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Firestone Spark Plugs...Radioactive

Posted: Mon Oct 07, 2019 4:34 pm
by Ruxstel24
I have 6 of these FS “Polonium” plugs.
Trying to find what they fit and found info about the ground electrode being radioactive !! :shock:
Anyone know what they fit ?
Too small for Model A...5/8” thread, box says T-40-F, but plug is marked M-100.
The 6 I have are NIB old stock, like to sell them, but any knowledge prior would be appreciated.

Re: Firestone Spark Plugs...Radioactive

Posted: Mon Oct 07, 2019 6:00 pm
by Scott_Conger
https://www.orau.org/ptp/collection/con ... kplugs.htm
and

from Wikipedia: Polonium spark plugs were marketed by Firestone from 1940 to 1953. While the amount of radiation from the plugs was minuscule and not a threat to the consumer, the benefits of such plugs quickly diminished after approximately a month because of polonium's short half-life and because buildup on the conductors would block the radiation that improved engine performance. (The premise behind the polonium spark plug, as well as Alfred Matthew Hubbard's prototype radium plug that preceded it, was that the radiation would improve ionization of the fuel in the cylinder and thus allow the motor to fire more quickly and efficiently.)[70

Re: Firestone Spark Plugs...Radioactive

Posted: Mon Oct 07, 2019 10:45 pm
by Ruxstel24
Thanks Scott, that’s interesting stuff.
I found also, some had a pink porcelain insulator.
Nice collector piece.
Still nothing to cross an application.
I have numerous new smaller MOPAR plugs that these were with, and 6 of these...maybe a Dodge 6cyl ??
Anyone have any ideas where to find a cross reference or application ?

Re: Firestone Spark Plugs...Radioactive

Posted: Tue Oct 08, 2019 1:31 am
by Mark Gregush
Are you sure they are not 18 mm? Which would be early Ford V8

Re: Firestone Spark Plugs...Radioactive

Posted: Tue Oct 08, 2019 1:26 pm
by Rich Eagle
These pink ones were in a model A I bought in 1962. (7/8" threads) #S-120-CF. The white one is a M-100 with a different base.
Polonetc.jpg

Re: Firestone Spark Plugs...Radioactive

Posted: Tue Oct 08, 2019 3:27 pm
by Ruxstel24
The pink ones are cool. 8-)
I believe these are 5/8” like the box says.
Not sure what the 10MM refers to, maybe the hole size at the bottom...looks about the size.

I will try looking at the Champion stuff and maybe find a match to the threads and an application ? :?: