Corvette A.I.R. Pump?????

[DTOM]

I replaced the belts (alternator, air cond, and water pump) on my 73' this weekend. I took a closer look at the pulleys and have been trying to figure out (actually, for a while now) why there is a third groove on the water pump pulley not being used.

Out of curiosity, I looked through pictures of 73 engines and saw the A.I.R. pump on some of them (center right on the front of the block / next to the air conditioner) but not all of them.

I pulled out my restoration guide and it's a little confusing. In the opening paragraphs of the section on the A.I.R. pump it says that not all 73s had them. At the end of the same section, it says all 73s did have them.

I do have headers though and re-reading the restoration guide, the pump hooks into the exhaust manifolds. So in the end, this may be a stupid question I just answered myself. But hey, we never learn if we don't ask.

The car runs great and I don't have a problem with my vacuum system, but I am still curious

1) If the car should have an A.I.R. pump?

2) What advantage or disadvantage not having one causes?

Any thoughts or experience here is appreciated.

[6880 Mike]

All 73s had AIR.

Some states require emissions testing and require stock emissions systems to be in place.

If you have to pass emissions testing, you might need the original AIR.

[DTOM]

6880, thanks.

I am good on the emissions. At least until the Army moves me back to California.

I guess I am trying to figure out what the AIR pump did and would it even work with headers?

What I have found shows it hooking into either the manifold or exhaust. So I am guessing the answer is no.

Looking a pictures of 73 engines it is a mix of those that have it and those that don't.

[Texdentist]

Originally Posted by DTOM

6880, thanks.

I am good on the emissions. At least until the Army moves me back to California.

I guess I am trying to figure out what the AIR pump did and would it even work with headers?

What I have found shows it hooking into either the manifold or exhaust. So I am guessing the answer is no.

Looking a pictures of 73 engines it is a mix of those that have it and those that don't.

The AIR pump was an early attempt at emissions reduction. It simply injected air right at the exhaust port to cause total combustion to be more complete. My '83 El Camino has it and I can't take it off because I have to get annual inspections, and even though I don't have to pass emissions tests any more (they only go back 24 years), all emissions equipment must be present and hooked up. It's a real PITA if you want headers because if you live in an inspection state, you have to get headers with the connectors over the ports. If you don't have to have it for inspections, you don't need the pump.

[DTOM]

Tex, thanks. That helps.