As reported Here, I was recently stranded with a cooked ignition module.
Not wanting to go through this process again, I searched the archives for ways of cooling down the ignition module on my '86 GT. Although I found posts from PFF members talking about the possiblility of using heatsinks mounted on the underside of the distributor, I was surprised that I didn't actually find any posts by someone who had done it. I obviously then wasn't able to find any pictures of a modified distributor to see how it might've been accomplished.
So I did it my way.
I used a heatsink from some ancient CPU that was about the right size for the job. Longer cooling fins might've been better, but you gotta use what you have on hand.
I ground down all bumps on either side of the distributor base, and drilled large enough holes for machine screws to pass through. I then drilled and tapped the heatsink to accept the four screws, two of which go through the ignition module as well. Thermal paste was applied to the underside of the ignition module as well as to the topside of the heatsink.
The way I assembled everything, the ignition module can still be changed with the distributor in the engine. Hoping I won't have to do it again though.
Yes, the screws look goofy sticking down so far, but I figure the more surface area the better for cooling. They won't even be noticeable once the distributor is installed.
If you have any questions, I'd be pleased to answer them.
I noticed afterwards how much the camera flash shows up the ground aluminum dust on the heatsink in some of the shots!
[This message has been edited by Patrick (edited 10-27-2008).]
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02:39 AM
PFF
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WhiteFormula Member
Posts: 155 From: Lakewood, Il Registered: Oct 2004
Sure can't hurt at all. Would think it would drop the temp a few degrees as long as the air around the dist. stays cooler than the inside of the dist. A black sink actually cools a tiny bit better than any other color. Very small amount but every bit helps (Light exposure has nothing to do with it..)
However the biggest gain would be from heat sink compound between the sink and the dist housing. I can't tell if you have compound between them or not. I would add some if you have not. Any electronic store should carry a tube of compound.
[This message has been edited by Dodgerunner (edited 10-27-2008).]
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07:41 AM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
Ya ya... I knew someone would comment on that which is why I mentioned it earlier.
quote
Originally posted by Patrick:
Yes, the screws look goofy sticking down so far, but I figure the more surface area the better for cooling. They won't even be noticeable once the distributor is installed.
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12:32 PM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
However the biggest gain would be from heat sink compound between the sink and the dist housing. I can't tell if you have compound between them or not. I would add some if you have not. Any electronic store should carry a tube of compound.
Rory, didn't you read my post?
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Originally posted by Patrick:
Thermal paste was applied to the underside of the ignition module as well as to the topside of the heatsink.
You can actually see it squishing out in the second-to-last picture.
I'll be installing the distributor in an hour or so. Hope it works!
That should definitely help the heat problem. The screws will just give that much more heat dissipation. The more surface area the better. Good use of old parts lying around.
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02:09 PM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
Has anyone remote mounted the module to isolate it away from heat, if my wacky idea is feasible?
Reading through the archives, I came across several posts about doing just that. The ignition module needs to mounted in a location preferrably cooler than where it normally resides. Obviously the wiring would need to be extended, and some of the discussion I read addressed the possible need for shielded wiring that could withstand high heat.
quote
Originally posted by sparx22:
Is heat an issue with 4 and 6 cylinder alike?
Anything electronic that produces it's own heat as a by-product (such as the ignition module) needs to be cooled. Being cooked eventually leads to component failure. If the Dukes use something similar (or the same) as the V6 ignition module, then the cooler it is the better as well.
[This message has been edited by Patrick (edited 10-27-2008).]
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02:45 PM
PFF
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Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
Id think anything would help. Too bad theres nothing to circulate some air past your heat sink. Since it just sets there in hot air over the intake, its possible that it may actually absorb more heat and transfer it to the module. Im just being the pessimist, not knocking your ingenuity.
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03:48 PM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
Too bad theres nothing to circulate some air past your heat sink. Since it just sets there in hot air over the intake, its possible that it may actually absorb more heat and transfer it to the module.
From what I understand, the ignition module produces heat a whole lot hotter than the air in the engine compartment. That's why GM mounts the ignition module on the metal bottom of the distributor in the first place. This allows heat from the module to be released to the engine compartment from the bottom of the distributor. I'm just helping the distributor do this task a bit (a lot?) more efficiently by installing the heatsink.
It's very similar to what goes on in our computers and the way the processor is cooled (minus the fan). Yes, a fan on the heatsink might help some, but it’s not like the engine compartment is sealed. There is air flow, especially when the car is in motion.
I'm just putting the distributor back in now. Reports to follow.
It looks like a great idea but you could have gone 2 steps farther and introduced the upgraded pole piece and copper cap along with having the magnetic pickup media blasted to reduce all that rust that is on their. I have found that to be a dramatic improvement over stock. I have a thread somewhere on the forums over this. Nice idea though. I wonder if you can tap one of the wires and get power to power a small cpu fan under their too?
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05:34 PM
Curlrup Member
Posts: 2590 From: Havre De Grace, MD Registered: Apr 2007
It looks like a great idea but you could have gone 2 steps farther and introduced the upgraded pole piece and copper cap along with having the magnetic pickup media blasted to reduce all that rust that is on their.
Hey, this is what it looked like the first time I took it apart as I reported Here.
My plan is to get another distributor with the newer style pole piece. This distributor (which now has a new ignition module, pickup coil, cap and rotor) will eventually be my spare.
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Originally posted by mmeyer86gt/gtp:
I wonder if you can tap one of the wires and get power to power a small cpu fan under their too?
quote
Originally posted by Curlrup:
Well done, my thoughts too, could you fit a small fan under there?? A little clip on jobby you would use on a computer.
I’m doubtful that a CPU fan designed for computer use would be able to withstand the harsh environment of life in a Fiero engine compartment. But yes, a small 12V fan of some sort would be great if it was tough enough, especially while the car is sitting in one spot idling. Keep in mind though that this '86 GT does have the trunk fan which is aimed right at the coil and distributor.
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07:15 PM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
holy crap, exactly what part is that? that looks corroded beyond use.
------------------ 1987 Fiero GT built by my brother, merlot566jka, 3500 LX9 from 06 Malibu, WOT-TECH.com 1280 grind stage 3 cam, LS6 valve springs, 1227730 ECM conversion, Darrel Morse solid aluminum cradle mounts, Truleo headers modified to fit the 3500, 36# inectors, 70mm 4.3 throttle body adapted to 3500 intake, ported heads, upper and lower intakes, lightly polished, tcemotorsports.com crank trigger wheel, CenterForce dual friction clutch, Flowtech Afterburner muffler, 2.5" piping, cat deleted, EGR deleted, SinisterPerformance tuning, C6 Corvette exhaust tips. projected to be 35 MPG with a guesstimate of 250 hp at the motor
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10:40 PM
PFF
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Oct 28th, 2008
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
holy crap, exactly what part is that? that looks corroded beyond use.
That was my reaction as well when I first took the top off the distributor a few months ago.
Keep in mind though that what you see there is what you see in the top picture in this thread (after being cleaned up a bit). The distributor itself works fine. I didn't even change the awful looking pickup coil until this week. Figured I may as well change it since I needed to change the ignition module anyway.
[This message has been edited by Patrick (edited 10-28-2008).]
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12:08 AM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
I appreciate the suggestion, but no, I still prefer to use screws.
The ignition module is held on with screws from the factory, and the four screws I've used really clamp the heatsink (and module) tightly to the distributor base. This insures good metal to metal contact and superior heat dissipation. That’s the theory anyway.
[This message has been edited by Patrick (edited 10-28-2008).]
In the building and overclocking of computers for quite some time we used epoxy TIM to mount heat sinks permanently to mosfets that regulated voltage on our motherboards. These mosfets were getting super hot and they needed to be modded to insure life and maintain performance.
There are numerous types available, some ceramic bases some are silver based. The material served well in keeping things cool. If I decide to add a heat sink to my V6 I would opt for the bonding TIM to improve heat transfer. At least it is worth a try.
I hope yours works well you did a nice job on it. A fan would help but as mentioned above life of the fan might be short due to heat and dirt present in the engine compartment. sparx22
[This message has been edited by sparx22 (edited 10-28-2008).]
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01:06 PM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
If I decide to add a heat sink to my V6 I would opt for the bonding TIM to improve heat transfer.
When you say "to improve heat transfer", are you suggesting that bonding TIM is superior to non-binding TIM in regards to heat transfer?
The reason I ask is because I need to make it clear (if there's any confusion) that I did indeed use Thermal Interface Material between the heatsink and the distributor base.
I don't think it would make a bit of difference whether the TIM is binding or non-binding in regards to heat transfer. However, what does make a huge difference with heat transfer is the amount of actual metal to metal contact, rather than metal to TIM to metal contact.
For this application, I honestly believe using screws to clamp the metal surfaces together is superior hands down to simply "gluing" the heatsink with bonding TIM to the distributor base. Keep in mind the distributor base is not as flat and even as a computer component such as a CPU or MOSFET. There needs to be a way to force as much of the metal surfaces together to make good contact. I believe the use of four screws in my modification to clamp the heatsink to the distributor base does this quite well. And two of those screws actually aid in heat transfer themselves as they go through the hot ignition module and directly into the heatsink.
Sparx, I appreciate the fact you've brought up another option. Although I personally don't believe it would work as well, it certainly promotes discussion regarding the pros and cons of different methodologies. Thanks.
[This message has been edited by Patrick (edited 10-28-2008).]
I do agree that the base of the dist in no way is as smooth as a cpu and cpu hest sink. But, findings (in CPU cooling) have shown that using excessive amounts of TIM have become more of an insulator than a conductor of heat.
There would need to be a heat sensor installed in order to monitor temps to prove this, and of course ambient would need to be monitored as well. But yes I would think that the use of a quality bonding (epoxy TIM) would be superior in heat transfer. It makes more sense that heat transfer would be greater (conductivity) through solid mass. The difference may not be significant however, and testing with temp probes would be required to prove my theory.
I have gone through the mistake of apply excessive amounts of TIM on a cpu where it mates to a cooling unit, but as you stated those are very smooth and flat surfaces compared to the distributor.
The fact is what you have done most definitely will improve cooling. Are you going to try a 12 volt fan? I have an 80 mm fan I can donate. sparx
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06:09 PM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
I never suspected that. Honestly, I appreciate you have a different spin on the process. This exchange of info is healthy.
quote
Originally posted by sparx22:
Are you going to try a 12 volt fan? I have an 80 mm fan I can donate.
Thanks for the offer, but I have all kinds of CPU/case fans here. I’m not going to try one though because I really don’t think they’d stand up to the heat and/or to the road grime in an engine compartment.
quote
Originally posted by sparx22:
But yes I would think that the use of a quality bonding (epoxy TIM) would be superior in heat transfer. It makes more sense that heat transfer would be greater (conductivity) through solid mass.
Sparx, I’m trying to see this from your perspective. Are you saying that when TIM with epoxy hardens to a “solid mass” that it’s more efficient at transferring heat than non-binding TIM which turns from a paste over time to more of a powder?
If so (and I’m not conceding that this is correct ), then the best procedure might be to use binding TIM on the heatsink which is clamped in place by screws!
However, I’m still not convinced that binding TIM is any better than non-binding TIM when it comes to transference of heat. Supply a link!
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06:46 PM
larryfiero Member
Posts: 40 From: wheat ridge colorado usa Registered: Apr 2002
Patrick, I have mounted my ignition module in a remote area on my 2 Formulas and with great success. I too had gotten tired of breaking down and replacing a mod in heavy traffic. I had reached a point selling my Fieros because of the heat problem. So, long ago I spent an entire weekend studying the engine compartment and saw why my modules had such a short life span.
Back then being new to PFF I found the archives and read anything on remote mounting of a module. After reading everything, I jury rigged a prototype and to my surprise the car ran just fine. My first discovery was the heat sink I was using was too small. It was apparent that the mod produced a lot of heat. Next, with an old mod that I was going to throw away, I wired it up and with no heat sink started up the car and found out real quick how much heat it produced. It’s at this point, I knew I could save my cars.
Long story short, I have not replaced a mod in 3 years. The mod is mounted in the trunk of one Formula and the other Formula has the mod located in an open air space behind a quarter panel. 21/2 years on that one.
With that working for me, I looked at the ignition coil and found the heat breaks down the coil to the point it causes backfires. So, I mounted it in a open air space on the rear bumper behind the drive rear tire and just above the exhaust tips.
I’ve been driving with confidence, knowing that I am not going to be breaking down!!!
If you are interested in pics, let me know.
Larry
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07:57 PM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
My first discovery was the heat sink I was using was too small. It was apparent that the mod produced a lot of heat. Next, with an old mod that I was going to throw away, I wired it up and with no heat sink started up the car and found out real quick how much heat it produced.
Larry, that right there is INVALUABLE information! There are many people who don't believe that the ignition module produces much heat. You've provided first-hand information that this is not the case. Thanks so much!
If you've got pictures, I'd love to see them. Post them here if you like. Describe the type of wiring you used.
If mounting the ignition module remotely is the best way to go, I'm all for it!
Patrick, I have mounted my ignition module in a remote area on my 2 Formulas and with great success. I too had gotten tired of breaking down and replacing a mod in heavy traffic. I had reached a point selling my Fieros because of the heat problem. So, long ago I spent an entire weekend studying the engine compartment and saw why my modules had such a short life span.
Back then being new to PFF I found the archives and read anything on remote mounting of a module. After reading everything, I jury rigged a prototype and to my surprise the car ran just fine. My first discovery was the heat sink I was using was too small. It was apparent that the mod produced a lot of heat. Next, with an old mod that I was going to throw away, I wired it up and with no heat sink started up the car and found out real quick how much heat it produced. It’s at this point, I knew I could save my cars.
Long story short, I have not replaced a mod in 3 years. The mod is mounted in the trunk of one Formula and the other Formula has the mod located in an open air space behind a quarter panel. 21/2 years on that one.
With that working for me, I looked at the ignition coil and found the heat breaks down the coil to the point it causes backfires. So, I mounted it in a open air space on the rear bumper behind the drive rear tire and just above the exhaust tips.
I’ve been driving with confidence, knowing that I am not going to be breaking down!!!
If you are interested in pics, let me know.
Larry
I am interested in images, I referred to this up the page. Glad to see it has been done.
Do the dukes with a distrubitors have these , and are they also prone to heat failures also? Seems like all the V6 guys are having these problems. Joe Crawford
[This message has been edited by josef644 (edited 10-28-2008).]
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08:50 PM
PFF
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Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
Sparx, where exactly does it state in your links that binding TIM is superior to non-binding TIM in regards to heat transference? I see nothing along those lines.
The only reference to the performance of this particular binding TIM that I could find was the following:
"Greater heat transfer properties than with thermal type tape."
Am I missing something?
[This message has been edited by Patrick (edited 10-28-2008).]
Sparx, where exactly does it state in your links that binding TIM is superior to non-binding TIM in regards to heat transference? I see nothing along those lines.
The only reference to the performance of this particular binding TIM that I could find was the following:
"Greater heat transfer properties than with thermal type tape."
Am I missing something?
That's all I can find at this time.
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09:51 PM
steve308 Member
Posts: 4001 From: Stafford VA Registered: Jan 2008
Larryfiero --- Please post pics of your remote locations and the harnesses you built to reach the locations. Patrick -- suggest a tetanus shot prior to handling the distributor again!!!!!! Thought mine looked bad but yours had mine beat hands down!
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10:04 PM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
I would be more than happy to post pics of both the ignition module and ignition coil relocation project. I will not have time get pics until Saturday but I am hoping sooner.
Until then, the next time your out for a spin, stop and put you fingers on the underside of the distributor heat sink and get a quick idea how much heat is on the module.
Just a note on what I believe causes the mod and coil to fail: With heat from the crossover exhaust pipe, the internal engine heat transferred up through the distributor shaft, the small surface are of the distributor heat sink, both the catalytic converter and muffler positioned high in the engine compartment, and the main factor being almost no cool air flow across or near the distributor.
With so many negatives on the heat problem, I was left with a choice of selling both of my girls or find a solution on my own. Well I did find a solution and I hope it works for someone else. I worked a lot of days off to finding a way to never break down again. I really didn’t want to sell my girls. Besides, I am like you guys. You love it when someone filling their tank walks over from a couple pumps over to ask you “what kind of car is that?” ,“ how old is it?” or “that is a beautiful car”. And you love when someone has a story to tell you about a Fiero. The best story I ever heard was when a group of people were looking over my car at a motel parking lot and while chatting with them they told me this story. “ the very first fiero sold in Colorado Springs, Colorado was sold to a man who’s name was and you are not going to believe this RED FIERO!” The local paper carried the story . Hope to find it someday.
Any way I never sold my cars and I don’t worry anymore about breaking down. My modification has worked for me and when you see how I did the wiring, I think you will be surprised how easy it is. I know one of you will out do my set up. See you all on Saturday… Larry
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01:03 AM
Patrick Member
Posts: 37846 From: Vancouver, British Columbia, Canada Registered: Apr 99
Geez Larry, you've been a member here since April of 2002 and prior to this thread you've posted a grand total of SIX times!!!
Why have you been holding out on us? Don't be such a stranger!
I'm sure there are many of us who are looking very forward to seeing what you've done with your ignition module and coil. Don't lose your way back here now.
Geez Larry, you've been a member here since April of 2002 and prior to this thread you've posted a grand total of SIX times!!!
Why have you been holding out on us? Don't be such a stranger!
I'm sure there are many of us who are looking very forward to seeing what you've done with your ignition module and coil. Don't lose your way back here now.
He reads a lot!
[This message has been edited by sparx22 (edited 10-29-2008).]
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10:21 AM
larryfiero Member
Posts: 40 From: wheat ridge colorado usa Registered: Apr 2002
What can I say, I really did read a lot. I spent a lot of time in the Technical Archives. You guys have experienced a lot and done a lot. I learned a lot from you all. When I had t-top issues, I found every photo and lots of information I needed to do my repairs. The only thing that I have done that was different was the relocating the modules and this thread caught my interest. I felt enough time has passed on the prototypes to pass on the information.
I give my word to post more often.
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10:23 PM
Oct 31st, 2008
larryfiero Member
Posts: 40 From: wheat ridge colorado usa Registered: Apr 2002
Ok everyone, I have taken pics of my modifications. I would like to take this new info to a new threaded titled “Ignition Module / Ignition Coil remote relocation.” I should have that posted shortly. Standby.