Did all 69Z28 cowl induction breathers have a flat bottom ?

[z28z11]

Outlined in the attached pic, but I'll get a better contrast tomorrow in daylight. You can at least see the depressions in the red circles; what function they served is debateable (maybe to help mount the screen onto the pipe ?).

Regards,
Steve

[Northernforce]

Thanks everyone for your input-the  4 dimple flame arrestors also had "GM" stamped on them-(although it wwas hard to read)I have a couple NOS ones -boxes dated 1982 -if anyone is looking for one!
Dave

[z28z11]

Steve,

Can you take a photo of the full bottom from the bottom?  As a comparison to the flat bottom?
PS.  What did you mean by '4 spot' flame arrester?   first time I've heard that term....

Gary,

   Here's your pics. One thing I also noticed when I took a good close look at the cleaner, my NOS 6485891 is a lot worse in finish and appearance than the one I just finished and put on line to sell, one of my L48 "resto creations". I was worried about paint finish and a couple of small blems: it looks much better than my NOS example - I don't feel so bad about letting this one go. Take a glance at it when you have a minute -

Regards,
Steve

http://www.ebay.com/itm/171124384456?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

[z28z11]

Pics -

[69Z28-RS]

Thanks Steve,  That should give everyone a good comparison between 'flat bottom' and 'seamed bottom'.
Question:  is the seam on yours welded all the way around?  or ?

[z28z11]

Gary,

   No seams that I can determine - the stamping was apparently done in one draw, and then progressively formed in secondary operations including the snout (and hose clamps on auto air cleaners) welding. There are not any other welded areas on these that I have ever been able to find. Draw die evidence includes the "ribs" you see around the coil clearance recess area - vertical lines as a result of deformation (wrinkling) in that operation - most cleaners usually have a pattern all the way around the can where the metal is deformed during the drawing. I have to base all of this on the second designs; the only flat bottom ZL2 cleaner I have examined was during a quick inspection of an X33, March car, P-O-P, that was being shipped to Montana during an owner's move. Looked like your cleaner, exactly. Wish I had been able to take pics -

Regards,
Steve

[69Z28-RS]

Yes, mine was a single piece of metal, stamped out, and has all the typical deformations from such an operation, but the 'seam' on the bottom of yours I thought was a joint?  a welded joint?   If not, then what is it?

[z28z11]

It is a stamped detail that fits the bottom of the element. It's not welded or folded, just stepped. The recess in the top/bottom of the element fits right in it to seal it. Can is smooth on the reverse side - it would have been a piece of work to finish it that way if it was welded (took me more than several hours to smooth, prime and finish details on the L48 cleaner I just finished for eBay - I doubt the Delco division would have ever put that much intensive labor into one).

Regards,
Steve

[BULLITT65]

thanks for all the detail, and pictures. So, since they are reproducing the stepped version can you tell them apart?

[z28z11]

They look very similar. Pretty obvious that they modeled the repros from the second design - the details are there, the metal thickness is close, but the paint on most is just a little too glossy. I haven't been able to get close enough to one of the repro flat bottom cleaners to judge them, but the pics look spot on. At least someone finally put the notches on the air snorkels to really get the details more correct.

I will use my NOS 6485891 cleaner when I restore my X77 - I've had it too long to think about sending it down the pike or replacing it with a repro - 

Regards,
Steve