94 to 95 Air Filter

[Pat F.]

Re: 94 to 95 Air Filter

Tom, just as a follow up, in attempting to establish a date code for the air filters, yours is a good example.

You stated that the build date was October 94. If you look at the code of 4 J 20 D, it could possibly be decoded as 4-1994, J-October, 20-day of the Month and D for Day Shift. This seems to be the best we can do for date codes on these air filters. The earlier C4's did not have a date code on them that I could find. I have photos of original 90, 91 and 92's with no date codes. I do not have a photo of an original 93 or 94. The 95 and 96 air filters do have what appears to be a date code. Anyone out there with a photo of 93 or 94, or any other C4 air filter, please send it along.

Thanks to all that have contiributed to this issue.

[Ed N.]

Re: 94 to 95 Air Filter

Pat, I have a filter that the box indicates for 90-93 and it does contain a date code. The following is the inscription and date code" AC Rochester A1097C 3J19D

Filter.jpg

[Pat F.]

Re: 94 to 95 Air Filter

Ed, could you take a photo of the information on the side of the air filter?

Thanks

[Pat F.]

Re: 94 to 95 Air Filter

Ed, you may have an air filter that was made in 1993- 3-1993, J-October, 19th day of the month and D for Day Shift.

It is probably true when it was first put on the shelf it was marketed for 90-93 Corvette.

I am attaching photos of Original 1990-91 and 92 Air Filters. You can right away see the difference, even though they have the same Part Number and they have no date code.

Also notice that the 90-91 air filters have dimples along the side.

This why I am looking for an original air filter off a 93-94 Corvette to see when the change over occurred.

Thanks for you always good input.

[Ed N.]

Re: 94 to 95 Air Filter

Pat here are the pictures of the filter. So is this filter for 90 to 93 only, because it looks correct for 94 and 95.

90 to 93 Filter.jpgDSCN1138.jpgDSCN1139.jpg

[Pat F.]

Re: 94 to 95 Air Filter

Ed, I do not have a 92-93 or 90-91 Judging Manual but I know the early ones up until 1992 were labeled AC SPARKPLUG. I don't have the information on the 1993 air filter. Looking at the one you have it has the same type of brown/tan filter material as the 90-92 ones that I have photos of in my files. However it shows the identification of AC ROCHESTER. I do not have an example of a 1994 but the 94-96 Judging Manual on page 135 states "The 1994 and 1995 corvette air filter has AC ROCHESTER A1097C, stamped in black, along with a production code". "The early 1996 Corvette produced prior to January 1996, air filter may have AC ROCHESTER A1097C or AC DELCO A1097C". 1996 Corvette, with production January 1996 and later, air filter has AC DELCO A1097C.

The 1995 and 1996 air filters that I have photos of show a white filter material and not the brown/tan as shown in the 90-92's and yours.

Attached are photos of original 1995 and 1996 air filters nest to an early air filter.

The air filter you have may have been the start of the the cross over from AC SPARKPLUG to AC ROCHESTER in 1993.

Once again I do not have access to a 1993 Judging Manual, so if anyone out there does, please let us know what is said about the 92-93.

Pictures would be appreciated.

[Terry M.]

Re: 94 to 95 Air Filter

Just a word of warning for you C4 guys.
Do not confuse filters sold for SERVICE with the originally installed (OEM) units. When doing your research if at all possible stick to examples that were known to have been installed on the cars.

Those of us with earlier Corvettes have a lot of controversy because we have so few examples of OEM filters (all kinds of filters) we have resorted to specifying filters based on what was sold for SERVICE. There is no assurance that what was sold over the counter is the same in every way as what was originally installed, and in fact some believe that there was a deliberate difference so that when a car came in for warranty work GM personnel could tell if the filters had been changed for routine maintenance. You guys have an advantage in that there are likely to be more OEM examples available to you. Don't dilute your gene pool like we have.

[Ed N.]

Re: 94 to 95 Air Filter

Good advice Terry. The one I shared with Pat is a service replacement, but I have had many service replacements that were identical to the factory OEM filters.

[Ed N.]

Re: 94 to 95 Air Filter

Interesting Pat.

[Ed N.]

Re: 94 to 95 Air Filter

Ed, I do not have a 92-93 or 90-91 Judging Manual but I know the early ones up until 1992 were labeled AC SPARKPLUG. I don't have the information on the 1993 air filter. Looking at the one you have it has the same type of brown/tan filter material as the 90-92 ones that I have photos of in my files. However it shows the identification of AC ROCHESTER. I do not have an example of a 1994 but the 94-96 Judging Manual on page 135 states "The 1994 and 1995 corvette air filter has AC ROCHESTER A1097C, stamped in black, along with a production code". "The early 1996 Corvette produced prior to January 1996, air filter may have AC ROCHESTER A1097C or AC DELCO A1097C". 1996 Corvette, with production January 1996 and later, air filter has AC DELCO A1097C.


The 1995 and 1996 air filters that I have photos of show a white filter material and not the brown/tan as shown in the 90-92's and yours.

Attached are photos of original 1995 and 1996 air filters nest to an early air filter.

The air filter you have may have been the start of the the cross over from AC SPARKPLUG to AC ROCHESTER in 1993.

Once again I do not have access to a 1993 Judging Manual, so if anyone out there does, please let us know what is said about the 92-93.

Pictures would be appreciated.

Pat, did you get a chance at Kissimmee to take a picture of my OEM filter of my car?

[Pat F.]

Re: 94 to 95 Air Filter

Gentlemen, what Terry states is exactly how I describe my examples.

If I get a photo from a member who has had the Corvette from day one, I state that this is an original air filter and not a service replacement.

All the examples that I have shown as originals came from NCRS Members who were the original owners and kept the original air filter.

Thanks to both of you for your help and advice.

[Terry M.]

Re: 94 to 95 Air Filter

Good advice Terry. The one I shared with Pat is a service replacement, but I have had many service replacements that were identical to the factory OEM filters.

Ed,
I was remiss in not pointing out that I was not singling you out with my comment, and there may be valuable information to be gleaned from SERVICE filters. That has been the case for us, because for the most part it is all we have. The person(s) keeping the survey records just needs to be meticulous in identifying the source of the data. It sounds like Pat is doing that.

[Ed N.]

Re: 94 to 95 Air Filter

Terry, I did not take it that way. I am always open to advice and mentorship. Your input is always welcomed.

Thanks.

[Pat F.]

Re: 94 to 95 Air Filter

Ed, I did not get a photo of your air filter at Kissimmee. Where are going to be next?

[Ed N.]

Re: 94 to 95 Air Filter

God willing, Bowling Green. I'll see if I remove it a get a good picture of it.