Running on Battery

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Mark Osterman
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Running on Battery

Post by Mark Osterman » Mon Jun 08, 2020 12:17 pm

I generally start and then run my car on magneto. In the past month or so I was showing people how it could both start and run on either, but I noticed it was not running well enough to drive on battery.

I cleaned the plugs, the timer and adjusted the carburetor. Still it wouldn’t run smoothly on battery. Then I had the second cylinder cut out. So the only thing left was the coils. I started by removing the coil from the dead cylinder. The points were pitted concave on one side and convex on the other. I dressed them with a stone and reassembled the coil. Then gave the coil a few turns on my hand crank coil tester. Looked perfect. I put it in the coil box and started the car and the dead cylinder was revived.

Did the same to the other three coils and .. bingo .. runs great on both battery and magneto. It has better acceleration and smooth stronger running. I guess I forgot all about the coils in the past two years. Brent had rebuilt them and I had never had professionally rebuilt coils before owning this car. Now checking the coils and points is back on my list of spring check ups.

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Re: Running on Battery

Post by RustyFords » Mon Jun 08, 2020 12:54 pm

Brent rebuilt my coils as well.

Not too long ago, the car started running roughly (like it was running on three cylinders) so I limped it home, located the dead cylinder then swapped coils which helped verify that it was a malfunctioning coil. Upon inspection, I found that one of the mounting posts had slighty backed off allowing the points to become misaligned. I fixed it and that solved the problem.

Like you noted, the coils require periodic inspection, cleaning, etc. Mine will get a thorough going over before the Texas T Party in a few months.

I went ahead and bought two more professionally rebuilt coils that I keep in my tool box. That'll allow me to quickly fix a coil problem on the road and fix the errant coil later at my convenience.
1924 Touring

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Re: Running on Battery

Post by HPetrino » Mon Jun 08, 2020 1:15 pm

When I was a kid my grandfather was using what's now my TT on his ranch. The ol' truck and his Cat 2 Ton were his main implements. The truck was there when he bought the ranch in 1946. It never left the place until he retired in 1963 and it was hauled to the new house.

Every year in the spring before fruit season started, after it had sat neglected all winter, he would pull out each coil one at a time. look it over, blow on it, look it over again, then put it back. Each spark plug was removed one at a time, a little emery cloth applied, blow on it, then return it to its rightful place. Then he'd check the tires, although I don't know why as he had no compressor to add air if needed. Next, and last, he'd check the oil. He'd add oil if it needed it but in the entire 17 years he used that truck it was never changed. Oilers and grease cups simply did not exist.

That darn old truck ran reliably (on battery or magneto) the whole time he used it. It always started right up and ran just fine. However, by the time I got it the damage was done. I could write a book on how bushings look after decades of hard use and neglect. :lol:

Les Schubert
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Re: Running on Battery

Post by Les Schubert » Mon Jun 08, 2020 1:33 pm

Reading the postings made me think about my 27 roadster that I have owned and driven for 45 years. About 40 years ago I rebuilt and installed “automotive condensers”(probably the Ford version from a auto parts store). I installed NOS points then. And they just WORK!! I typically hand crank start it on mag. Generally I leave the key on mag and turn off the gas with the throttle on fast idle to stop it. Yes occasionally I will use the starter.
One thing I like about starting on mag using the crank is it is a lot safer as the chance of getting a “kick back “ is a lot less, as the mag has only 3 timing positions. Slightly retarded for starting, about 15 degrees advanced for climbing hills, and about 30 degrees advance for highway cruise

Norman Kling
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Re: Running on Battery

Post by Norman Kling » Mon Jun 08, 2020 4:25 pm

The points will last longer when you run on magneto because the current alternates on mag which will cause metal transfer to go in both directions and you get one spark. When you run on battery, your current will constantly move in one direction and will buzz continuously especially if you leave the ignition on without the engine running. You will also get a higher voltage on magneto especially when you run at higher speeds.

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Re: Running on Battery

Post by JohnH » Mon Jun 08, 2020 6:39 pm

40,000km driving on my set of points always run on battery, and there's plenty left in them. I thus don't consider wear an issue running on DC. Having said that, I've rebuilt coils for others with badly pitted points, but that's because they were using 12V or had set the coils for too high current.

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