HEI Conversion question

Thank you for testing that and checking it out! I will adjust the wiring tomorrow and see how it goes!

I just noticed something too from your original HEI diagram on your website. It says to connect the 1 and 4 lead going to the coil to the black wire, and the green wire to the 2 and 3 coil. In my clymers manual I have, it says 1 and 4 are green and 2 and 3 are black. Obviously this is an easy change for me to do and not a big deal, but I'm not sure if this has come up before. Unless the clymers is just wrong. (Could be, I don't treat it as absolute fact)

So just to make sure, I am going to take the red and blue pick up wires and go straight to their respective W terminal? I don't want to connect those to ground as well, just straight to W

freebyrd24 wrote: So just to make sure, I am going to take the red and blue pick up wires and go straight to their respective W terminal? I don't want to connect those to ground as well, just straight to W

Yes. That is my best guess based on the scope results.

Actually, the tests show connecting them to ground may work just as well, and 50/50 chance it may be slightly better that way. It's kind of a toss up. I will do more tests tomorrow if I get a chance. I was only able to do some minor preliminary tests today. But if it comes down to a toss up, I would err on using the manufacturer's intended connections first.

By the way, I'm really glad this thread came up. The implications of this new style module are that the dwell will now go over 180 degrees at higher RPMs. This is a good thing for anyone running 3-ohm coils (as I see you are). 3-ohm coils are a little slower than the factory 2.3-ohm coils, so they can benefit from the extra dwell at high RPMs. This means more reliable firing with motors running slightly bumped up compression or larger plug gaps.

I woke up this morning and the spark has disappeared! I've tested for power, continuity to ground, and everything that I could within my electrical ability, and I have no idea what happened. Just overnight spark disappeared. I tried hooking up the red and blue wires to the W terminal, and that didn't create spark either. Any thoughts?

UPDATE! So I tested spark on 1 and 4 and it was no good, but then I tested 2 and 3 and it had spark. So I thought that the module may be bad. Since I have a hefty reserve of these modules, I replaced the 1 and 4 module. I also to be safe, then hooked the red and blue pickup wire to the respective module on the W terminal, instead of straight to ground. That gave me spark again! I just tried to fire the motor and it started! I just ran it for a few seconds, but it started up. So I think the W terminal is the correct way to do it.

So i buttoned everything back up, went to fire, now 2 and 3 have no spark. I don't know if the modules are fighting each other? Or what's going on. I'm going to replace the 2 and 3 module with another module and see what happens.

When I get to work I'm going to hookup a full setup with a pickup signal simulator and coils etc. Then I'll be able to test for any other strange behavior the new module design might exhibit.

Things are not testing well on this new module. The module is trying to do too much "thinking". While testing with an actual coil, I've had the module lock up a couple times where it stopped sparking entirely. It is also giving multiple sparks when there should only be one under certain circumstances. It is also errantly increasing dwell far beyond what the input signal is calling for at inappropriate times. So there will be a lot of investigating required to get this working properly.

Not what you wanted to hear, I'm sure. But at least it confirms what you are experiencing.

It does seem the fastest way to get up and running would be to use the original design with a Wells or Duralast (from Autozone) DR100 module pair.

I'll do some further tests, but will have to do some actual job-related work at some point .

I'm actually having some big issues with idling, so this will stop me from chasing my tail with jetting. I'll seek out those other modules. So should I go back to original design that is on your website that includes diodes and resistors? And the combined red and blue?

freebyrd24 wrote: I'm actually having some big issues with idling, so this will stop me from chasing my tail with jetting. I'll seek out those other modules. So should I go back to original design that is on your website that includes diodes and resistors? And the combined red and blue?

Yes. This is assuming the design on the DR100's haven't changed as well.

With some more experimenting, I could get the module to work reliably using coils that are less than 3 ohms. 3 Ohms appears to be the limit. If I use 4-ohm coils I get erratic behavior. With 2.2-ohm coils it's pretty good. I used different voltages to see if that made a difference. I still have to try using an unregulated supply source to see if that messes things up.

For reference, I swapped in one of the old GM units from ebay. It works very predictably, and reliably with 2, 3, and 4 ohm coils, albeit at slightly different threshold levels. So the erratic behavior is definitely those BWD CBE4P modules.

Hi Lou,
I just wanted to give a quick update. When I swapped in the dr100 modules and used the wiring per your website, the bike ran better, but I have idle issues. I'm fairly confident it needs a carb sync, so I don't think my idle issue is all from the modules. I'll try to carb sync by this weekend and see if I am all set, but those modules from bwd might have been close to working properly