MTFCA Forum

Trawling the old forum for items to add to the "After-market Items" section of the gallery (https://mtfca.com/phpBB3/app.php/gallery/album/75) I came across the two threads on Spark Plugs from 2017.

These showcase collections and related advertising and boxes of spark plugs and are well worth perusing. There are too many items in these to put in the gallery so I have just made the following link:

https://mtfca.com/phpBB3/app.php/gallery/image/2890

The thread links are in the description below the picture of Rich Eagle's Plug Collection Cabinet.

Cheers
Adrian

Great thing to collect. Check the Spark Plug Collectors of America for more info and a link to their Facebook page.
See you in Luray. Ill have a bunch for sale from an old collection I bought late last year.
Terry

Here is a new addition to my collection -found at Hershey

Terry is that name "Marwells"?

Yes. Had not heard of it before

There were Marswells lanterns and rifles. Perhaps it was the same company.

I believe that is a trademark for Marshall Wells Hardware , that was headquariered in Duluth, Minnesota.

That makes sense as a lot of hardware stores also sold auto parts in the teens and twenties. I have other plugs in my collection that were branded with hardware store logos. There were a number of early plug manufacturers who would privately brand them if enough were ordered.
Terry

Marshall-Wells were resellers from about 1892 or 3 to 1958.

Marswells was one of their tradenames as Jim has said, there is evidence that the plugs they sold were made by another firm but branded for Marshall-Wells per Terry's surmise. Various catalogues show them as being quite broad in terms of the wares they stocked, some detail is available here if you're interested:

https://americanhistory.si.edu/collecti ... AHTL_29773
http://albertmarshall.net/family-histor ... g-history/
http://www.davistownmuseum.org/bioMarshallwells.html

It's interesting to speculate just how many plugs were made for Model T's. I guess we know for sure there were ~64M, and if each T motor had at least one change of plugs that makes ~128M. In 1920 that was more than enough for every person in the U.S. to have one, today it's sufficient for every third person.

Did you ever seen this Firestone POLONIUM Toon

Polonium is highly toxic - but only if ingested. Its radioactivity is short lived (weeks I am told) and so it is unlikely any radioactivity remained when you bought the plug from the dealer, so there is certainly none left by now.

I wonder who came up with the idea that radioactivity would be helpful in getting a hotter spark?

The Polonium plugs work great. They are one of the old plugs that you can find a full set of and expect to get good service out of them. Polonium , has a very short half/life. They have no chance of being dangerous today. These plugs were from the time that "radiation" was considered a "good thing"

It was an advertising gimick. Consider the era the plugs were being marketed, when radiation was something new and mysterious - but powerful enough to win a war. So, it must make spark plugs more powerful, right? Actually, these are very common and were sold into the 1950s. The problem would be finding them in 1/2" pipe thread for the Model T.

Here are two recently acquired Model T related spark plug from my collection-
Terry

I have 4 NOS of those Firestone plugs in original box. I just can’t bring myself to installing them in my Model T !

Plugs do eventually wear out! I've been running Edison 14s in my 1924 since 2013. Last year I took them out to inspect them and the gaps had widened from the original 0.030 to 0.040. I re-gapped and reinstalled them.

I re-gapped and reinstalled them.

AHH! So they don't really wear out then - at least not in our life time..

Spark plug electrodes tend to become rounded due to spark erosion at the points where the spark occurs. This tends to increase the required firing voltage at any given gap setting. Most types of plug electrodes can be restored by careful filing. The erosion effect is most obvious with modern style plugs with a flat surface on the center electrode tip. As mileage accumulates, this flat surface tends to become rounded off. The same erosion will affect any type of spark plug. Excessive filing will affect heat range, and some styles of plug electrodes do not lend themselves to being filed.

These plugs were from the time that "radiation" was considered a "good thing"

Ever put your feet in one of these?

"I wonder who came up with the idea that radioactivity would be helpful in getting a hotter spark?"

The top salesman in the marketing department.

"The idea was that radioactive material would improve the electrical discharge between two electrodes. Polonium spark plugs were safer and less expensive than radium ones."
"The alpha particles emitted during its decay helped produce a stronger spark, claimed a 1929 patent issued to J.H. Dillon of the Firestone Tire & Rubber Co."
https://patents.google.com/patent/US1723422A/en

Ionizing radiation?