used to open the breakers, is more likely to be an inductive pick-up as the peaks will be less defined using a lobe rather than a tooth which the Hall effect prefers - it how countless millions of bike engines have been triggered since the 80's (but using better rotors) If I had to use this route ie. retain a dizzy, I'd look for a kit that used a sleeve to fit over the cam lobed rotor to give better 'electronic' peaks - a Luminition kit I had in the 80's was like that and worked flawlessly. Otherwise i'd go the no-diz route and loose the dizzy, add a toothed wheel to the crank 36-1 or 60-2, Hall Effect sensor, electronic amp and either coil pack or twin tower bike coils and run wasted spark for a precise and timing mappable system!

Pick-ups are easily identified by wire count - Optical will have 3 wires and have an optic somewhere (obviously), Hall Effect will also have 3 wires (power, ground  & signal) but inductive / magnetic will only have two as the pick up produces a millivolt AC output in a sine wave pattern so just needs an in & out back to its amplifier.