Did Dealers remove SMOG?

[Chevy454]

So, would an auto car be different? From reading the above, it seems everyone agrees the manual cars got the AIR pumps, but we are "iffy" on the auto cars...?

[L72COPO]

I believe the article went on to say that all solid lifter cars, manual and automatic, had the AIR system. Can't recall the "rule" for California built and sold cars.
My Camaro is a M-21.
Sorry for not including this in my original reply.
Thanks
Don Stowers

[Rowdy Rat]

A gentleman that I know had his Corvette at a local show back in March and brought much of the paper documentation for the car along with him. It seems that a previous owner had made inquiries to GM of Canada (it was originally a Canadian delivered L-88) about the possibility that it was delivered without the A.I.R. equipment. He received paperwork back from GM regarding Canadian specific options, in particular, an option called KD1 which allowed the buyer to delete the A.I.R. equipment (subject to local laws). It was listed as available for all passenger cars with the exception of Corvette.

I have no idea if this was a "paper option" or if people actually ordered it, but it is certainly worth researching.

Regards,

Stan Falenski

[Chevy454]

I was looking through our copy of "The COPO Connection", in the back of the book, where it shows the AMA specs for the ZL-1 & the L-72, it has a heading for the smog pump, but it also show an asterisk (*). When you refer to the footnote, it says "manual trans cars only".

So, is this something that was incorrectly printed due to lead time or...?

[Kurt S]

2 relevant posts from John Z from the CRG site:

Factory smog calibration in those days was simpler on automatics due to the relatively constant and progressive engine load conditions; with a manual, engine loads (and carb metering variations) varied widely, and A.I.R. was required to overcome the rich mixture "spikes" during acceleration and manual gear-changing. Same issue at idle - automatic cars were under an even, constant engine load, but manual cars weren't - that's why A.I.R. cars had retarded base timing, ported spark, and later advance curves - created a rich idle condition, which ensured there was enough unburned fuel in the exhaust gases at idle to "keep the afterburner lit" in the exhaust manifolds with the injected air to keep tailpipe HC numbers down at idle (this also created more heat and higher coolant temperatures at idle). That rich idle condition is why Gary had such a battle trying to pass the HC portion of the Delaware emissions test without the A.I.R. system in place and operating to burn off the excess hydrocarbons in the exhaust manifolds. Later on, catalytic converters simplified calibration somewhat, and even later computer-controlled closed-loop port fuel injection systems coupled with catalytic converters solved it entirely (at VERY high cost).

(The above) post applied to the SB issue; the big-block Camaros were a separate issue, and Jerry is quite correct that ALL big-block '69 Camaros (L34/35/78/89) had A.I.R. systems, regardless of transmission application. EPA emission certification was done not only by powertrain, but by carline application, vehicle weight, aero drag, and coast-down horsepower testing, which created many variables. Every different situation required full EPA certification, including 50,000-mile durability testing, and Chevrolet apparently decided that rather than go to the time and expense of developing and certifying eight different low-volume Camaro big-block combinations, they'd go with only four, that they knew would pass and certify with A.I.R. For the high-volume passenger cars, however (Impala/Caprice), which were built in Nine assembly plants at 7,500 per day (vs. only one plant of Camaros when you factor out the Firebirds at Norwood), it made sense to certify high-volume passenger car combinations as much as possible without the added per-unit cost of the A.I.R. system, so many full-size Impala/Caprice big-block applications were developed and certified WITHOUT the A.I.R. system. I had a brand-new '69 Caprice 2-door hardtop with the 427/THM400 combination, and it didn't have A.I.R. either. Full-size cars and Camaros were totally different certification situations.

[JoeC]

Welcome back Kurt...that's a great John Z post.

[Kurt S]

He's great! He is a nice guy, knows a lot, AND can communicate that info.