AIR pump...all cars by 69?
I was under the impression that all 1969 Corvettes, including those for export, had AIR systems. On the thread about 1972 LT-1 weights, it has been suggested that some Corvettes did not have the AIR system by 72. I also have some big block manifolds without AIR provisions. Can anyone shed light on this subject?
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Re: AIR pump...all cars by 69?
You are correct, but 1969 is not 1972, nor is it 1970. One has to consider the installed emissions equipment year by year and engine by engine since the "rules" changed with each year and engine.
In 1970-1972 only those engines with solid lifters got AIR emissions equipment EXCEPT (there always is an exception it seems) those 1972 base engine equipped Corvettes destined for California delivery. Those also got AIR.
Enough light Mike?Terry -
Re: AIR pump...all cars by 69?
Mike,
The matrix of which cars and which did not have AIR or other emission control devices in the C3 era is quite complex. I think Joe L has mentioned many examples of car specifications that met certification without AIR. I remember judging a '78 L48 w/auto that did not have it and was surprised.Comment
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Re: AIR pump...all cars by 69?
Terry's on the money here! When it comes to A.I.R., you can't make a sweeping generalization as to which cars had it vs. those that didn't. You have to go year by year and look up the facts on an engine configuration specific basis...Comment
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Re: AIR pump...all cars by 69?
Also remember that for each car, there was a 49 state configuration and then another configuration for California. Generally, but not 100% the California configuration for 1969 would be the 49 state configuration for the following year, but only on an identical engine package. Small changes could drive a recertification and equipment changes.Bill Clupper #618Comment
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Re: AIR pump...all cars by 69?
My 68 327/350 L79 has AIR and 70 350/300 does not have AIR from the factory.Comment
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Re: AIR pump...all cars by 69?
AIR is added to burn unburned hydrocarbons in the exhaust system, Longer camshaft duration in the 350hp version would make it much more likely a candidate for AIR than the 300 hp version.Bill Clupper #618Comment
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Re: AIR pump...all cars by 69?
All------
While ALL 1968-69 Corvettes were equipped with AIR, that was not the case for all other Chevrolet cars of those model years. In general, 1968-69 Chevrolet cars used AIR if also equipped with manual transmission. However, if equipped with automatic transmission, they generally did not use AIR. Some folks get confused on this point and assume that this general rule also applies to 1968-69 Corvettes. It does NOT.In Appreciation of John HinckleyComment
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Re: AIR pump...all cars by 69?
The applied engine tuning may also determine if the AIR system is needed. For example, the 69 L46 did have AIR, but the 70 L46 did not. However, in 70 the TCS system was used, and the purpose was to reduce the ignition timing in certain conditions. Other tuning changes may also have been made (for example, the carb setup).Comment
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Re: AIR pump...all cars by 69?
Correct, TCS was much more "cost effective" than an AIR pump. The late 60's thru 1974 (prior to Cat converters) were a constant battle between the California driven laws (which the 49 states followed a year later) and the engineers who were assigned to meet the standards at minimal possible cost.Bill Clupper #618Comment
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Re: AIR pump...all cars by 69?
GM had the Controlled Combustion System (CCS) as well as AIR. CCS leaned the A/F and retarded the spark to reduce unburned HC and CO.
I pulled the cats off one of my cars, and used the CCS strategy to get it to pass an emissions test. Passed the test...didn't drive very well.Comment
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