Don't worry, these vintage Firestone spark plugs may be over 70 years old but they are no longer radioactive, sadly do not glow in the dark and, in case you were wondering, are perfectly safe and legal to own and handle*.

They are safe because the trace amounts of radioactive Polonium 210 used in the electrodes had a short 'half life' of just 138 days, which means that barely three years after they were made virtually all of the radioactivity had decayed and turned into a non-radioactive isotope of lead. For the record it was all a bit of a con, based on some questionable science that suggested it might improve engine performance and fuel consumption. Apparently it didn't...

These genuinely historic mid 20th Century Atomic Age relics are supported on custom designed 3D printed stands, mounted on solid wooden bases and can be easily removed, should you so desire, and even used for their intended purpose, assuming you have a suitable vintage vehicle to put it in.

We have a very limited number of these very unusual Polonium spark plugs available, most of them sourced from now defunct Stateside auto parts stores. They were manufactured in the USA by Firestone and come from batches produced in the early to mid 1940s. Each plug comes with its original cardboard box, plus a scanned copy of the original wax paper  information leaflet/wrapperPlease note that most of the cardboard boxes are in pretty good condition but a few show some signs of damage; we'll always do our best to include the best available for as long as stocks last.

We currently have three types on offer including the brand new M-60 'SUPERDOME' version. But we'll begin with the first two, which have part numbers S-140 CL and S-120-CF.  They are both the same size but the latter - see left - is particularly rare with a highly unusual pink-coloured porcelain insulator. Both types have been mounted inside large 120 x 70mm, tough borosilicate glass domes, sitting atop a 90 x 15mm turned and polished, solid wood base. The dome and the spark plug are easily removeable for dusting or closer inspection.




NEW!  M-60 'SUPERDOME'

If you think the first two were impressive, take a look at our imposing new M-60 SUPERDOME. The glass dome* measures a whopping 150 x 100mm, with a solid Oak base (120 x 20mm), finished in luxury Osmo oil and a high-quality wax polish finish (it's worth buying just for the smell...). This time, the spark plug is accompanied inside the dome by its original box (also mounted on a custom 3D printed stand) and a small frame bearing a copy of the wax paper wrapping on the front (see above), and on the back two miniature reproductions of original press and outdoor advertising for Firestone Polonium spark plugs, dating from the 1940s. 


Whilst these historic spark plugs have been in storage for several decades they are in virtually 'as-new' condition. One or two had signs of light surface corrosion but this has been removed. Nevertheless, some may have minor blemishes, but this reflects their age and does not detract from the overall appearance. 
Our stocks Polonium spark plugs are now low and becoming increasingly difficult to find so don't miss out on this rare opportunity to own a highly unusual piece of automotive history and WW II memorabilia, with macabre contemporary overtones...

*SOME VERY IMPORTANT SAFETY STUFF!

Needless to say, but we'll say it anyway, broken glass can be really dangerous, so please treat these items with care. Keep them well away from all children (and clumsy adults) as well as pets and anyone or anything else that might drop, knock or damage them.


The domes on the SL-120 and SL-140 are not fixed in place, to allow easy access. The larger, heavier and therefore more easily damaged M-60 dome is fixed to the base to help protect it, and its contents. If you prefer we can supply it unsealed but we don't recommended it, unless you promise to be super cautious.. 


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Vintage Firestone 'Radioactive' Spark Plugs - Prices from £40.99 inc UK p&p. UK SALES ONLY

  • Product Code: Firestone Spark Plug
  • Availability: In Stock
  • £0.00


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