GM HEI Module - odds and ends

[Zed Head]

Assuming the same settings and drill speed, maybe the modified reluctor gives a higher voltage at low RPM. Four divisions for the Z, five and a half for the ZX. Can't tell what the settings are on your scope. Thanks for doing that and posting the results. No clear answer though on why the guy from Hybridz had problems with the HEI module on a ZX distributor. Maybe he had a bad module or had it wired backward.

I found a four pin Bosch module that apparently passes 7 amps. But you can get that with an Accel high performance module.

Also found that many of the Toyota people are using the GM module when theirs break, 'cause it's cheaper and works just as well.

[Captain Obvious]

The ZX pics are 2 volts/div vertical and 5 ms/div horizontal.

That means the ZX output is about 12v p-p with a period of about 15 ms. If I'm doing the math right, that's about 1300 RPM engine speed, so you're seeing an output just a little above idle?

For the Z pic I didn't record any of the scales, but I used the same drill and I wanted to get enough cycles on the screen to get a full conveyance of what the output really looked like. Also, it's not a storage scope, so I cranked the intensity up and between that and the little persistence natural in the phosphor I was able to get the shots. In other words, a faster horizontal access is easier for me to get a good pic, and I probably had the drill nearly full bore in both shots.

The point is... The horizontal axis is probably the same between both versions, but I really can't be sure about the vertical scale. Looking at the design however, I would expect the ZX pickup to give a higher output at the same RPM, and I also expect it to be more accurate because manufacturing tolerances between teeth would average out and there should be less jitter between cylinders.