Identifying a GM cowl induction air cleaner from a reproduction

[z28z11]

X2 on Rick -

This repro is the closest I have seen to being correct - but the part number mentioned should be 6485891. The 6485235 cleaner is listed for '70 454, switches back to 6485891 for the '71 Chevelle in my catalog.

http://secure.classichq.com/COWL-AIR-CLEANER-ASSEMBLY-FLAT-BOTTOM-P139C100.aspx

I wouldn't have a problem using the CHQ myself -

Regards,
Steve

[abiddle]

Thanks for the pics Steve. Those pics match what I have exactly, mines just a little dirtier...Does your box have a date on it?

Here's what I think, based on these pictures and everything I've read. Just to put it all out there, and see if this can lead to a consensus of sorts.

Earlier ZL2 air cleaners had no ridge and had a 90deg vent tube
Later ZL2 air cleaners (> Aug 69) have the ridge and the 90deg vent tube, this same design was used for the 70 Chevelle SS
At some point the design changed to a 2x45deg vent tube, which is found on the GM parts purchased (NOS and service parts)

Maybe the 2x45deg vent tube may not have been found on an assembly line part, but the design was changed to accommodate double pumper carbs for a more generic service part?

Andy

[abiddle]

And back to canadair's question. Attached is the picture of this reproduction bottom. Compare this to the picture above by Steve. The forming wrinkles in an original are very obvious and not duplicated by the reproduction part. With this information, you should have no problem identifying an original GM part vs a reproduction.

Andy

[X33RS]

CHQ part looks good.  Do they make the spacers as well?

[z28z11]

Thanks for the pics Steve. Those pics match what I have exactly, mines just a little dirtier...Does your box have a date on it?

"July 10" but the year is marked out. No box markings other than the label (could be on the bottom flap, I only ever opened one end).

I bought this cleaner sometime in the mid-80's. The "4 spot" flame arrestor was included with the cleaner when I received it. I have no doubt it's a post - '69 manufacture. Ridged bottom or not, I'm still happy to use it on my X77 (which was a flat hood car to begin with). I have the original flat hood and air cleaner in storage -

My NOS 6423907 open element cleaner is dated '95 on the label - one of the last ones in GM inventory when I bought it in '96-97 for the '68 Z.

Regards,
Steve 

[69Z28-RS]

Thanks for the pics Steve. Those pics match what I have exactly, mines just a little dirtier...Does your box have a date on it?

Here's what I think, based on these pictures and everything I've read. Just to put it all out there, and see if this can lead to a consensus of sorts.

Earlier ZL2 air cleaners had no ridge and had a 90deg vent tube
Later ZL2 air cleaners (> Aug 69) have the ridge and the 90deg vent tube, this same design was used for the 70 Chevelle SS
At some point the design changed to a 2x45deg vent tube, which is found on the GM parts purchased (NOS and service parts)

Maybe the 2x45deg vent tube may not have been found on an assembly line part, but the design was changed to accommodate double pumper carbs for a more generic service part?
Andy

That's fairly accurate, except that there wasn't an August changeover to the ridged bottom; probably '70 Chevelles built in August '69 DID have the ridged bottom, BUT.. my original 18Sept1969 '69 Camaro Z28 has the flat bottom cowl air cleaner with the 90 deg bend tube.    So either that particular fact is wrong, OR there was a lengthy changeover period for that newer designed part...

[Bryan302]

X33RS, yes CHQ has the ext. ring and the seal flange available separately.  Click on the link of CHQ that Steve posted, then click air cleaner and intake, just above and left of air cleaner picture. 

Bryan

[X33RS]

Thanks Bryan, I found it thanks to the link you mentioned.

[abiddle]

Hi Gary - I read this from Jerry, and others have reported the ridged bottom as original in their late 69 camaros. It may not have been a full changeover, maybe it was a sharing of parts for awhile?

Hello Jerry
I have a 69 Z28 (August build) that has a grooved base on the air cleaner which I have been told is incorrect. My research indicates that the correct base had a flat bottom until May of 1969 but have found no information on what the base looked like after May. I would like to correct this issue but want to make sure that I replace it with the correct piece. You assistance would be appreciated.
Thanks
Ervin

Ervin, the change over to the “grooved bottom” was Sept of 1969. Here is an original ZL-2 air cleaner bottom with flat bottom. All ZL-2 hood cars built from Jan 1969 through August 1969 received this air cleaner base.

[69Z28-RS]

Hi Gary - I read this from Jerry, and others have reported the ridged bottom as original in their late 69 camaros. It may not have been a full changeover, maybe it was a sharing of parts for awhile?

Hello Jerry
I have a 69 Z28 (August build) that has a grooved base on the air cleaner which I have been told is incorrect. My research indicates that the correct base had a flat bottom until May of 1969 but have found no information on what the base looked like after May. I would like to correct this issue but want to make sure that I replace it with the correct piece. You assistance would be appreciated.
Thanks
Ervin

Ervin, the change over to the “grooved bottom” was Sept of 1969. Here is an original ZL-2 air cleaner bottom with flat bottom. All ZL-2 hood cars built from Jan 1969 through August 1969 received this air cleaner base.

Yes, I've read that also.. ..  There are a number of things that might be accepted by some as 'fact' that there's great doubt about re 'late Camaros (and Corvettes for that matter).  In both cases, Camaros and Corvettes, the 1969 model year ran several months longer (Dec '69 or so), and during that abnormal production period some things changed and others didn't.  For example, my August Camaro and my late July Corvette each came with 'dripper' valve covers, and I've discovered many others which also have the '70 drippers, although JM and his books say '69's didn't have drippers!   Bryon Miller here is doing a research task on differentials, and it's been identified that around August of '69, the differentials began being stamped as '1970 models' (with a C in front of the normal stamping)..  so one has to be careful with absolutes, especially wrt vehicles, and most especially during 'unplanned' abnormal production periods, as Chevrolet certainly didn't begin the 1969 model year with intention of producing '69 Camaros and Corvettes for 16-18 months!

[abiddle]

I don't have any skin in the debate, if we can call it a debate. And it certainly doesn't make sense to put a line in the sand (e.g. Sept 69) on the changeover to the ribbed bottom. The purpose of the rib is structural, so I imagine it was simply a design change that was made for the new Chevelle part. Since the 70 SS Chevelle cowl induction part is interchangeable with the 69 Camaro ZL2 part, it makes sense the vendor would not continue making flat bottom parts and ribbed parts at the same time. Logically, the assembly line would use a part until they mixed with the new parts and eventually the flat bottom air cleaners would not be found on the late 69 camaros once the flats were used.

Maybe we could say an August through end of year air cleaner on a camaro is correct if flat bottomed OR ribbed. I think it could be either. Can we live without a rule?

[abiddle]

Does anyone have any evidence of a factory assembly line ZL2 air cleaner with the two 45s in the vent tube?

The two 45s have been found on the GM replacement part 6485891 and the reproductions (except the CHQ reproduction is designed to match the earlier design flat bottom and 90 vent tube).

[69Z28-RS]

I don't have any skin in the debate, if we can call it a debate. And it certainly doesn't make sense to put a line in the sand (e.g. Sept 69) on the changeover to the ribbed bottom. The purpose of the rib is structural, so I imagine it was simply a design change that was made for the new Chevelle part. Since the 70 SS Chevelle cowl induction part is interchangeable with the 69 Camaro ZL2 part, it makes sense the vendor would not continue making flat bottom parts and ribbed parts at the same time. Logically, the assembly line would use a part until they mixed with the new parts and eventually the flat bottom air cleaners would not be found on the late 69 camaros once the flats were used.

Maybe we could say an August through end of year air cleaner on a camaro is correct if flat bottomed OR ribbed. I think it could be either. Can we live without a rule?

I think one has to keep an 'open mind' about various possibilities that can and do occur in a production manufacturing operation.  I didn't build cars, but I did engineering for a computer graphics company and was responsible for some of the products, and it was not unusual for manufacturing to call me re an order they were trying to get out to tell me about a 'problem', so I would truck over to our manufacturing building, observe the problem and come up with a solution that didn't conflict with law, our internal practices, or our marketing information.  Our biggest concern near the end of months and quarters are shipping out to order!  (the systems I was dealing with were $200K-250K products, so it had a significant impact on monthly/quarterly production, which sometimes seemed to be the major thing upper management was concerned with..

[L78 steve]

I would like to know what the factory did with the COPO ZL1's with the DP carb. The flat bottom 90 Degree elbow would interfere with the secondary pump arm.

[abiddle]

What I wouldn't give to just have a few more pictures of this engine!!!