Embossed AC212CW Air Filter Element Age

[67since67]

That's a great filter Tim!!

[TimG]

Bill, we will see how it does in two weeks. It will be on a small block, so no one will will even look twice at the car ��

[jeffschevelle]

Originally Posted by bergy

It’s actually not a big job to change the embossing on those molds. The pattern shop probably had updated versions along with older versions on the shelf. It always amazes me that people think that there are hard cut off dates for cosmetic changes. The updated mold could be damaged in production - supervisor calls the pattern shop for a mold replacement - and the old mold replaces the damaged mold. Iron patterns were the same way. Cosmetic changes could be run interchangeably. Engineering changes were more disciplined.

I don't disagree at all with that in general. But a couple observations:

Regarding the change from the large outlined AC A212CW embossing, to the small AC SPARK PLUG A212CW embossing, my first question is WHY did they make the change? Two plausible reasons come to mind -

(1) The older style is almost impossible to see / read if you don't put the light on it the right way and make some effort to find it (shows up much better in pics than in person), while the later style is much more obvious and easy to see / read. Seems like a good reason to change it.

And (2) apparently someone in company brass must have decided that the actual name of the company "AC Spark Plug" should be on their filters rather than just an "AC" logo. Tinkering with how a company's name appears on the company's products is usually not left to the plant workers at or near the bottom of the management chain, and comes from a directive "on high".

If either or both of those possible reasons are why the change was made in the first place, then I think it very unlikely that they would have reverted back to the old style after the changeover was completed. Some overlap during the changeover process is certainly possible, even likely. But once all plants / lines had changed, I think going back most likely did not happen on this particular item.

Regarding the changes to the shape of the top and bottom and presence of (or absence of) the indentions (which create a little more stiffness in the filter body), that seems more like a change with an engineering reason, versus just a "cosmetic" decision. So again, once all plants / lines had changed, I think going back later to the flat top without the rim indentions most likely did not happen.

Just my thoughts and conclusions. Feel free to disagree!

[dvss1]

Here's another example that I thought was for the 69 and 70 model years. This has the white lettering and a very small and faint embossing.

[jeffschevelle]

Are there any box print dates on the flaps of the box?

The 8 indentions around the outside edges (top and bottom, with none around the inside edge of the bottom), should make that a later filter design than the one Jason posted. (Subject to the overlap discussion above).

I believe yours was made after they switched the square-holed mesh filters from a diagonal orientation to the horizontal / vertical orientation, because all the horizontal / vertical Square Mesh filters I have ever seen have the 8 indentions top and bottom, while I have never seen a Diagonal Mesh with those indentions on top (and they have 16 on the bottom). Again, the judging manual says that change happened late August or Sept of 1969.