What is it - again!
 

Hi all,

I decided to lift the bonnet on my fourth 164 which is a 1969 manual. First time I’ve looked under here since getting it delivered a couple of months back!

I’ve found this wired in, it’s own ballast resistor, seems to have a coil HT take-off but the original coil and resistor are the ones actually connected to the distributor.

It’s clearly something to do with ignition - perhaps early electronic module of some sort? The label is worn but perhaps someone can recognise from the logo or shape and I can then research a bit more.

Thanks

It looks like a very early (contact assisted) electronic ignition unit. In the early 70s (and in fact later) many of the hobby electronics magazines of the time (Elektor, Practical Electronics, Everyday Electronics and similar) produced circuits for contact assisted electronic ignition units, some also had bespoke PCBs made and also bespoke heatsinks made - these were sold at cost + a small percentage to readers wishing to build their own that used what was already tried and tested and/or didn't have the facilities to make their own.

If you can figure out the connections that make it work then try it and if it still works, all good. If not, revert to standard and sympathetically remove it.

Another thought that crosses my mind is it could be an early cruise control servo - the "HT" connector could in fact be the Bowden cable entry point - unexpected extras on the throttle linkage will add evidence to this theory.

Its the dilithium crystal package from the Starship Enterprise warp drive module. Reality check - its a Judson Electronic Magneto which I recall was their version of a capacitor discharge ignition system combined with an integrated ignition coil. The two little men symbol was the give away. I am sad to report that I remember this from seeing the originals. What a waste of limited neural storage capacity!

https://mgaguru.com/mgtech/ignition/pdf/jud_mag.pdf

Capacitor discharge ignition was useful on 2 stroke engines because its very fast rise time was able to fire oil fouled spark plugs. It did have a very short spark duration which made it less effective at insuring a good fuel burn. For 2 stroke engines, being able to fire a crudded spark plug was the lesser of two evils trade off. Capacitor discharge ignition was never a good choice for a 4 stroke engine unless it was burning so much oil that it looked like an older Vespa motor scooter fogging the streets for mosquitoes.

The HV terminal of the integrated ignition coil was that tower sticking out of the device at the top of your photo. Since there is no HV cable from that terminal to your distributor, it is now obviously out of service. I suggest that you completely remove it and send it to a hazardous waste disposal specialist or donate it to the museum of bad ideas from the '60s.

Awesome information there! Glad my guess was sort of correct about it being an early electronic ignition unit but interesting to learn it was effectively a CD-i unit. :thumbs_up:

Thanks to all for coming back - fascinating to learn about this and it will be coming out in the next few days. Sadly it seems I won’t be earning millions from this defunct unit on eBay.....

......... you could always reverse engineer it and return it to working order then sell it in working condition as a museum piece. There are places on this planet that pay incredible amounts for such items that are restored to working condition but by their age, are only fit for museum use.