Still on the learing curve in low gear...

In the previous thread, there was mention of 'getting the coils checked'. Would one of you guys mind telling mre more about that? What would that involve? And, why would that be important?

Thanks!

Michael
16 touring

Michael - The coils are the electrical heart of your ignition system. Coils that are not properly rebuilt and adjusted will not perform well and your car will run poorly. I would venture to say that all of the old original coils that have the original capacitors in them need to be rebuilt. The old capacitors leak badly and will cause other problems in the coil. The MTFCA offers a 3 disc cd set that will explain coils in great detail. But simply said your coils should have new capacitors and points and be adjusted on a hand cranked coil tester for proper output.

"What would that involve" It involves verifying that the condensors are good and the points are adjusted properly. This takes special equipment such as a hand cranked coil tester or one of the new "Strobo Spark" coil testers. That is the only way to tell if the points are working correctly.

"Why would that be important" If your points are not set correctly (tension on cushion spring)they will double spark. This means instead of one real good spark you will get two weaker ones. Those weaker sparks will not be 180 degrees of crankshaft from each other but will vary by a few degrees which causes engine vibration and loss of power.

You can't set the points with a feeler gauge and call it good. The lower point will also require bending so the coil draws the correct current. The current controls the strength of the magnetic field that pulls the points apart and the cushion spring and limit rivet control the dwell time.

If your coils are set correctly and you have a working mag and good timer and coil box your T will run super.

What Mike said. I was typing while he posted.

Michael,
Christmas is now a little over 6 months away. If you search this Forum for threads on coils, it will keep you occupied until then.
But to summarise, the Model T is a quirky car, and its most quirky feature is its ignition system. This has three main sub-systems, the so-called 'magneto' which is really a flywheel-mounted alternator producing up to 30v AC, the four trembler coils which produce the very high voltage needed to make sparks, and the timer, which is like a distributor, but it switches the coils on and off so they produce sparks at the right time. The coils have primary and secondary windings (it's really a transformer) which are very reliable, a capacitor which, if original, probably leaks by now and should be changed, and some contact points on bendy springs which vibrate and provide the control. These eventually burn or become maladjusted. More commonly they are maladjusted by people who have neither the tools nor the understanding to get them right.
You can make a simple holder for a coil with contacts which allow you to feed it (with a 6v or 12v battery) and observe and listen to the sparks. This will get you an engine which runs quite well, if you do things right. But most Forum contributors will say that to get the best possible running, you need to check out the coil in either a Hand Cranked Coil Tester (HCCT) which is a Model T magneto in an iron frame with a handle to turn and a ring of sparks to observe, or a 'Strobo-Spark' which is a clever (and much lighter) modern piece of electronics which does almost the same job. With one of these, you can see individual sparks. Both tools are expensive, the HCCT more so, being a rare antique. Or you can employ someone with one of these tools - Ron 'The Coilman' Patterson being a prime example.

That's a summary.

One quick check you can do. With the top of the coil box removed, set the engine at a slightly fast idle. Then press lightly on the lower contacts (the circular discs) of cylinders 2 and 3 at the same time to stop the coils buzzing. This should leave cylinders 1 and 4 still running smoothly. Release 2 and 3, and then stop numbers 1 and 4. This should leave cylinders 2 and 3 running smoothly. This will give an instant result as to whether all four cylinders and coils are working. If one cyclinder isn't working, swap coils around and see if the fault moves. If it does, you have a faulty coil; if not, it's something else - the timer, valves, plug etc.
Keep fingers away from the lower side contacts - these are the outputs to the plugs. Everything else is low voltage.

Model T coils will not run very good if at all unless the coils are properly setup. When properly setup on a Hand Cranked Coil Tester (HCCT) or Strobo-Spark tester (CT-1) they will then deliver one and only on hot spark event for each pulse from the T magneto and thus run synchronously as perfectly timed by the magneto with the timer acting only as a "selector" as to which magneto pulse will be used for the ignition event. The difference in the way the T runs with properly setup coils is night/day versus having just coils that seem to "spark" OK. The worst way to set them up is using a "buzz box" type of coil tester that has only a meter and a set of points where the spark jumps. Use of buzz box types of testers to adjust a T coil generally results in rather poor performance. Often someone near you has an HCCT or you can even build your own if you are handy and have access to a few T parts like flywheel, magnets, and magneto coil.

Ron Patterson has written some excellent articles that explain the T coil/magneto/timer ignition operation as it was designed to work. Those articles can be found at my company web site document library at www.funprojects.com They are free and recommended reading to all T owners.

More great information!!! Thanks you all so much for the input.

For other on the learning curve...you should check out the youtube video that demonstrates the Strobo-spark. It's a commercial, but very good info..."I think". http://www.youtube.com/watch?v=7JvN9PIPOWc

So now, are there similar type tester for the mags and timer?

Best,

Michael

Michael
FunProjects also makes the St Louis Magneto tester. It is the finest magneto tester I have ever used.
I know of no commercially available timer tester.
If you are concerned about your coils working correctly I can loan you four rebuilt units to help diagnose the problems. They have beat up wood boxes, but work great. The only obligation would be for you to pay the shipping both ways are return them within two weeks.
Ron the Coilman

Hi Ron,

What a kind gesture! I am just about to order the coil tester and Mag tester from John. I will let you know how things test out and will plan on sending the coils to youfor a possible rebuild if necessary.

The testers will add a new sparkle to my tool box!

Best..and thanks again,

Michael

Michael
Be sure to get the MTFCA three disc CD videos Mike recommended. I prepared the technical content, everything I know about coil rebuilding is therein and I get no compensation from CD sales.
Ron the Coilman

And be sure to buy your coil replacement capacitors at Lang's Old Car Parts of FunProjects. There are still some Model T parts suppliers selling the wrong part.
Ron the Coilman

Have 'em done Mike. Or really get into it and replace the caps yourself. As Ron posted: get the caps from Lang's. I followed his suggestions and did my own caps then a friend (Bob. J.) set them up on his HCCT unit. I can't impress you deeply enough with the amazing change in the engine's power and runing over all ranges with properly set up coils. I resisted for YEARS, using only a buzz box set up. After all what difference could it make? they buzz OK don't they? Man what a jerk I was. I was actually on the verge of doing a valve job to improve performance when I finally listened to Ron and others on the Forum and I only did it then because it was easier than doing the valves! I'm convinced. I'm picking up a T Touring tomorrow. The caps are already on order.

Setting the points is not as easy as it sounds. I am constantly amazed how quickly and easily Ron does the job. I find it hardest to get flat contact across the points even with washers under the posts, although sometimes getting the right tension is difficult. I'd hate to admit I've ruined some points in the process. Maybe if I had done a few thousand, it'd be easy.

Richard,
Maybe Ron can comment but if you are fussing about getting "flat contact" across the points you are fighting a loosing battle. There is no way to get an exact full contact so that the points make an electrical contact over the full surface every time they make contact. I try to get the single point of contact on the point surface off the edge of the points, other then that I don't think there is much you can do.

When I resurface (grind and hone) the points face I put a slight crown in the surface so that the contact is not right on the edge of the points. I don't know how much of a crown new points have but I would guess that they are not dead flat.

Jim

All...Am I wrong in my thinking; If the coils test out ok on the Strobo-spark, I should leabe well enough alone?

Also...yes, thanks, I'll order the videos.

Best,

Michael

Jim
Sometimes it takes considerable fiddling to get the point contact geometry correct, but it can be done. You may have to remove and reinstall the points several times adjusting the shims accordingly to get the point contacts to mate correctly.
Michael
If it ain't broke don't try to fix it. Until you get some experience you will only make the coil work worse by fooling around with it.
Ron the Coilman.

Yes, If they test out OK, I'd leave them alone.

It is my understanding that the Strobospark will test the condition of the condenser. That is a plus over the HCCT. However, if those are original Ford coils that have never been rebuilt, I'll bet the condensers leak. Also, if anyone has messed with the points since the last time those coils were on a HCCT, you can bet they are either double sparking, missing sparks, and/or pulling the incorrect current. None of which is nearly as hard to fix (Or at least not as time consuming) as replacing the condenser. That is the worst part of a coil rebuild. The point adjustment is the fun part.

For those that have messed up a good set of new points - don't feel bad. I have done hundreds of coils (new) that have perfectly flat tops and need absolutely NO shimming but still on occasion I have had a set of points that I finally gave up on and installed a new set in their place. It happens. Brass tends to work harden and the top bridge if bent too many times will get very hard and that makes the adjustments even harder to "hit" on the correct spot so the main trick is to try and get it right on the first try at bending but regardless of how good you think you are at it - on occasion there is just a set of points that will not tweek to correct position regardless of how many times you went to church last month. I have gotten way better at it over the years but it still happens to the best of us.