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Ignition Module

  • Thread starter Thread starter genejohnson
  • Start date Start date
G

genejohnson

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Has anyone ever heard of using GM HEI Ignition Modules to replace those in our bikes? I just ran across something that I downloaded at some time and forgot about. It uses two of the GM modules to replace the stock module. My computer skills are nil so i haven't taken time to learn how to add attachments yet but I will e-mail them to someone if they promise to put it on the Forum. Gene
 
Yes, I have seen it done by another forum member. It seemed to work well enough, but there were other problems with the bike, so it did not get used much.

You want to send them to me, I'll post it for you.

.
 
OK, here are the pictures that Gene wanted posted:

GPZheiMod.gif


HEImodForPoints.gif


.
 
What bike? You do have a bike, right?
What about advance? HEI, relies on a mechanical spark advance?
I can see rigging up something to with a car module (and /or pick-up coil)to replace points type ignition.
but, with electronic ignition, if the ign timing is part of the oem module, how can you deal with advancing the spark with rpm?
 
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I wasn't trying to convince anyone of its use! Only wondered if the forum was aware of it. To consider it, researching the author's write up (if it can be found) and methods he used would be in order. AND YES I have a 1980 GS850 thank you. Gene
 
derwood said:
What bike? You do have a bike, right?
What about advance? HEI, relies on a mechanical spark advance?
I can see rigging up something to with a car module (and /or pick-up coil)to replace points type ignition.
but, with electronic ignition, if the ign timing is part of the oem module, how can you deal with advancing the spark with rpm?
Click to expand...

Only some of the late model GS's have the advance curve built into the ignition module. There are many others that use a mechanical advance - so the HEI conversion could be used.
 
Thanks nessism for the reply. Just out of curiosity I have looked in the 1980 GS850 manual and it doesn't say it is mechanical or done in the module. The book tells you how to time the 79 which is points driven but doesn't mention timing on the 80. If timing is done in the module, wonder if the mechanical advance mechanism from a 79 could be adapted to work with the module. (interfere with the module timing?) I have no intention of doing any of this but curious. For some reason, I'm always thinking outside the box. Gene
 
genejohnson said:
Thanks nessism for the reply. Just out of curiosity I have looked in the 1980 GS850 manual and it doesn't say it is mechanical or done in the module. The book tells you how to time the 79 which is points driven but doesn't mention timing on the 80. If timing is done in the module, wonder if the mechanical advance mechanism from a 79 could be adapted to work with the module. (interfere with the module timing?) I have no intention of doing any of this but curious. For some reason, I'm always thinking outside the box. Gene
Click to expand...

Gene,

If you go to Alpha-Sports or one of the other on-line parts fishes you can look up what parts the bike has and you can compare between different models to see what interchanges by comparing part numbers (you need to check all the numbers within each supercession chain).

To answer your question, the 80-81 850 have an ignitor with mechanical advance. Some people have fixed their 82+ bikes by retrofitting an early mechanical advance along with a Dyna S unit.
 
Thanks again nessism, I really appreciate your insight and knowledge. Gene
 
Matchless has a proper wiring diagram for using HEI modules with GS series bikes. I recently built my own ignitor using his design, and am just waiting for my new dyna coils to install it. With his permission I will post the schematic and a picture of my unit, and I will let you all know how the system works out on my bike.
 
Thanks matchless, I see there is a few changes from the schematic that I have for the Kawasaki 550. Did you ever have any success with it? If it proves to be worthy it could save folks some coins if their module goes kaput. I also ran across an article about using The Ford Duraspark module in the same manner (although its a bit larger). With the prices the Japanese charge for replacement parts, suitable substitutes would be worthwhile. I don't know the cost but I have heard that there are auto coils of the correct impedence (dual output types) that can also be utilized. I would guess that a lot of things that could be switched. Gene
 
genejohnson said:
Thanks matchless, I see there is a few changes from the schematic that I have for the Kawasaki 550. Did you ever have any success with it? If it proves to be worthy it could save folks some coins if their module goes kaput. I also ran across an article about using The Ford Duraspark module in the same manner (although its a bit larger). With the prices the Japanese charge for replacement parts, suitable substitutes would be worthwhile. I don't know the cost but I have heard that there are auto coils of the correct impedence (dual output types) that can also be utilized. I would guess that a lot of things that could be switched. Gene
Click to expand...

Gene,
Although I am not using it as my OEM one is in working condition, I have one built and have driven around with it and also loaned it to a mate who used it for a while. The changes were to lift the bias voltage a bit and bring the input pulse voltage closer to what the HEI units require. This is possibly due to the pickup coils configuration with both in series and no center tap.
Yes the coils apparently can be used, but we do not get them over here. On the GS there is hardly enough space for the OEM coils and I think any odd shaped coil will be hard to mount.
I would suggest that as first option rather try and repair the OEM one as the size and mounting is easier. I have a writeup on that in the link given earlier.
BMW 316i brake caliper piston seals and Fiat Uno rings come to mind as well!
keep well.
 
I run one of those HEI modules on my Ford Falcon using a Duraspark Dizzy to trigger it. Works great but those modules run HOT HOT HOT.

Make sure you have a decent heatsink, I tried one that was like a dual PC processor one - no use. In the end I have something much bigger on there! (about 4 time the size of the module in Aluminium, about 6mm thick & with fins & it still gets hot!)

They are cheap though, $17 a pop without even trying. I suspect you could get them at Rock Auto for about $12. They are quite high current (up to 8 amps depending on model) so make sure you use good size wires.

You could use any coil - the HEI Modules are not that fussy about what coil they use. I use an "E core" coil but it's not a twinspark one. The Ford Escort/Mondeo in the UK used to have a wasted spark setup that the coils would work from (Early Zetec engine, around 1990 ish).

Dan :)
 
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salty_monk said:
I run one of those HEI modules on my Ford Falcon using a Duraspark Dizzy to trigger it. Works great but those modules run HOT HOT HOT.

Make sure you have a decent heatsink, I tried one that was like a dual PC processor one - no use. In the end I have something much bigger on there! (about 4 time the size of the module in Aluminium, about 6mm thick & with fins & it still gets hot!)

They are cheap though, $17 a pop without even trying. I suspect you could get them at Rock Auto for about $12. They are quite high current (up to 8 amps depending on model) so make sure you use good size wires.

You could use any coil - the HEI Modules are not that fussy about what coil they use. I use an "E core" coil but it's not a twinspark one. The Ford Escort/Mondeo in the UK used to have a wasted spark setup that the coils would work from (Early Zetec engine, around 1990 ish).

Dan :)
Click to expand...

Very interesting info! Yes they can run quite hot, but this heat is reduced a bit if you use higher impedance primary winding coils or have ballast resistors fitted. At 12V with 4 ohm primaries you would draw about 3 A and with 2.0 ohm primaries you are up to 6 A. The closer you get to 8 A the hotter the HEI will get.

As you suggested a good (large) heatsink is important and so is using the heat conducting paste that comes with the HEI and having a smooth full contact with the heatsink.

This is unfortunately the main drawback I came across, the practical mounting of two of these in the limited space on the GS and keeping it vibration safe, sealed to the elements and cool can cause it to become a bit of a monstrosity.

Thanks for adding that issue as I did not really point that out. :)
 
Yes, my E core coil is an MSD hot spark jobby so must be low impedance. I think it only runs about 1.5 ohm's, prob explains the heat.

I would think the most practical place to mount them is on the back of the battery box.

Dan :)
 
salty_monk said:
Yes, my E core coil is an MSD hot spark jobby so must be low impedance. I think it only runs about 1.5 ohm's, prob explains the heat.

I would think the most practical place to mount them is on the back of the battery box.

Dan :)
Click to expand...

Sounds like you have an "arc welder"!!!

I am temporary wiring a KZ1300 1980 6 cylinder at the moment so we can test the motor. It uses very low impeadance coils, but has a ballast resistor for each coil. Primary 1.2 ohm and ballast 1.5 ohm = 2.7 Ohm and has a heavy heatsinked Ignitor.

I have installed the two HEI's inside two pieces of alluminium u-bar, then just flipped the two open ends together to form a box and they seem ok for the GS heatwise.
The OEM ignitor is only rated for 4 Amps and has a tiny heatsink on the two output darlingtons.

Keep well.
 
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