Author Topic: Ignition Coils - Cheap quick and plentiful  (Read 1818 times)

Offline DD805

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Ignition Coils - Cheap quick and plentiful
« on: December 01, 2017, 03:57:45 AM »
 Ignition Coils - Cheap, quick, easy and plentiful.

I posted this article on the other forum several years ago and when I checked a couple of days ago it had almost 25,000 reads so I thought it might be of interest here too.

Looking for a good source for coils for your model engines? Here is what I have been using since about 2011. They are cheap, easy to make and extremely plentiful. Millions are just waiting for you in your local junkyards.

They are the COP ignition systems used on all modern cars since the late 1980s. COP stands for Coil-Over-Plug or Coil-On-Plug, where each plug has its own coil. They are small, easy to modify for your models and powerful enough to meet most needs.

I bought a set of eight COPs for a 1980's Ford van from a local junkyard for $40 USD. That translates to a mere $5 per coil. If you don't need eight then get a set from a 6 or 4 cylinder engine. I suspect yards that allow you to pull your own parts will sell you one at a time.

Update Dec 2017. I just purchased 4 more COPs today from the same auto yard and they cost me  $10 each. I think I can do better on ebay. I will do a follow-up post when I have more info.



The first picture shows a COP just as it came from the yard. The second picture shows it with the boot removed. Remove the boot simply by grabbing and pulling it firmly. Sometimes it may take a slight twist.

The next step is to remove the spring. More rocket science, grab and pull, it will stretch out a bit but should pull off easily. You are now in possession of a basic ignition coil.


 If you look into the hole where the spring was you will see a flat spade type of connector. This is where you will connect the wire to the spark plug. Look close at the picture and you will see the female connector I used to attach to the wire and which slides over the spade connector. I don't know what they are called but I got mine from one of those electrical connector packs you can get at most hardware stores.
 
A COP I bought today is from a Toyota Camry and when I removed the boot I found a connector that looks like the cap on a sparkplug. There obviously are a lot of variations depending on make and model of the vehicle.
 
The next picture is the finished coil ready to install. Total time, about ten minutes. Not shown are the wires that come from the electrical source. On the COPs I got the wires were missing so I had to make them. Not a big deal, just a bit if a pain. Be sure when you get yours that you get them with the lead in wires attached. Save some time.
 

I have experimented with this coil some and found it works with any engine I have and does the job whether 6V, 12V or 9V. I ran an engine at 2011 GEARS show using 9V batteries.
It is important to understand that there are a lot of different COP styles other than the one I show here. COPs come in three major configurations, two wire, three wire and four wire. What I have here is the two wire version. I do not know how the three and four wire COPS work.

Finally, I hope that others who try these COPs for model coils will post their findings for the benefit of our hobby.
 
Karl

Offline Admiral_dk

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Re: Ignition Coils - Cheap quick and plentiful
« Reply #1 on: December 01, 2017, 11:18:32 AM »
Nice trick  :ThumbsUp:

I would expect a tree wire to be Power, Ground, Control of the internal IGBT switch and a fourth wire to be an Feedback signal to the ECU.
I've read that most new ones have five, six or more wires to connect to the ECU so the ECU can measure Current, Power, and Temperature and some even Knocking/Ping - all in order to improve reliability of the engine and lower emissions, but that might just be here in Europe + Japan  :)

Offline GordonL

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Re: Ignition Coils - Cheap quick and plentiful
« Reply #2 on: December 01, 2017, 12:58:20 PM »
i have been using them for some time and I have had good success with them. I purchased a set of eight for a Ford from eBay for about $35. The spark plug wire takes a standard spade connector. The coil connectors take a special connector which I have not been able to find. I just cut off the outer shield and solder wires to the now exposed pins.

Offline cwelkie

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Re: Ignition Coils - Cheap quick and plentiful
« Reply #3 on: December 01, 2017, 01:44:43 PM »
FWIW - Connectors for these coils (and the coils themselves) are readily available through AliExpress.

Offline DICKEYBIRD

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Re: Ignition Coils - Cheap quick and plentiful
« Reply #4 on: December 01, 2017, 08:30:11 PM »
Very interesting post, thanks! :cheers:

If you don't mind sharing, are you switching the coils with mechanical points or electronics?  What primary voltage are you using?  I have saved a few of them but never went any further.  You've piqued my curiosity!
"Accuracy is the sum total of your compensating mistakes."

"The thing I hate about an argument is that it always interrupts a discussion." G. K. Chesterton

Offline DD805

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Re: Ignition Coils - Cheap quick and plentiful
« Reply #5 on: December 01, 2017, 11:42:45 PM »
Gordon,
 Nice to know you are already using them. I did some research after my post and found that you can easily get the Ford coils from ebay for about six to seven dollars. Brand new, not greasy and oily. I found you can get the wire connectors on ebay if you search on the value 'coil connector Ford'. They even come with pigtails sometimes. They cost only about three to four dollars when bought in packs of eight. Amazon also carries this stuff. I pulled the connector off the Ford coil I just bought and it looks just like the ones on ebay. Apparently Ford and others used this COP design from about 1986 to 2011 on many models. I am not going to bother using coils other than the Ford ones because they are so cheap and plentiful.

Dickeybird,
 Glad you asked this question as I am preparing another post showing the transistor ignition system that I use. I have used them with 6v 9v and 12v. I use mechanical points but Hall Effect switches would work but are not needed. I use paperclips for contacts.

Offline GordonL

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Re: Ignition Coils - Cheap quick and plentiful
« Reply #6 on: December 03, 2017, 06:49:52 PM »
Karl:
Thanks for the tip on the connectors. The only thing I had found before was as a Ford part. I just ordered a set of eight.