Author Topic: '69 ZL2 350 Cowl Induction air cleaner  (Read 9605 times)

rjprice

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'69 ZL2 350 Cowl Induction air cleaner
« on: October 25, 2021, 05:18:00 PM »
I have a '69 L48 with what looks to be an original ZL2 air cleaner.  The problem is the snorkel is missing.  Are these date coded?  Could not find any data on this.  My engine is a T0409HB 300hp auto. 

Should it have the flapper gizmo on the snorkel or just be smooth?
Does anyone sell the snorkel by itself?

Thanks.

169INDY

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #1 on: October 25, 2021, 05:33:00 PM »
"Should it have the flapper gizmo on the snorkel or just be smooth?"
Yes. (* Thermac Air Valve) was part of the Emissions for the 350-300/TH350 Auto combination.)
"Does anyone sell the snorkel by itself?"
Not sure.

I have often wondered "IF" the snorkel portion was common to other air cleaners and could one source and Harvest a snorkel from say a closed Std air cleaner.
Jim
68 SS/RS L35 Th-400 LOS
69 Pace Car L48 Th-350 LOS
68 Z28 M21 LOS

william

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #2 on: October 25, 2021, 05:50:44 PM »
Had the same situation many years ago. Removed a snorkel w/Thermactor from a 2bbl air cleaner, had it tack welded. Indetectable.
Learning more and more about less and less...

rjprice

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #3 on: October 25, 2021, 06:21:47 PM »
Had the same situation many years ago. Removed a snorkel w/Thermactor from a 2bbl air cleaner, had it tack welded. Indetectable.

Exactly the answer I was looking for!

So before I re-snorkel, the air cleaner base is not date coded, right? 
Is the Thermactor Air valve itself date coded?

Thanks,

Roger

cook_dw

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #4 on: October 25, 2021, 10:56:06 PM »
Had the same situation many years ago. Removed a snorkel w/Thermactor from a 2bbl air cleaner, had it tack welded. Indetectable.

Yep we (father and I) did it on a pace car back in the early 2000’s..

z28z11

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #5 on: October 26, 2021, 05:06:08 AM »
I've done this more than several times, made "reproduction" Therm A/C cleaners for this application (L48 auto w/mandated ZL2 air cleaners like Pace Cars). You'll need a donor 2 or 4 bbl period air cleaner (use a 2 bbl if you don't want to sacrifice a 4 bbl), hopefully complete with the green 4bbl vacuum valve and the hose clips on the bottom of the air cleaner - you'll need these to make it cosmetically correct amd functional, too. I carefully remove the snorkel without damaging the flange, drill out the spot welds holding the clip, then spot weld the snorkel to the cleaner body after spot welding the clip in place (only way to spot weld the clip is to reach through the empty snorkel opening with the tongs and spot it twice to position it and keep it in place). Do it this way and, as William says, it's undetectable.

No, the base is not date coded (I have an NOS ZL2 cleaner in the box to base this on). Remember, early ZL2 cleaners had a flat bottom where the filter sits, a raised rib version was a second design and the first design to be reproduced. Flat bottom cans are in reproduction if you want to use one -

ZL2 manual or automatic air cleaners all used painted lids, not chrome -

Regards,
Steve
1968 Z28 M21/U17 BRG/W 1967 Chevy ll Nova SS 
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

rjprice

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #6 on: October 26, 2021, 01:15:11 PM »
I've done this more than several times, made "reproduction" Therm A/C cleaners for this application (L48 auto w/mandated ZL2 air cleaners like Pace Cars). You'll need a donor 2 or 4 bbl period air cleaner (use a 2 bbl if you don't want to sacrifice a 4 bbl), hopefully complete with the green 4bbl vacuum valve and the hose clips on the bottom of the air cleaner - you'll need these to make it cosmetically correct amd functional, too. I carefully remove the snorkel without damaging the flange, drill out the spot welds holding the clip, then spot weld the snorkel to the cleaner body after spot welding the clip in place (only way to spot weld the clip is to reach through the empty snorkel opening with the tongs and spot it twice to position it and keep it in place). Do it this way and, as William says, it's undetectable.

No, the base is not date coded (I have an NOS ZL2 cleaner in the box to base this on). Remember, early ZL2 cleaners had a flat bottom where the filter sits, a raised rib version was a second design and the first design to be reproduced. Flat bottom cans are in reproduction if you want to use one -

ZL2 manual or automatic air cleaners all used painted lids, not chrome -

Regards,
Steve
Very helpful.  My base has the ridge.  Any idea when the ridged base began? I have a early April engine and 4/14 production date for the car. Don't think mine is a repro as it has all the vacuum clips and fittings.  It may be from a later car or a maybe a chevelle.

z28z11

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #7 on: October 26, 2021, 07:58:07 PM »
There are several discussions and threads in the forum about this - I'll search through here when I have a moment. There are examples noted of the flat bottom up through about May if I remember correctly, but don't quote that yet.

Wonder why the snout is missing on yours ? There are generally 4 spot welds that hold it in place, some repops I've seen have 6-8 small ones. Share a pic of the mounting area if you think about - just curious as to why someone would remove it.

Regards,
Steve

Try this one, there are a couple of others in the archives:

 http://www.camaros.org/forum/index.php?topic=14154.msg123981#msg123981
1968 Z28 M21/U17 BRG/W 1967 Chevy ll Nova SS 
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

69Z28-RS

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #8 on: October 26, 2021, 11:49:28 PM »
With the snout removed, the air cleaner will get MORE air in situations when the cowl flap is closed.
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69 Corvette, '60 Corvette, '72 Corvette
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z28z11

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #9 on: October 27, 2021, 03:12:17 AM »
Pic of Warren Malkin's SCCA Z - evidently (according to the post) there was a GM part number for the ZL2 with no snorkle, it would add air flow when the flap was sealed. I just don't see it for street applications - I was wondering if fatigue or rust on the spot welds may have been the culprit. Running one for a long time without the heat riser tube could add to that (the spot welds I've seen over the years can be hit or miss. A pic will show if it was deliberate.

Regards,
Steve
1968 Z28 M21/U17 BRG/W 1967 Chevy ll Nova SS 
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

rjprice

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #10 on: October 27, 2021, 03:37:32 PM »
Took some pics of my air cleaner. I see 4 snorkle spot welds. Ridged, 90 degree tube, and what looks like forming wrinkles as others have called them.  70 Chevelle?

rjprice

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #11 on: October 27, 2021, 04:06:55 PM »
A few more pictures. Getting better at resizing.

rich69rs

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #12 on: October 27, 2021, 07:07:07 PM »
- evidently (according to the post) there was a GM part number for the ZL2 with no snorkle….

Would that have been emission legal since removing the snorkel also removed the Thermactor?

Richard
Richard Thomas
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69Z28-RS

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #13 on: October 27, 2021, 07:55:05 PM »
- evidently (according to the post) there was a GM part number for the ZL2 with no snorkle….

Would that have been emission legal since removing the snorkel also removed the Thermactor?

Manual shift cars didn't have the thermactor... so no reason it wouldn't have been legal.   Although I'd love to see the evidence referenced that there was a PN for a ZL2 a/c without the snout... Steve?   Can you provide the reference you cited?

Richard
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

rjprice

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Re: '69 ZL2 350 Cowl Induction air cleaner
« Reply #14 on: October 27, 2021, 09:02:57 PM »
So as has been suggested, I can add a snorkel to this base for around $50 looking at ebay.  Should I repair this one, even though it is not the right base for an early April car or should I look for another correct base or repro? 

What would you do?