Packard Forum Index » Post-War (1946-54)

I have a 1950 8 sedan with the 288 CID inline 8 engine. I put in new spark plugs in two years ago, and upon inspection today the central electrode on five of the plugs are simply "gone."

The plugs were correctly gapped when I put them in. I don't know if the auto parts store gave me the right plugs, they were model Autolite 308

My question is, what spark plugs have any of you used with success, and would recommend?

Many thanks!

I favor the Autolite 308, I have been using them for years in Packards from the 30s thru 1954 with excellent results.

I would not consider two year old plugs as "new" regardless of brand. They just don't last as well in the old points low compression environment as the modern high energy exotic metal ones.
If the other 3 were "like new" then you know 5 places to focus your search.

They just don't last as well in the old points low compression environment as the modern high energy exotic metal ones.

Certainly true, but you should still expect to get 8,000 to 10,000 miles from a traditional spark plug in a Packard or similar vintage engine.

My 1946-1950 service manual only has engine specs up to the 22nd series, and my 1950 is a 23rd series. According to the engine specs in the book, a 22nd series with the 288 CID inline 8 has a spark plug gap setting of .025"-.030"

I hate to assume, but it would be the same gap for the 23rd series with the 288? Thanks!

23rd series engines were direct continuations of their 22nd series counterparts, same specs. So same plug gap. That gap was pretty much the standard for L-head engines, whether GM, Ford, Chrysler, and others.

You did remember to use the metal gasket/sealing washer? Important not only for sealing the compression but also for heat transfer.

If that's the washer/gasket that came with the plug, then yes, I used it.

Probably just a bad batch of plugs from the factory. Replace the plugs and try again. Was any of the porcelane around the ceentre eletrode broken or chipped or otherwise damaged???? If so then most likely the plugs were handled rruff before installation (dropped on floor etc) caausing the damage.

I have a extremely hi heat motorcycle engine application here that i have rode for over 40 years every year. The spaark plugs will easily run 15K to 20K miles. I think i haveonly replaced them 3 times in 40 years and some 50K miles.

You either got a bad batch of plugs or thee plugs were dropped and carelessly handdled at the factory or store or at sometime before installation.