The Ford Barn - View Single Post - Spark Plugs C-4 Take Apart With Green # and letters

barnstuf · 06-23-2019, 03:40 PM

In 1932 Ford introduced a V8 engine and the C-4 spark plug was the official spark plug made for that engine and recommended by Ford.. The 3X was the official Ford Motor Company spark plug for both the Model A and Model B.

In 1933 the Ford V8 engine for that year and subsequent years did not use the C-4 and they would not fit.

Now suppose you operate a spark plug company who had thought Ford V8 would use the C 4 for a long time, and had produced large quantities of C 4 to meet the supposed demand.

Very likely what happened is that those C 4 plugs in the warehouse will fit the Model A and the Model B, and while not Ford recommended plug the heat range on them is close enough for satisfactory service so advertise them for aftermarket use on the A and the B. This is my guess as to the reason they were promoted as the aftermarket replacement spark plug.

06-23-2019, 03:40 PM	#5
barnstuf Senior Member Join Date: May 2010 Location: Cape Cod MA Posts: 2,840	Re: Spark Plugs C-4 Take Apart With Green # and letters In 1932 Ford introduced a V8 engine and the C-4 spark plug was the official spark plug made for that engine and recommended by Ford.. The 3X was the official Ford Motor Company spark plug for both the Model A and Model B. In 1933 the Ford V8 engine for that year and subsequent years did not use the C-4 and they would not fit. Now suppose you operate a spark plug company who had thought Ford V8 would use the C 4 for a long time, and had produced large quantities of C 4 to meet the supposed demand. Very likely what happened is that those C 4 plugs in the warehouse will fit the Model A and the Model B, and while not Ford recommended plug the heat range on them is close enough for satisfactory service so advertise them for aftermarket use on the A and the B. This is my guess as to the reason they were promoted as the aftermarket replacement spark plug.