GM HEI Ignition Conversion

[dhayes5]

I am getting the parts together to do the GM HEI electronic ignition conversion to my '72 240. I bought a '75 280Z distributor but turns out it was from an automatic and has two reluctor pickups. Apparently the second pickup is to retard the timing on if a temperature switch (on the 280Z) is closed. I disassembled this thing, cleaned and lubricated it and put it back together with only one pickup. I hooked it to an oscilloscope and the signal appears the same as before dissassembly. Any reason why I just can't remove this extra pickup? Also, there is a part called out as a "contactor" that I put back in but am unsure of how to set the gap. The contactor seems to come into contact with the shaft under the reluctor -- am unsure of it's function since it is electrically isolated from the rest of the circuitry - unless it is to ground the shaft during spark discharge. Anyone know anything about how to set the contactor gap? Finally, with respect to the GM HEI module. I read that it is reliable and that it is prone to overheating. Does anyone have any experience with this and or another ignition module that they have had success with?

Any help would be greatly appreciated.

[Kyle]

Hi there-

<p>

If you're sure of which pickup to use (they're probably oriented differently with respect to the distributor cap) you can safely remove the extra set. Or! Get creative and hook up a knock sensor..... theoretically, you could have it automatically retard the timing when it starts to knock/ping. May or may not work, but I've been waiting for someone to give this a shot;-)

<p>

I don't know about the 'contactor', sorry... that's a new one to me.

<p>

I got an El Cheapo module from Kragen three or more years ago and have had ZERO problems with it. It might be prone to overheating in a big ole nasty V8; especially since they live inside the distributor. The GM HEI swap locates the module well away from the engine, on an aluminum plate that functions as a heat sink.

<p>

HTH

<p>

Kyle<br>

http://www.sonic.net/~kyle/ztech.html

[Jetaway]

<p>DELETED<p>

I got an El Cheapo module from Kragen three or more years ago and have had ZERO problems with it. It might be prone to overheating in a big ole nasty V8; especially since they live inside the distributor. The GM HEI swap locates the module well away from the engine, on an aluminum plate that functions as a heat sink.

<p>

HTH

<p>

Kyle<br>

http://www.sonic.net/~kyle/ztech.html

There seems to be several different GM HEI modules, as well as several 280Z distributors that can be used in a 240Z, so your set up may be significantly different than mine, but ...

I mounted the GM HEI (actually an $18.00 bottom barrel aftermarket) on an aluminum plate which was cut to fill (and a little more) the gap in the side of the distributor formerly occupied by the E12-80 ignitor. It gets hot here and in the year, more or less, since I installed it, no problems.

The HEI looks like the first one on this page.

http://www.performancedistributors.com/modules.htm

I don't have this particular brand, but suspect I will be getting one, or something similar before summer is out. Not because I expect the installed ignitor to die, but just, well, because.

Chris