Hi all, love this forum, this is my first post though. Let me say first I've searched on my question stacks and haven't found the info I'm after.

Have been doing much research and searching about the direct fire ignitions. My trouble at the mo is in Australia, 2nd hand ignitors are hard to come by (I'm sick of wreckers laughing at me down the phone) It seems that there can't be much in that little box. I'm wondering if anyone has reverse engineered an ignitor? Or, when you've stripped a blown ignitor, can anyone send me a pic of it's guts? Looks like they can be built from parts much cheaper, and I'd know what's gone wrong if it dies (again ignitors are rare here). Petrol over here varies, and I'm finding that I have to shift my timing to different types of petrol (have decided that Mobil 6000 is the best for me, 96 octane, but can't always get it,and the regular unleaded is crap.) So a DIY ignition kit may allow me to install a simpler timing adjustment in the dash. Also planning to mod my points dizzy to IR (infrared) pickup.

Cheers

 

I have emailed Mazda for info, but am still waiting (And am not too confident about the response I'll get)

 

I've read that some people have been using 70's GM HEI modules on them with good results and on some there was a pin to retard the timing by 10 degrees but I dunno how that would work on a rotary.

 

Thanks numan2. That's what I'm onto at the moment. Figure they are compatible, cause I've read them in writeup's, and there's bound to be more info on the GM part huh? Yeah, I'm resaeching that at the moment (in between earning my pay he he)

 

I'd stick with sourcing the GM HEI modules. They're cheap and easy to adapt to our ignitions. Also used J109 ignitors are available on Ebay from time to time, but buying something like an ignitor sight unseen is kinda sketchy.

 

Do a search on HEI here and you will find tons on the change over.

You could just get j109's from the states. I am sure some of us could sale you several.

 

Thanks MosesX605 and Hades12. I am thinking that's the only way to go,as far as OEM parts. You're right, I'm not keen on buying used ignitors over the web. I'm trying to find particular model numbers for the GM HEI's, as spare parts shops over here don't know which model I'm on about, and neither do I sort of. (Yet) A friend has given me a TFI (Thin Film Ignitor) from a Ford, which is the same thing, and apparently adapts to points or Hall effect pickup.

It occured to me last night, while googling, that the model #'s 'J109' and 'J105' could reflect that their based on the J109 and J105 JFET's. I looke at the specs for them, and they are 25V transistor's, designed for temps up to 150 degrees C (enough for engine bay temps) and have a max IC current of 350ma's, which sort of fits the basic principle of an ignitor. They may trigger an SCR or another fet in the ignitor casing. Once I found that, I was pretty sure that I could design my own ignition circuit, and even use GT40 coils and something to inhibit back EMF like a diode (apparently the GT40's produce some sort of back current which is OK for points but can screw a Hall effect sensor) And I'm also thinking that if I'm building it myself, I may aswell do the trailing aswell. Not much added gain from what I've read of Jeff20B's investiagtions, but at least that way I can remove the dizzy rotor all together and convert the dizzy to an IR pickup. Need to take a digital pic of the dizzy, print at actual size and do some measurements.

Still haven't finished investigating this, but it makes more sense as I go. I was concerned about how to limit the current to the coils, but I figure that the resistance of the primary coil will actually limit the current thru the FET's itself.

If it works I'll dyno it and put up a schematic to try. Or give it a go and let me know. I'm going to install the TFI this weekend on the leading side, so won't attempt my own until after seeing the results of that. But I have an autox day in March, so it's got to be working by then.

On a different point, anyone thinking of welding their dizzy (which isn't easily reversible, and you have install the dizzy one notch back), try removing the springs and wiring the weights in. I'm going to try this soon with some stripped twist ties. Less spinning weight in the dizzy, reversible and probably takes 5 mins (plus resetting ur timing a bit) not sure what this does, but I guess it gives you more torque????