MTFCA Forum

What is the most common reason for all of the coils to buzz properly when the timer roller makes contact except one, which buzzes constantly? It has never done that before. Jim Patrick

The wire between the coil box and the timer is grounded someplace between. What the timer does is to ground each coil at the time when it should buzz, but if the wire is grounded, it will buzz constantly.
Norm

Thank you Norm. I’ll check that out tomorrow. Jim Patrick

I had an older reproduction roller timer cause a coil to buzz constantly.

One of the metal contact shoes inside the timer had shorted to the timer case.

Makes great sense Ed. I’ll check that out too. I watched the coils and determined it was the the #2 cylinder so it shouldn’t be too difficult to track down the source. I just needed to know what to look for and your guys have really helped. Jim Patrick

I don't offhand recall which cylinder it is? But one of the timer contacts is quite close to one of the bolts that holds the front cover down to the front of the pan/crankcase. That silly thing has been known to be fine for years, and then suddenly without warning settle or shift just right and ground out that one cylinder!
That bolt is supposed to be installed from the top down, rather than the usual bottom up to avoid shorting the timer contact. But a lot of people without the proper shop manual (including me when I began!) put them in bottom up.

If I recall correctly, 1926/'27 coil boxes run the wires a bit close to the metal parts of the box. They have been known to shift and short out quite often if care isn't taken to route the wires clear of the metal.

Good luck my friend!

You need to fix that---NOW!. I had the same thing happen and it resulted in a "coil boil" What a mess. A lot of smoke and melted tar. My car still stinks. bobt

I had the same thing happen and it resulted in a "coil boil" What a mess. A lot of smoke and melted tar. My car still stinks. bobt

Your coils were not likely adjusted properly for the correct, equal and consistent firing time. If they were, I doubt you would have suffered a coil Melt down based on my experience. Here's why:

https://mtfca.com/phpBB3/viewtopic.php? ... us#p157543

Note that I am not suggesting the problem does not need to be fixed, it definitively does. Also not suggesting it's OK to let coils buzz continuously for 10 minutes. It is not good practice and should be avoided.

I had this happen on my 1911 once and i can say from experience that you should never ever attempt to crank an engine by hand with a coil that is always buzzing. It will fire early and mule kick you every single time. Dangerous stuff. In my case the clearance for the timer rod is very close on an early engine with a spring loaded fan. These early cars with two piece timers used a timer rod that did not have the high arch at the timer end like the later ones did. They can very easily short against the engine timing cover when the spark lever is at full retard. The quick fix is to slip some insulation or shrink wrap around the spot in the rod that is making contact with the timing cover until you can remove the radiator and really work with the shape of the rod in detail. Another common mistake is having engine crankcase bolts installed the wrong direction which puts the bolt ends up where the timer terminals hit them when the timer is rotated. The nuts should be below the pan in these locations to keep them away from the timer.

Each coil is only on about 12 % of the time or they would all be hot all the time, do a melt down, and not function as Henry Ford had planned.

Anytime one coil is operating continously regardless of timer position can be caused by several things as indicated in several responces to the original post. But I can tell you this, it can be very dangerous fire hazard and you had bettered get to the bottom of the cause immediately!
What hapens is shown in the attached photo and worse yet the points get jamed closed by the hot tar boiling out of the primary winding core hole on top of the coil wood top. Ron Patterson