Embossed AC212CW Air Filter Element Age

[SBR]

When did they make the filter with the small raised letters without the silk screen? I have seen a few but of them over the years. I am fortunate to have a virtually flawless one that's exactly like Bills on my 67 Corvette. Those original AC filter elements are really cool.

[jeffschevelle]

Originally Posted by SBR

When did they make the filter with the small raised letters without the silk screen? I have seen a few but of them over the years.

That would have been for a brief period during the 68 model year, after the embossing changed, but before the silk screen was added.

Large embossed font lasted until AT LEAST 8/1967.

The earliest box date I have for a silk screened filter (which has the small embossed letters and silk screen together) is 3/9/1968.

So the small font without silk screen should fall some time between those dates. (Of course, the window could be shorter than that, but should not be longer than that.)

[SBR]

Originally Posted by jeffschevelle

That would have been for a brief period during the 68 model year, after the embossing changed, but before the silk screen was added.

Large embossed font lasted until AT LEAST 8/1967.

The earliest box date I have for a silk screened filter (which has the small embossed letters and silk screen together) is 3/9/1968.

So the small font without silk screen should fall some time between those dates. (Of course, the window could be shorter than that, but should not be longer than that.)

Great info, thank you! I was told by someone on the corvette forum that the small raised lettered version came out sometime in 66. That really never made sense to me that there would be two different versions of the same filter made at the same time. I thought the only way that would be possible is if there were multiple manufacturers of those AC filters???

[napa68]

Originally Posted by SBR

I was told by someone on the corvette forum that the small raised lettered version came out sometime in 66.

There can be some real genius's over there

That's why I like it here so much more!

[SuperNovaSS]

First off,

Jeff,

I can not express my gratitude and your commitment to the details of this hobby. Your knowledge never ceases to amaze me and I doubt I am speaking for only myself.

Thank you everyone for the replies.

After initially not receiving replies to this thread, I posted this filter up on EBay here:

https://www.ebay.com/itm/376607210634


I offered the filter element to others here for $2500 and will honor that for other paid members. I know it is a crazy chunk of change for a used element but it is one of those devil in the details items. More detailed pictures can be seen in the ebay listing.


Thanks,


Jason

[TimG]

That's all great data.

[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.

[scuncio]

For sure. Today that would require a “TWO” (temporary work order) which is considerably faster than a formal engineering change request.

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.

[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.