Correct Spark Plugs?

[Joe Gopan]

The 10 packs do not need to be sealed, it is the individual spark plug that needs to be preserved. There are 10 to a box and a Jeep only uses 4, there may be instances where only one spark plug is needed to replace a bad one. The Firestones used to come packed in crates that I remember to be approximately 24"-30" square with a tarpaper like barrier lining the crate. It is a possibility that Firestone may have made more spare sparkplugs than the OEM suppliers. 70 years have passed since the war, plenty of time for civilian consumers to use up much of the surplus examples.

[lucakiki]

After 9 pages, one might legitimately wonder if anything changed in the available information on correct spark plugs for use in a WWII jeep, be it for judging purposes or for one own's pride in owning the correct plugs.

I wish someone would volounteer and use up a little more bandwidth for a concise recap.
Brand and time frame for MB and GPW.

[Chuck Lutz]

Willys:
1) up to 1/13/42 the QM-2
2) @ 1/13/42 a "CHANGE" to AN-7
3) @ MB 170xxx (August 1942?) the Champion J-9 is "optional"

( FILO/LIFO may have caused overlaps)

Ford:
1) QM-2
2) No info as of yet on Ford making a "CHANGE" to the AN-7
3) No info as of yet on Ford also making the Champion J-9 "optional"

Firestone F-40 is a gov't replacement (not Ford/Willys)

[Mark Tombleson]

I want to bring this back up as we have new guys wanting to know what the correct spark plugs are!

[Henk]

According to Delmar Roos in Lloyd White's book Volume 4 page 91, spark plug designation was changed from QMC-2 to AN-7 on 8-20-43 (start in production).

[Myers]

Any new information on the GPW spark plug timeline?

[Joe Gopan]

I have sold dozens of surplus Firestone F-40 Sparkplugs for 4 Cyl Military and CJ application over the decades. We started off with an approximate 30" square crate of them.

[Joe Gopan]

I have sold dozens of surplus Firestone F-40 Sparkplugs for 4 Cyl Military and CJ application over the decades. We started off with an approximate 30" square crate of them.

[Farrell Fox]

[Post Deleted By Author]

[Joe Gopan]

The Spark Plug has a very basic purpose which is to provide an Air Gap for a spark to jump.

Did you know that the "AC" Spark Plug brand name stands for Albert Champion. And you all have heard of Champion Spark Plugs.

[Nikko]

Hi Chuck

This spark plug info is great for al of us.
Enny more info on the spark plugs i am thinking of the
CHAMPION J 9 inn Blue boxes if i remember right

Cheers From The Cold North
Nikko

[conrod6]

A little more information on the Firestone F-40 'Polonium' plugs - according to 'anything radioactive' website (sorry can't give a link) they actually were radioactive using Polonium 210 - this had " a half life of 138 days so after 3 years virtually all the radioactivity had decayed and turned into a non radioactive isotope of lead"
So they should be safe after 80 years then !

Barrie

[fernando mendes]

[JAB]

Thanks Fernando! I never understood hot/cold sparkplugs until that picture!

[BERLIN RED]

On an odd side note. The military f-40s come in boxes of 10. Could that imply that it was 2 sets for 2 jeeps counting the for a spare?