An observation on aftermarket coils

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Erik Larson - Idaho
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Joined: Sun Jan 06, 2019 7:38 pm
First Name: Erik
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* REQUIRED* Type and Year of Model Ts owned: 1919 Roadster Pickup, 1923 Touring, 1927 TT, 1914 Touring, 1926 TT C cab, 1924 Fordson F
Location: Emmett, Idaho
MTFCA Number: 49553

An observation on aftermarket coils

Post by Erik Larson - Idaho » Tue Aug 25, 2020 11:34 pm

I thought this information might be of interest ....

The following pictures and information relate to some of the aftermarket coils sold by at least one of the vendors. You've seen them before. They are easily identifiable. *Note; this observation was made on a brand new set that was never interfered with after arriving in the mail. (Unfortunately, this is not a unique occurrence. I have made this same observation on approximately 50 other coils of the same type.)
Cons;
The boxes are not the same size as the Ford coils. (see pictures) They are often smaller, in every dimension. Shim, shim, shim.
Instead of wood or glass to separate the capacitors from the windings, they use cardboard.
There is often no tar (or very little tar) in the cavity covering the capacitors ... leaving them susceptible to oxidation, corrosion, and vibration.
The points are often misaligned with wildly varying point gaps and upper cushion spring gaps.
They are not match-tuned. i.e. They are all drawing different current, resulting in terrible fire-timing. And, one was double-sparking.
They have incorrect value capacitors installed.
Each capacitor I tested in these coils tested differently. And, each one tested out-of-range.
Pros;
They actually functioned in the car I tested them in. The car ran ok. However, based on the capacitors alone, these coils likely wouldn't last very long. I've had them fail on my bench several times in the past for no apparent reason.

I hope this information has been informative.
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A Whiteman
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Re: An observation on aftermarket coils

Post by A Whiteman » Wed Aug 26, 2020 5:32 am

Hmm, funny thing is my buddy has just had to adjust a set Sunday last - the tensions on the bridges was too high so little to no spark. And yes, shim, shim shim.
Not made in the USA?


Adam
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Re: An observation on aftermarket coils

Post by Adam » Wed Aug 26, 2020 9:57 am

These are a “carryover” of the “KW Brand” coils made since the 1950’s. The manufacturer is basically making them pretty much the same as they have always been made. In other words, they are a “medium quality” coil. Some work good, some are a little flaky. The capacitors generally don’t last very long but usually are okay for a couple hundred miles.

Original FORD script coils rebuilt by a competent rebuilder are generally always of better quality AND less expensive. New “KW Coils” from Fun Projects utilized good used Ford windings and were also of very good quality.

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Topic author
Erik Larson - Idaho
Posts: 47
Joined: Sun Jan 06, 2019 7:38 pm
First Name: Erik
Last Name: Larson
* REQUIRED* Type and Year of Model Ts owned: 1919 Roadster Pickup, 1923 Touring, 1927 TT, 1914 Touring, 1926 TT C cab, 1924 Fordson F
Location: Emmett, Idaho
MTFCA Number: 49553

Re: An observation on aftermarket coils

Post by Erik Larson - Idaho » Wed Aug 26, 2020 11:36 am

Adam,

I agree with all except one point ... these have very little in common with the aftermarket KWs. Their construction is completely different. I think the KWs were excellent quality coils, and I would hesitate to even rate these as medium quality. :)


Ron Patterson
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Re: An observation on aftermarket coils

Post by Ron Patterson » Wed Aug 26, 2020 4:24 pm

Erik
This subject has been discussed many times on this Forum over the last 25 years.
These coils are made by a company in Oregon and have went through many iterations (of corrections) over the years. Hence the variations you are seeing.
The first problem was the size of the boxes were not like original Ford coils. That problem has since been corrected, but many of them made with this issue are floating around in Model T owners hands.
The earlier ones also used Metalized Mylar capacitors, which as you pointed out, didn't last very long. That too was corrected (for a while) when another later batch with (incorrect) capacitors was introduced which created another round of bad coils floating around in the hobby.
I am told by a reliable source that this most recent problem have also been corrected. I do not know I simply do not have the time to determine which vintage I am seeing at any given time.
I agree with you about original Ford and FunProjects coils being the best place to start, but the later are not currently available.
Ron

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Topic author
Erik Larson - Idaho
Posts: 47
Joined: Sun Jan 06, 2019 7:38 pm
First Name: Erik
Last Name: Larson
* REQUIRED* Type and Year of Model Ts owned: 1919 Roadster Pickup, 1923 Touring, 1927 TT, 1914 Touring, 1926 TT C cab, 1924 Fordson F
Location: Emmett, Idaho
MTFCA Number: 49553

Re: An observation on aftermarket coils

Post by Erik Larson - Idaho » Wed Aug 26, 2020 5:45 pm

Thanks Ron. FYI; these coils were brand new, so they may still be having some issues.

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