[PSIG]

One other idea for phase detection …

Do a search, and you will find dozens of creative ideas for cycle sensing. Rocker tip sensors, timing chain gears, lobe sensor, distributor shat grooves, pushrod sensing, pump cam sensor, MAP of one cylinder, etc. Usually Hall or other digital sensor, but there are no limitations. Creativity by simply looking at everything in the engine that rotates or actions at half-speed will get you there somehow that's easy, cheap or other benefit.

While not every idea is perfect, I recall someone printing a black/white trigger wheel on paper, gluing it to a disc and using an optical sensor in the distributor. It worked, and while only a test, shows options that are unconventional. This is the value of concepts, over instructions. Once you know what you need to achieve, you can do it 101 ways that the factories did not (or exactly that way).

[LPG2CV]

Another option to throw in the pot, is an optical sensor, and the wheel does not need to be ferrous.

[notarobot]

While not every idea is perfect, I recall someone printing a black/white trigger wheel on paper, gluing it to a disc and using an optical sensor in the distributor.

When I first got a Speeduino several years ago I built a basic test rig to evaluate Speedy and that used exactly this method . I remember
it not working at first because the laser printed segments were not dark enough - but once I coloured over them with a pemanent marker pen it ran perfectly - in fact would run scarily fast without glitching.

[apollard]

Here's a 50mm wheel setup for Nissan distributors using optical sensor. if you are making something to fit, worth a thought

https://www.diyautotune.com/product/50- ... or-ka24de/
https://www.diyautotune.com/product/54- ... -or-vg30e/

[LPG2CV]

i hadn't realised @psig had already posted regarding optical.

I had my brother in law, laser cut me a trigger wheel from phenolic board. Same stuff as pcb are made from. It stank so much, he wouldnt do it again. So I thought I may send away to a pcb manufacturer to get some made. the bare boards out of China, are really cheap, it's the global postage that puts the price up.

[PSIG]

Ah, now you're letting the cat out of the bag.

[notarobot]

Rather than modding the bottom part of distributor to mount a HE trigger I am wondering if the slot on distributor shaft which normally locates the rotor arm could be used as trigger for a Hall Effect gear tooth sensor? Shaft is approx 7.5mm diameter with slot as per photo.

With a 36-1 crank trigger to run full sequential I believe I just need a single pulse type signal from cam (distributor). Are there any particular advantages/disadvantages to using various shape/style triggers - e.g. half moon, 4-1 wheel, single arm wheel etc?

John

[PSIG]

I have used a slot (ground with a cutoff wheel) and another with a flat area ground into the shaft, almost 'half-moon'. There's a photo somewhere on here. "Tooth/slot" dimension will depend on what sensor you use. If the sensor has a wide aperture (viewing/sensing angle for larger teeth), a small wheel or modified (steel) rotor tip can be used. Get creative and have fun.