Missing Mag Post Spike

[MarkS]

First, my '15 starts and runs on mag.

I live in a hilly area and decided to add a mag post outside oiler. I took off the mag post today for the first time, and expected to see a spring-loaded spike. Instead, I found no spike, but a spring that extended down and makes contact with what looks like a large blob of solder. In researching mag post oilers, I have seen lots of photos of spring-loaded mag post spikes, but nothing like this.

Is it something aftermarket, something homemade, or ??? Still learning a lot about this car.

[RajoRacer]

The point is A.W.O.L. !!!

[Wayne Sheldon]

And your point is? Missing?

It looks like a more standard spring, likely someone's idea of a replacement/repair. I would suggest removing the nut off the top, and carefully pressing the bolt and spring out just to see what else is inside. As long as the connections between the spring and the bolt are reliable enough? That could be a decent enough repair. I suppose the broad base of the spring could possibly short against something? However without one sitting in front of me at the moment, I can't recall anything on the field coil frame close enough to likely make a shorting contact.

[JTT3]

If it has a brass upper it may be very early. The first of this type did not have the spike but soon there after they added one.

[DanTreace]

The earlier mag posts used coil spring around center conical nose to contact the solder pad on the magneto coil ring. These have brass, then later steel uppers. Your nose cone is missing, likely in the crankcase now.

Last design until the ‘26-‘27 Improved T, was moulded composite upper and contact became just a coil spring with a pig tail that embedded into the solder pad.

[MarkS]

Looking at it a little closer, it looks like the upper housing and the base are two separate pieces, not magnetic and sort of looks and acts like Bakelite when I touch it with a small file.

Thanks for the photos.

[JTT3]

Some further information for your review. Depending on the material of the mag post you could have the earliest of the early mag post, if not then yes the slug is awol. Best John

[Will_Vanderburg]

I’ve got one of these in my stash

[MarkS]

I cleaned up the mag post in question, and it looks quite similar to the 11-25-1908 to 12-7-1911 described in the reference document JTT3 was kind enough to post. The base flange is definitely some kind of fiber composite, and the upper sleeve is brass. The spring may very well be phosphor bronze as it has that sort of coloring and is non-magnetic. Where it differs from the description is that the sleeve is crimped in 4 places at the bottom (the reference says 2 places) and the Fillister-head screws are 1/2” long (the reference says 3/8”).

Thanks for the info!

[DanTreace]

Mark

Believe your mag post is later version, as it's thick fiber base and has the bevel around the top of the base. The fiber can age and these parts can separate.


Here is the what your post is like:

Another brass type with the nose of steel.

The final design about 1917, of the mag post made the entire upper in the fiber like material, which later years is Fordite, or the steering wheel material of later Ts. These have a metal shield or base for the attachment screws, and the metal base helps to prevent warping of the fiber material. The other one is the '26-'27 which is a pipe thread version.

[MarkS]

Thanks Dan for the additional info. Based on what you posted, the bevel and the use of imitation leather for the gasket puts the mag post squarely in the time window for my engine manufacture. I did find a thin black gasket (very brittle).

Thanks everyone again!

[DanTreace]

Mark

Here is the complete story, just less photos to show the changes over the years on magneto posts. Page clip from Encyclopedia on Club Homepage, under Resources, Old version.

https://www.mtfca.com/encyclo/I-O.htm#mag2




Later style post on a '25, with intermittent engine miss running on mag. Typical reason. Band lining fluff gets tanged with oil saturated with metallic engine wear and combines to short out the mag pickup spring against the iron coil ring, shorting out to ground the AC current being generated.

Best reason to use inspection cover oil screen accessory,that catches this stuff before it collects on the magneto pickup.

[MarkS]

Thanks again Dan. Very informative!

My T education continues.