AC 45 Plug Design

[Anthony F.]

Guys I need a little help remembering here.

I seem to remember that there was an article in the Restorer some time back about the differences in how the AC Spark Plug was made or looked through the years. I have found some NOS AC 45 Fire Ring plugs and would like to determine when they where used.

If any body has an idea of when the article was written or by whom, please let me know. I have included a Scanned picture (not to clear) of the type I am talking about.


Thank You

Tony
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[William C.]

Re: AC 45 Plug Design

Late 50's-early 60's based on the box (sometimes a date on one of the flaps) and the green rings. I don't beleive the green was on the rings prior to about '58 based on a batch of NOS plugs I had at one time...

[Jack H.]

Add-on

Early plugs had no color bands and NO circular ribs on the porclean upper body through approximately 1957.

Then, 1957L to approximately 1959, there were circular ribs on the porclean but no color bands.

Starting 59L-60, the circular ribs had four thin equally sized green color bands. Late plugs (I can't recall the date of introduction, but something like mid-70's sounds right) had four green color bands with the top/upper band being thicker/wider than the three below below it...

[Anthony F.]

[Robert Jorjorian]

Re: AC 45 Plug Design

Tony,
yes your understanding of the box flap date is correct.
In your case, the number 4 is the month the box was made,Bob

[Roy B.]

Re: AC 45 Plug Design

If you have or find the original plugs they last longer by cleaning them , I still have the original plugs in my 55 after 75K miles.

[Anthony F.]

Re: AC 45 Plug Design

Roy,

When I was younger, much younger, and worked in a Texaco Station we used to clean plug a lot for people rather than replacing them. It was a good business decision for the station and the customer. In other words, I know where you are coming from. Thanks for the comment, it is something everyone can do and I still have a cleaner in my home garage.

Tony
#9436