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Did all L78 and LS6 Chevelles come with A.I.R. smog pump regardless of plant origin, transmission type, etc.? If not, what would determine if it had to have the smog pump or not?
 

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Dale, ALL solid lifter cars came with smog pumps in 1970. L78, LS6, and LT1.
 

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Did all L78 and LS6 Chevelles come with A.I.R. smog pump regardless of plant origin, transmission type, etc.? If not, what would determine if it had to have the smog pump or not?

Dale,

I would have to agree with DB, but I have seen several 1970, LS-6's without those pumps. I asked the owners of those vehicles about the lack of that AIR pump and all I got was angry responses.

One guy with a red, 1970, LS-6, 454 was featured on the cover of an obscure car magazine about 15 years ago and had raced it at Englishtown Raceway Park, NJ (his info about the car and ET's were in an article in that magazine).

Sometime later, I saw his car there at one of the swap meets held there,(he had an unusual plate number) and questioned him about his missing AIR pump and regular exhaust manifolds, and he got pissed at me. Something about "Everyone says this is wrong and that's wrong.....well, this is the way the car was built......"
We just walked away......what an azzhole he was! :rolleyes:

I have to locate that magazine, if I still have it.


Respectfully.
John R.
 

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The smog pumps were one of the first things ripped off those cars and trashed. Anyone that says they had an LS6 without the A.I.R. pump either took it off and is pissed about how much they are worth now, didn't buy the car new, or is just ill-informed which usually makes them mad too :)
 

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I doubt any solid lifter V8 Chevies registered in the U.S. or Canada came new without the smog pump in '70, but I'm not a 1970 expert (I remember the 70's new at the dealership though).

Back then smog pump removal was not so much a "Day 2" modification, it was more of a "Day 1" modification.
 

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Makes you wonder why just asking about it would be such a touchy subject. There are probably quite a few National Show award winning cars out there without the factory delivered A.I.R. equipment that don't get questioned because the award givers don't know or care.

Back then smog pump removal was not so much a "Day 2" modification, it was more of a "Day 1" modification.
Got that right, just taking off the belt wasn't enough. Lots of Dorman and Edelmann brass plugs for the manifolds sold back then. I worked in several auto parts stores from late 69 to 73 or so and we kept those in stock as best we could. :D
 

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GM needed to help get those engines certified for production based on the smog laws of the time. The AIR system is how the engineers were able to get the engines to pass and be certifiable.
 

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What an absolutely silly concept for smog pollution control.

Pump fresh air into the exhaust to reduce percentage of measurable emmisions. ;)

Well done. :D
 

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What an absolutely silly concept for smog pollution control.

Pump fresh air into the exhaust to reduce percentage of measurable emmisions. ;)

Well done. :D
Actually, it's a well thought out concept that's used on present day cars. Today's cars use an electric pump that blows air into the exhaust to help the catalytic converter to light off quicker. The pump is controlled by the engine control management software. It's turned on and off when the ECM senses low coolant temperature or not enough catalyst function in the converter, based on the difference in voltage between the front and rear oxygen sensors.
Chevelles don't use converters, but the concept is still valid. Blowing air into the exhaust port when the spent gasses are still very hot will cause an oxidation reaction (burning) that will break the hydrocarbons into H2O and CO2, thus helping to eliminate smog. They weren't as effective as today's emission controls, but, when they were operating correctly, they did help.
Another interesting fact, you didn't lose much horsepower with the early systems. It only took about 3HP to drive the pump, and you could always bump the timing up a few degrees more than factory specs to gain that back.
BillL
 

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Actually, it's a well thought out concept that's used on present day cars. Today's cars use an electric pump that blows air into the exhaust to help the catalytic converter to light off quicker. The pump is controlled by the engine control management software. It's turned on and off when the ECM senses low coolant temperature or not enough catalyst function in the converter, based on the difference in voltage between the front and rear oxygen sensors.
Chevelles don't use converters, but the concept is still valid. Blowing air into the exhaust port when the spent gasses are still very hot will cause an oxidation reaction (burning) that will break the hydrocarbons into H2O and CO2, thus helping to eliminate smog. They weren't as effective as today's emission controls, but, when they were operating correctly, they did help.
Another interesting fact, you didn't lose much horsepower with the early systems. It only took about 3HP to drive the pump, and you could always bump the timing up a few degrees more than factory specs to gain that back.
BillL
Bill,

Thanks for that useful info. :beers:


Respectfully,
John R.
 
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