Have you done a write up on this, because I KNOW there's some of us "want to know"
HEI in Mopar ECU casing
- Thread starter Pompis
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Have you done a write up on this, because I KNOW there's some of us "want to know"
Originally Posted by Jkirk
I went to the full GM TBI system, with computer controlled HEI, heated O2, Knock sensor, speed sensor, and electric cooling fan on a 65 2 barrel 273
I would kill,to see the wiring schematics.....
I went to the full GM TBI system, with computer controlled HEI, heated O2, Knock sensor, speed sensor, and electric cooling fan on a 65 2 barrel 273
I would kill,to see the wiring schematics.....
Using the GM HEI module outside of it's dizzy, just bolted to a fender liner or what-not, had always bugged me from a corrosion potential position. Here on the Coastal Desert I've got to consider such things. One could argue that the GM dizzy isn't a sealed container for the module and I'd agree, but it must be good enough elemental shielding because corrosion isn't a usual complaint.
I'm liking this mod because it provides about the same amount of shielding from the elements as a GM dizzy does, maybe more and it's cool because it's not what people who see it think it is. Years ago (~1988 ) I put a Toyota EI module in one of those old 70's era aftermarket CD Ignition housings and converted the dizzy to the Toyota inductive pick-up too. Looked like an old points driven CD ignition, but was something far better.
As to the TBI wiring, there are many, many wiring diagrams out there suitable for the conversion. The 7747 ECU is the most common and pretty much the only ECU used in swaps. A simple search on the topic will turn up more info than is useful. I have the complete system from a 2.8L GM V6 that I'm working towards installing on my 170ci (2.8L) slant. The biggest issue for me is that I don't want the ECU to have control of the timing at first. So how to send the RPM signal to the ECU w/o also allowing timing control or altering the loom is a dilemma that I've got to solve. Eventually the ECU will have timing control (doing one step at a time), so altering the loom isn't very desirable.
Attached is one such diagram that I found on an I-H site where TBI conversions appear to be quite common.
EDIT: Just now looking at the attached diagram I see the solution to my timing control situation.
I'm liking this mod because it provides about the same amount of shielding from the elements as a GM dizzy does, maybe more and it's cool because it's not what people who see it think it is. Years ago (~1988 ) I put a Toyota EI module in one of those old 70's era aftermarket CD Ignition housings and converted the dizzy to the Toyota inductive pick-up too. Looked like an old points driven CD ignition, but was something far better.
As to the TBI wiring, there are many, many wiring diagrams out there suitable for the conversion. The 7747 ECU is the most common and pretty much the only ECU used in swaps. A simple search on the topic will turn up more info than is useful. I have the complete system from a 2.8L GM V6 that I'm working towards installing on my 170ci (2.8L) slant. The biggest issue for me is that I don't want the ECU to have control of the timing at first. So how to send the RPM signal to the ECU w/o also allowing timing control or altering the loom is a dilemma that I've got to solve. Eventually the ECU will have timing control (doing one step at a time), so altering the loom isn't very desirable.
Attached is one such diagram that I found on an I-H site where TBI conversions appear to be quite common.
EDIT: Just now looking at the attached diagram I see the solution to my timing control situation.
TrailBeast
AKA Mopars4us on Youtube
Sweet, you are going to like how it starts and runs.
Don't forget to regap the plugs to at least .045
straightlinespeed
Sometimes I pretend to be normal
Ohhhh ya! Thanks!
I pulled the complete under hood wiring harness form the 1990 5.7L GMC donor. I replaced the original under hood wiring harness with the gm one. I ran the gm harness through original mopar bulk head location. Removed connection to the Amp meter, Im working on the volt meter conversion for dash. I added an extra fuse box for ECU power coming off a 60amp relay controlled by Ing switch that provides power to coil, fuel pump relay, heated O2 upgraded to a 70 amp Denso alt. I have mounted the ECU on the steering column support. Photos are posted on this site and at EarlyValiantandBarracuda site.
BinderPlanet.com is the best place for more information.
BinderPlanet.com is the best place for more information.
Using the GM HEI module outside of it's dizzy, just bolted to a fender liner or what-not, had always bugged me from a corrosion potential position. Here on the Coastal Desert I've got to consider such things. One could argue that the GM dizzy isn't a sealed container for the module and I'd agree, but it must be good enough elemental shielding because corrosion isn't a usual complaint.
I'm liking this mod because it provides about the same amount of shielding from the elements as a GM dizzy does, maybe more and it's cool because it's not what people who see it think it is. Years ago (~1988 ) I put a Toyota EI module in one of those old 70's era aftermarket CD Ignition housings and converted the dizzy to the Toyota inductive pick-up too. Looked like an old points driven CD ignition, but was something far better.
As to the TBI wiring, there are many, many wiring diagrams out there suitable for the conversion. The 7747 ECU is the most common and pretty much the only ECU used in swaps. A simple search on the topic will turn up more info than is useful. I have the complete system from a 2.8L GM V6 that I'm working towards installing on my 170ci (2.8L) slant. The biggest issue for me is that I don't want the ECU to have control of the timing at first. So how to send the RPM signal to the ECU w/o also allowing timing control or altering the loom is a dilemma that I've got to solve. Eventually the ECU will have timing control (doing one step at a time), so altering the loom isn't very desirable.
Attached is one such diagram that I found on an I-H site where TBI conversions appear to be quite common.
EDIT: Just now looking at the attached diagram I see the solution to my timing control situation.
mopower440
Well-Known Member
I became fed up to wait for my boss make the bracket. So I did plan B and made a plate like 360duster. 360duster your plate looks to be laser cut? It looks good.
Next thing is to paint the casing black.
I know this is an old thread. Where did you get the aluminum plate?
67dartgtgo
Well-Known Member
Has anyone seen this yet?
PerTronix to Feature its New Flame-Thrower HEI III Module at SEMA
Flame-Thrower® HEI III 4-Pin Module
Available for all popular GM applications, the new Flame-Thrower GM HEI III 4-Pin Module features multiple sparks through the entire rpm range and includes an integrated digital REV limiter with LED feedback for precise RPM setting. Fool-proof control eliminates engine damage when rpm goes out of control from a missed shift or excessive wheel spin.
The new module incorporates all the features found in Pertronix’s very popular Ignitor III points replacement module including adaptive dwell, peak current control for increased coil performance, sparking timing adjustment at high rpm to compensate for electronic delay, increased energy at startup for quicker cranking, and built-in reverse polarity and over current protection.
Modules are sold separately and will fit any 4-pin GM large cap distributor. Flame-Thrower distributors and tune-up kits can also be ordered with the new HEI III module.
PerTronix to Feature its New Flame-Thrower HEI III Module at SEMA
Flame-Thrower® HEI III 4-Pin Module
Available for all popular GM applications, the new Flame-Thrower GM HEI III 4-Pin Module features multiple sparks through the entire rpm range and includes an integrated digital REV limiter with LED feedback for precise RPM setting. Fool-proof control eliminates engine damage when rpm goes out of control from a missed shift or excessive wheel spin.
The new module incorporates all the features found in Pertronix’s very popular Ignitor III points replacement module including adaptive dwell, peak current control for increased coil performance, sparking timing adjustment at high rpm to compensate for electronic delay, increased energy at startup for quicker cranking, and built-in reverse polarity and over current protection.
Modules are sold separately and will fit any 4-pin GM large cap distributor. Flame-Thrower distributors and tune-up kits can also be ordered with the new HEI III module.
67dartgtgo
Well-Known Member
It has the rev-limiter adjustment right on top. Looks like you can set it with a screw driver.
The OEM housing has a heat sink on the top. Yeah its kinda primitive in design but since it is there... Why not take advantage ? There's a couple ways to get the heat from the bottom of the GM module into that heat sink. Maybe its not worth the effort.
Time will tell.
Time will tell.
mopower440
Well-Known Member
The OEM mopar housing? where?
That shallow aluminum channel piece, usually clear or gold anodized, is a heat sink for that exposed device (transistor?) in the middle of it.
mopower440
Well-Known Member
ah i see.. how can i do this..? If i screw the gm module to the front wall of the mopar unit, the screws will be sticking out the front and be visible..
KitCarlson
Well-Known Member
Put lock nuts on them, cars have many visible nuts.
sireland67
Well-Known Member
I don't even know if the GM module has a bare metal area on its bottom for heat dissipation. If it does, a heat sink compound could, if not should, be applied to any mounting surface. As for your screw showing concern... they wouldn't show any more than what is shown on your bottom plate.
I'm not saying "I see fault in what you've done" or trying to build a better mouse trap. Just coffee talk.
I'm not saying "I see fault in what you've done" or trying to build a better mouse trap. Just coffee talk.
GM HEI's not only have a metal bottom on them, but thermal conducting grease is an absolute requirement. Some should come with a new module. For a used one find a tube of "Arctic Silver." Something like copper bearing anti-seize will not work. <- That's experience talking there. Worked for a short while and then made me really late to work. From that experience I would also strongly recommend NOT mounting it to the engine.
TrailBeast
AKA Mopars4us on Youtube
Radio shack carries thermal compound, and it's where we get ours for our HEI kits.
The UCU's can easily handle 200+ degrees, but they MUST have a way of disipating the heat buildup from the electronics inside them.
This is where the thermal compound comes in because it transferes that heat to the device it is mounted to.
They can even be mounted directly to body metal as long as the thermal compound is between it and the metal and there is a fair amount of surface contact.
There are two things that make putting them in a Mopar box a bit of a challenge and those are keeping the box stock looking (the point, right?)
And getting the ECU mounted inside there with a good reliable ground.
I found that using wire and a bolt/nut work best for the grounding of the ECU because you either need to put extra screws through the box (not stock looking) or use the same screws that mount the transistor and heatsink.
The screws that mount the transistor and heatsink are too short and large around to be useuable for this, and longer/different screws don't look stock.
You can however use the stock screws and put an eyelet for a wired ground to the case, and machine screws to connect it to the bolt holes on the HEI ecu.
It will still need to be in contact with the Mopar box case or separate heatsink with heatsink compound.
Also once you take all the old crap out of the original box the transistor mounting screws are now too long unless you use spacers inside the box, and when you doo that it takes up the room needed for a heatsink capable surface.
I finally conceded and just let the screws look longer than factory. (lesser of the evils)
Dealing with the pins for the harness connector is fun too, but epoxy works well for this as I wasn't going to leave part of the original electronics board in there to hold them in place.
Without part of the original board in there, they need to be stabilized a different way.
The UCU's can easily handle 200+ degrees, but they MUST have a way of disipating the heat buildup from the electronics inside them.
This is where the thermal compound comes in because it transferes that heat to the device it is mounted to.
They can even be mounted directly to body metal as long as the thermal compound is between it and the metal and there is a fair amount of surface contact.
There are two things that make putting them in a Mopar box a bit of a challenge and those are keeping the box stock looking (the point, right?)
And getting the ECU mounted inside there with a good reliable ground.
I found that using wire and a bolt/nut work best for the grounding of the ECU because you either need to put extra screws through the box (not stock looking) or use the same screws that mount the transistor and heatsink.
The screws that mount the transistor and heatsink are too short and large around to be useuable for this, and longer/different screws don't look stock.
You can however use the stock screws and put an eyelet for a wired ground to the case, and machine screws to connect it to the bolt holes on the HEI ecu.
It will still need to be in contact with the Mopar box case or separate heatsink with heatsink compound.
Also once you take all the old crap out of the original box the transistor mounting screws are now too long unless you use spacers inside the box, and when you doo that it takes up the room needed for a heatsink capable surface.
I finally conceded and just let the screws look longer than factory. (lesser of the evils)
Dealing with the pins for the harness connector is fun too, but epoxy works well for this as I wasn't going to leave part of the original electronics board in there to hold them in place.
Without part of the original board in there, they need to be stabilized a different way.
mopower440
Well-Known Member
ok need some help with this. Using the 8 pin doesnt leave much room inside the empty mopar box, no way to mount the 8 pin to the box and use the mopar heatsink. SO, i am making a heatsink that will bolt to the firewall and stay there, and the HEI unit will screw to it, then the empty mopar box will cover it and use its original bolts to the firewall. Now, i have 2 pieces of aluminum i am using for a heat sink. I want to stack them and bond them together somehow so it will be one thick piece, and plus, it will let the plastic channel of the HEI unit hang over the edge so it will sit correctly..
How can i bond these 2 pieces together good and tight so heat will transfer from one to the other? Plus after bonding them, i need to drill the holes and tap them to mount the HEI unit.
2 pieces need bonded together somehow..
once bonded together, the HEI unit will mount on them like this
The heatsink will be bolted to the firewall with the HEI and the mopar box will just cover it using its original bolts
So, If i sandwiched some heatsink compound between the 2 pieces of aluminum, what can i use to bond the 2 pieces permanantly?
How can i bond these 2 pieces together good and tight so heat will transfer from one to the other? Plus after bonding them, i need to drill the holes and tap them to mount the HEI unit.
2 pieces need bonded together somehow..
once bonded together, the HEI unit will mount on them like this
The heatsink will be bolted to the firewall with the HEI and the mopar box will just cover it using its original bolts
So, If i sandwiched some heatsink compound between the 2 pieces of aluminum, what can i use to bond the 2 pieces permanantly?
Why not just clear bore the top one and tap the bottom one ? Chamfer the edges, check flat. Another dose of compound between the two will do the rest.
mopower440
Well-Known Member
well, each one is not very thick, so i dont think tapping just one will hold. They are 1/8 inch thick each..
#6-40 will give you 5 threads in a eighth. I guess that would require shoulder screws.
2 pieces tapped causes a jamb nut effect in the threads when tightening.
2 pieces tapped causes a jamb nut effect in the threads when tightening.
mopower440
Well-Known Member
so you think that tapping the 1/8 will be enough? If so, i have the original small bolts that held the HEI module onto the GM distributor, do you know what tap to get to use these original bolts?
I have no clue what the factory used. Something metric is my best guess.
TrailBeast
AKA Mopars4us on Youtube
I would grind off the lip of the ECU and just use the one peice of aluminum with taper head machine screws from the underside up to mount the ECU with nuts on those screws.
This way you only need one peice and it would also give a good ground when you screw it to the body metal.
Then tuck your wires into the underside of the Mopar box and mount it over the ECU.
This way you only need one peice and it would also give a good ground when you screw it to the body metal.
Then tuck your wires into the underside of the Mopar box and mount it over the ECU.
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