A.I.R. pump question

[arcticvette]

just bought my '80 vette and when I got it the belt was removed from the a.i.r pump. I've never owned a car with this system so don't know exactly what it is doing other than trying to improve emmisions. would this have been done to increase hp or possibly a malfunction with the pump? if it's for hp would it not be possible to just remove the whole deal and save weight and clean up engine bay? also the flexible aluminum hose from air cleaner to heat sheild on manifold is missing on my car, don't know what it does either or if it is beneficial not to have this part. I guess my question would be am I hurting anything be it mechanical or performance by not having these things hooked up? car was also missing air intake duct and duct hoses to air cleaner but have a line on them and intend to get them back in place soon.
Mike

[steelblue75]

You can ditch the A.I.R. pump, as for the heat shield, my 75 doesn't have one. By the way, Welcome

[SLOVETTE]

My '81 has most of the smog equipment removed by Bubba and friends before I got it. The AC condenser is hanging loose from the alum tubing. I may "lighten" the car a little more and get the AC belt off the pulley.
No spare tire carrier, so I figure I'm 150 lbs lighter than a "stock" '81.
I have picked up a few horsepower and the lighter car makes dring more fun.
Unless you need to meet emissions, unbolt the AIR.
Welcome!

[JohnZ]

The A.I.R. pump has virtually no effect on performance; when operating, it uses less than 1/10th of a horsepower. Its only downside is that it could seize at very high mileage. The emission components that kill performance are the carb calibration, retarded ignition timing, and a retarded advance curve, not the A.I.R. pump. If you remove it, hang onto it - that pump and bracket could be worth a good hunk of change to someone who lives in an area that requires emission testing and whose car is missing the system.

[arcticvette]

If you remove it, hang onto it - that pump and bracket could be worth a good hunk of change to someone who lives in an area that requires emission testing and whose car is missing the system.



well if it's not doing anything anyway it might as well come out, I may end up doing something crazy with my motor anyway. Maybe I can sell it to the 'Governator'

what about the carb air heat hose as it is missing should I be looking for a replacement for that? what does it do?

Mike

[paulie]

Originally Posted by arcticvette

what about the carb air heat hose as it is missing should I be looking for a replacement for that? what does it do?

Mike

All that hose does is lead to the THERMAC on the snorkel of your air cleaner.There is a little flap inside of the snorkel and it closes to let hot air from the manifold into your engine when it's cold and after your engine reaches operating temperature, the THERMAC flap opens to let cool air in. I don't think you have to have it if you plan on making your engine crazy like you said. I don't think iit makes a big difference if you have it or not. If you need a second opinion some of the others will be happy to help you. Hope this helps some.

[arcticvette]

thanks for the insight

[Mr. Chuck]

I belive that the flex duct serves bring heated air in to the carb, especially in climates where they have winter cold; mixes with cold outside air to warm the intake air coming into the carb. The control valve in the intake air housing regulates the amount of warm air entering carb. Engine warm up in cold weather in much slower without the flex duct and has negative effect on engine performance and gas milage. I was born and raised in PA and always made sure the heat riser system was working correctly when winter time arrived.
I also agree that if you ever move to where you need smog, then you will need the A. I. R. pump, especially in California, where they just repealed the no smog needed after car is 25 yrs old law. Smog is now required until you move out of state or scrap the car, unless to register it non-service.

One more opinion to consider.

[jdp6000]

I would put the flex hose back on if you are using the stock air cleaner. Its a generic part and only costs about 5 bucks. Try Canadian tire....

As for the air pump. You probably don't need it unless you have an O2 sensor. Look for a stainless steel line running down along the exhaust on the passengerside. I have an 82 and know I need the air pump. If I was to remove it I would have to install a heated O2.

Jim

[Craigi]

Originally Posted by Mr. Chuck

especially in climates where they have winter cold

I agree, but it's more than just very cold weather that you have to watch out for with carb aspirated engines. I have had significant carb iciing in cool, damp weather when my heat riser was not working. Even if the temp is still above freezing, the air cools to below freezing as it goes through the venturi of the carb(s), thus freezing the moisture in the air. I've had carbs completely choked off with frost. It is necessary whether your engine is warmed up or not, in most cases. A lot of drivability problems that are "unknown" and intermittant can be blamed on icing - especially on modified engines where a lot of "excess" crap is removed. Ask any pilot.

[Evolution1980]

Originally Posted by jdp6000

As for the air pump. You probably don't need it unless you have an O2 sensor.

No computers on the '80, hence no sensors of any kind. (YEA!!!!)

ArcticVette, you didn't specify if you had to worry about emissions or not. If you do, depending on how stringent they are, you will need a working A.I.R. pump. If you don't have to worry about emissions, then you can pretty much take all that stuff off the engine. With the '80 L48 engine, you can really give it some new life by taking all that off and then putting on some headers in place of the old cast iron exhaust manifolds. Going to an open-element air cleaner helps give it that clean appearance over the dual or single snorkel intake. Those mods will give you noticeable improvement on the butt-dyno.
(NOTE: If you are going to go to an open-element air cleaner, you'll need to do some minor fabrication work when you remove the existing air-ducts from the radiator area.)

PS - if you do remove it all, a decent working AIR pump setup could nab you some decent bucks on eBay... One of these days I'll get around to putting mine up there. Probably in the early spring when it should fetch the most.

[arcticvette]

thanks for all the replies, no emision problems yet that I'm aware of in Canada but that may change down the road so will keep anything that I remove from from the engine. the car came with a K&n air filter and will probably stick with that for now but would like to put on some headers and new exhaust. so many projects so little money......oh well someday right!
Mike

[Mr. Chuck]

If you remove the A.I.R. Pump and if it is like my 81, there will be a spacer on the back side of the belt pulley. The spacer alines the belt with it's drive pulley. Once I had the pulley to the A/I.R. pump three mount bolts come loose, two fell out, the third broke off, The pulley and spacer were missing; the spacer was gone, found the pulley wedged down under the eng, within some lines that run along the passenger side. Found out from local Chevy dealer that the spacer shown in the parts brake down drawings, had no P/N or dimensions . I fabricated a new one, based on the profile from the dirt image on the pulley, transferred the pattern of the mounting bolts, eye balled the alinement / position of the pump pulley to drive pulley. Gaged the thickness of the spacer at 3/4". Material at hand, was a 3/4" thick piece of iron oak wood. Cut the piece to the pattern diameter. Transferred mtg bolt hole pattern; drilled and mtg new spacer; years later it is still tight and working fine. Luckly the Iron oak wood is very hard and closed pored so it doesn't absorb fluids or damaged by the eng heat and contaminates. SMOG check guys have never questioned the wood spacer. My 81 has always passed SMOG with very low emissions reading. Hint regarding SMOG checks; always put in new air filter & drive car around 10 - 20 minutes to sure it's at operating temp and running smoothly before you get to the test center.
That assuming you have SMOG requirements in the first place. Removing the A.I.R. pump and related mtg hardware, rubber hoses, ETC will clean out quite bit of the SMOG equipment / hardware from the engine, but may also impact other air management systems. My 81 shop manual shows a rather long list of other air management system components that you may have to deal with if the A.I.R. pump is removed. It looks like a task for an experienced Corvette mechanic so your vet ends meeting all Canada requirements and still runs and performs at it's best.
Good Luck!