Question for the coil experts

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Model T Ford Forum: Forum 2012: Question for the coil experts
Top of pagePrevious messageNext messageBottom of page Link to this message  By Bud Holzschuh - Panama City, FL on Saturday, May 19, 2012 - 04:57 pm:

I have 2 K&W coils, 1 ford coil and 1 brass top with no manufacturer noted.

Recently while checking the coils (all have new caps all work fine) I noticed a problem with the spring retaining rivet (the rivet just below the letter D in the diagram below)




The MTFC's electrical book says there should be movement on the upper contact which is controlled by the rivet. Problem is that only one of the K&W coils has the rivet as shown. The remaining 3 coils all have the rivet installed too tightly and there is little or no movement possible on the the upper spring point.

This does not appear to be someone's clumsey attempt at a modification, it appears that the rivet was installed that way when the coils/points were made. It is also not a dirt problem as I have used a thin blade and carb cleaner to clean out the area above and below where the rivet goes thru the spring. The rivet is simply compressed too much to allow any movement on two of the coils and only a few thousandths on the 3rd coil.

So I guess the question is, did the coil manufacturers phase out the upper points ability to delay breaking contact at some point in the coils evolution? Or do I have 3 coils that came from the factory out of spec?

Anyone seen this before? Can it be fixed? Should it be a point of concern?

Thank
schuh


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garnet on Saturday, May 19, 2012 - 05:03 pm:

The cushion spring contact should freely move anywhere from 10 to 20 thousandths Bud. They should also be hospital sterile (clean I mean). The only fix is a new upper contact.

Regards,
Garnet


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ron Patterson-Nicholasville, Kentucky on Saturday, May 19, 2012 - 05:27 pm:

Bud
Proper gap and operation of the coil point upper bridge cushion spring (on all four coils)is the key to the Model T coil/s working correctly on the magneto. Any differences will have a materiel effect on inter-cylinder ignition timing differences and result in poor engine operation.
Ironically, many folks think their Model T runs just fine, till they have the chance to try set of four coils that have been correctly set up on a hand cranked coil tester. I cannot tell you the number of times I've had people tell me "I can't believe how well it now runs" after getting their coils correctly rebuilt.
Get your coils into the hands of a competent coil rebuilder with a proven track record (there are several out there) and you will be surprised.
Ron the Coilman


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Saturday, May 19, 2012 - 06:09 pm:

To answer your question directly Bud I suspect the points that don't work properly are reproductions made sometime after WWII. Who ever was / is making those did / does not know the cushion spring had to move.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ron Patterson-Nicholasville, Kentucky on Saturday, May 19, 2012 - 07:33 pm:

Royce
I answered Bud's second, third and fourth questions first because his first question has no definitive answer.
Ron the Coilman


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bud Holzschuh - Panama City, FL on Saturday, May 19, 2012 - 07:48 pm:

Thanks all, for your expertise.

Ron - I don't have a magneto so that's probably why its running as well as it is.

Royce - Your answer seems most logical as I just don't see it happening anywhere else but at the manufacturer. Hard to believe though that a supplier of parts would just leave that feature off!

Well... time to buy some points as I doubt if these can be fixed. I hope the new K&W points the vendors sell are correct!

schuh


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ron Patterson-Nicholasville, Kentucky on Saturday, May 19, 2012 - 08:16 pm:

Bud
Just so you don't leave this conversation with a mistaken impression, the same is true regardless of whether your operating on battery or magneto.
All the coil points made today are manufactured by the same company. There have been some issues and they are working to correct them, but they can be dealt with.
Give me a call if you run into trouble.
Ron the Coilman


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Leming on Saturday, May 19, 2012 - 09:24 pm:

I have a question - why is the amperage critical to 1.3 amps? I mean I know it should not be any lower, it would be weak. If its higher is that due to a coil points burning issue?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ron Patterson-Nicholasville, Kentucky on Sunday, May 20, 2012 - 09:37 am:

John
1.3 Amps (average reading on an iron vane ac ammeter as used on the hand cranked coil tester) is required because of the internal design of the coil and its ability to produce sufficient voltage to spark the plug under the conditions that exist in the Model T engine. These factors are; primary circuit inductance, ratio of primary to secondary windings, “Q” (merit) of the coil, circuit duty cycle and compression ratio of the engine.
If the current is not controlled the coil will produce a poor spark or excessive heat. Here is a photo of a coil where one of these factors (duty cycle) has been exceeded for an extended period of time by a timer wire shorted to ground.
1
The coil got hot and boiled the internal tar out of the top of the wood box. The same thing could happen if the current were set too high and the coil was driven into saturation.
Significantly lesser current would produce a lower spark voltage and higher current would only produce excessive heat.
Ron the Coilman


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Sunday, May 20, 2012 - 09:49 am:

Ron,

I was trying to answer Bud's question:

"So I guess the question is, did the coil manufacturers phase out the upper points ability to delay breaking contact at some point in the coils evolution? Or do I have 3 coils that came from the factory out of spec?"

The fact is you can still buy brand new coils from some sources that indeed have non - moveable upper points. This is not because of "evolution", it is because of poor quality and / or a lack of understanding by the manufacturer.

Ron I agree with everything you posted, I just wanted to make the point that some of our vendors continue to sell lackluster coils. I don't know of any way to get a good coil that is better than sending you a set of originals to be rebuilt. The original Ford or pre - WWII KW manufactured coils, with new modern capacitors and properly set points, are superior to most anything made new today.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Leming on Sunday, May 20, 2012 - 10:54 am:

Thanks Ron, I appreciate the information. I have a bunch of coils, maybe 20 or so and I want to learn enough to try my hand at a rebuild. Do you have to use tar when you reseal? We often use black hi temp silicone in rebuilding electrolytic caps in our old radio business, and I just wondered. (I rebuild and repair antique radios)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ron Patterson-Nicholasville, Kentucky on Sunday, May 20, 2012 - 11:13 am:

John
I suggest you obtain the three part Coil Rebuilding CD's available from the MTFCA. Everything I know about coil rebuilding is included in those CD's.
Silicone sealant contains acids and can attack electrical connections.
Get .47uF 400 WV film foil capacitors with the proper dV/dT rating from Lang's or FunProjects.
I like to put the coils back the way I found them and they will last another 80+ years. You can obtain a chunk of Type III Steep roofing asphalt at your local roofing supply. Heat it in a coffee can on your barbeque. You can use your wife's stove, but remember you only get away with that once.
Use a hand cranked or StroboSpark coil tester to get 16 individual 1/4 inch sparks at the spark ring and you will be all set.
Good luck
Ron the Coilman


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ron Patterson-Nicholasville, Kentucky on Sunday, May 20, 2012 - 11:22 am:

Just to elaborate on what Royce said.
In addition to rebuilt original coils available from Model T parts suppliers there are three manufacturers of newly made coils being sold.
Make sure any original coils you purchase have been rebuilt by a competent rebuilder. Be aware that two of the new coils made today are very poorly made and fail very quickly. I see these in my shop every day, won't mention any names here, but if you want my advice contact me and I will make you an informed coil consumer.
Ron Patterson


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bud Holzschuh - Panama City, FL on Sunday, May 20, 2012 - 12:46 pm:

Thought y'all might like to look at what started the thread:
This is the K&W upper point plate. It may look like there's a few thousands clearance at the rivet, but there isn't, the rivet is slightly flared. I attempted to clean out with a .001 feeler and carb cleaner - no luck - its tight!







This is the Kingston upper point plate. Same comment goes about the flared rivet - no clearance at all much less the 10 to 20 thousandths that was mentioned.






You can see from the pics that the rivets seem to be factory original and not pounded on by anyone.

Cheers
schuh


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Jablonski on Sunday, May 20, 2012 - 01:49 pm:

Schuh:

Have you tried to put some tension into the cushion spring ?

Added tension will keep the spring on the limiting rivet.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Leming on Sunday, May 20, 2012 - 04:38 pm:

I dont really buy into that cd business. I always think the forum is a place to ask and get answers without spending money. I really dont think this is a place to push ones own products. sorry thats just my take.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ron Patterson-Nicholasville, Kentucky on Sunday, May 20, 2012 - 04:51 pm:

John
Just to clarify my suggestion, I AM NOT PUSH (ING) ONES OWN PRODUCTS!! I defy you to find a Forum post where I am hawking my services.
This was a MTFCA project and I was asked to help.
They paid for and sent a professional TV camera crew to my house and filmed the entire coil rebuilding process over a three day span of time.
I provided all the technical content at no cost just so the knowledge would be passed on others. I get no cut of MTFCA CD sales.
Ron Patterson


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Dufault on Sunday, May 20, 2012 - 04:58 pm:

Hmmm,


Ron read and posted faster than I could find an old thread/statement...

and I still cannot find it.

However, what I was looking for was answered...yes, it has previously been reported that Ron had donated his time and expertise to produce the coil repair videos for the benefit of the hobbiest, as well as the MTFCA.

Actually, I thought I read that there were several others involved...not the least of whom was our dear departed Bruce.

Thanks Ron...and the others - for sharing.

Dave


Top of pagePrevious messageNext messageBottom of page Link to this message  By Joseph Magedanz on Sunday, May 20, 2012 - 06:04 pm:

John L.,
Ron Patterson is one of the most, if the the most, self-less people on this forum and in the hobby. It has been said many, many times before that he gets absolutely no returns from having made those CDs.
I for one am very lucky and glad that he did make them--sharing his hard-won knowledge and expertise for no charge to the MTFCA--so that I could get a start in trying to learn how to rebuild coils. He ain't gonna be around forever (sorry, Ron, no rush...) and then who are we going to turn to for help?
I have benefited many times from Ron's help and I hope that he is willing to stick around for a long time.
Thanks, Ron...and the others--you know who you are.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Erich Bruckner, Vancouver, WA on Sunday, May 20, 2012 - 06:16 pm:

I have learned soooo much from the MTFCA books and videos (as well as from this forum). Some things are understandable with only a read, but sometimes I just gotta see it before it clicks.

I got the best of both worlds by buying the books and my club owns all the videos. One more benefit of being in a club.

Also, Ron is the best with help on the phone if you need it.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Hal Schedler, Sacramento on Sunday, May 20, 2012 - 06:47 pm:

John L, You are WAY off base!!! Ron will help anyone at any time, and his donation to the CD is a good example of it. We have a fantastic library thanks to folks like Fred H.,Ron P., Milt W. and others. If you want to produce good coils the CD is priceless. IMO


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bud Holzschuh - Panama City, FL on Sunday, May 20, 2012 - 07:30 pm:

Bob

There looks like there is some room to bend the spring out, but there is zero clearance. Right at the end of the arrow the rivet has a tiny shoulder so in reality
the spring is riveted tightly to the upper point plate!


One alternate explanation is that the rivet was inserted by hand and before the rivet was peened a small piece of steel 10 to 20 thousandths thick with a u shaped
cutout was supposed to be inserted between the rivet and the spring to insure the clearance needed. Maybe on this day Rosy the riveter forgot to insert the spacer
or it broke off the riveting machine (if automated).

I do wonder just how common this fault is....

Cheers
schuh


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Leming on Sunday, May 20, 2012 - 08:06 pm:

well, no real bad blood intended here, and Ron, Im sure you are to be commended for your services. I dont know you and dont intend any harm if it was taken. I dont like Cd's and things like them because Ive been around model T's for 40 years, and I would rather just try on my own and ask questions if need be. I just talked to you Ron the other day and was very appreciative. Here is an example, I bought that fun projects coil tester, but it looks like your telling me It might not be good for testing the coils completely? So did I waste my money?


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Leming on Sunday, May 20, 2012 - 08:12 pm:

Just to add, and again not to make anyone mad, but realize, we guys ask questions, and if you really go back and look at alot of the responses, we get pulled in alot of directions. Before I got my latest project finished I fell for a pump, Alternator, Thermostat, an aeremore whistle that doesnt work probably because the cutout for it leaks more exhaust then it puts thru the aeremore. on and on, so Im cautious. Since a couple have told me Rons the best, I trust him, but I still dont want the cd's - I bought the MTFCA booklets


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Jablonski on Sunday, May 20, 2012 - 09:05 pm:

Bud:

I could bet those points once removed & cleaned could be "worked" to the proper movement & tension...... if you want to save that particular point set.... and then calibrated on a HCCT.

The current production sets are about $7.00 last time I looked.


Bob J.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Jablonski on Sunday, May 20, 2012 - 09:07 pm:

Your picture shows the vibrator spring pushing up on the vibrator spring........ result.... no measurable clearance


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bud Holzschuh - Panama City, FL on Sunday, May 20, 2012 - 10:08 pm:

But when you attempt to pull down nothing moves as the rivet is tight


Top of pagePrevious messageNext messageBottom of page Link to this message  By Peter Borland. Bathurst. NSW. Australia. on Sunday, May 20, 2012 - 11:11 pm:

G'day,
I have successfully repaired points with the clamped rivet. Placed the bridge on the vice with just enough gap in the jaws to clear the point and tapped with a small hammer and a punch, the rivet. this stretched the rivet just enough to get the necessary movement of the upper point. Refitted onto the coil, tested and adjusted on the Strobo-Spark. I now have a happily working coil that was stuck in the too hard basket. Thanks to advice given by those in the know on this site, I have successfully recovered eight coils that I thought were stuffed.
To John Regan, Ron Patterson and the others that give advice and offer help to those of us who enjoy our hobby I personally wish to thank you all!

Peter


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bud Holzschuh - Panama City, FL on Monday, May 21, 2012 - 09:51 am:

Peter
Good idea! I will try it.
schuh


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