A.I.R system Q's

[tomtom72]

I looked in my FSM (Helm) & I can't seem to find a mechanical description of the system's manifold parts and how they work. I 'think' that the metal tubes on the manifolds are just a way to get air into the exhaust stream and that any check valves are at the junction from which the small tubes branch out from? Am I correct in thinking that the object is to do a post lean out of combustion/exhaust mixture in "choked mode" on cold start up so the tail pipe emissions are cleaned up?:icon_scra

I observe this much: when my 90 is cold started I hear the AIR pump running for a short while and then it shuts off & I don't ever recall hearing it at any other time during me using the car. I would have to think that it shuts down way before the motor gets to "closed loop" operation; and that in "open loop" it only runs for a short time at cold start up?:icon_scra

I've been thinking that I can drill & tap pipe fittings into the header primaries & use comp fittings to connect the small tube to the check valve/manifold thing. Or make something using my plumbing experience....maybe, but it looks like it's brazing work & not solder work....yea I know a tig or such is the ticket but I don't have that equipment. I also realize that I'm a bit out where the busses don't run on this, but I need to either install this stuff on my headers & have it work....or I need to dummy it up so it looks like it works and hope I pass emissions inspection. Does anyone sell those small pipes from the check valve to the primary header tubes? I know I come up with the stupidest Q's. Oh yea, if I somehow get this AIR piping fabed up should I do it before I send the headers for coating or after they come back from the coating place?:redface:

TIA
Tom

[Aurora40]

The check valves are those flared things where the pipes come out of the manifolds, they sort of "float" right on top of the manifolds. That's what keeps exhaust from travelling up the AIR tubing.

The AIR pump only runs at startup. I think 60 seconds on a cold start and 30 on hot? Might be 90 on cold start...

The purpose is to heat up the cats faster, because they don't work at all when cold. I believe the fresh air is to burn residual fuel in the exhaust, which will heat the cats up faster.

I don't believe the purpose is to "dilute" the exhaust, as that really doesn't clean anything up, it just makes it seem cleaner from a ppm standpoint.

I think if you were to add the tubes to headers, you'd at least want to add some stubs to them before getting them coated, otherwise you'd have to remove the coating from the area you are working on. I don't know, but I'd guess plumbing type attaching wouldn't work. Your exhaust, especially at the header, gets a heck of a lot hotter than any hot water pipe.

I'll try to get some pictures when I get home of how mine is set up, perhaps that will help in some way?

[tomtom72]

Bob thanks! Yea the way Mr H set yours up would be of great help to me. I'm trying to visualize something that I've not spent a lot of time looking at on my car. This weekend I intend to go eye up the OE install and maybe I can get some ideas from that too.

Thanks!:thumbsup:
Tom

[zr1don]

I'm working on the same project, installing SW headers that don't have the AIR injection tubes (required to pass smog) please post your solutions as you progress. I am considering cutting the tubes off my stock manifolds & welding them to the SW's. Anyone have any experience/suggestions on this approach?

[Aurora40]

Pictures (though it's quite hard to see them, let alone photograph):

http://img516.imageshack.us/img516/8119/dsc00338oj5.jpg (http://imageshack.us)

http://img517.imageshack.us/img517/6056/dsc00339ev2.jpg (http://imageshack.us)

http://img120.imageshack.us/img120/8185/dsc00340zn4.jpg (http://imageshack.us)

http://img139.imageshack.us/img139/185/dsc00341cb1.jpg (http://imageshack.us)

[RKC]

This seems to be a common problem for those of us with the visual smog inspection. I'm in CA. Just bought Uly's 1990 and took it into to smog. Didn't even get on the machine, the inspector said I had no AIR system and failed me.

I bought the SW headers but they haven't arrived yet. I think all the correct hoses are there, but those pictures should help with the hook up.

[tccrab]

This seems to be a common problem for those of us with the visual smog inspection. I'm in CA. Just bought Uly's 1990 and took it into to smog. Didn't even get on the machine, the inspector said I had no AIR system and failed me.

I bought the SW headers but they haven't arrived yet. I think all the correct hoses are there, but those pictures should help with the hook up.

I'm not sure the SW headers have AIR fittings. I know that Marc Haibec sells modified headers with AIR fittings.

Be prepared for even more pain at the Smog shop.
SW's are not CARB approved.
In fact, nobody makes aftermarket headers that are CARB approved.
Callaway at one point made some, but they aren't that much better than stock and they are extremely difficult to come by. There is/was a set on FleaBay earlier this week.

There is only one way to go from here.
Get the SW's and have the AIR tubes installed if they are not.
Make sure that your cats are 50 state legal (some aren't).
Take it back to the Smog Nazis and tell them that you'll need to see a referee.
Go to the referee and tell him that:
A. The original cats failed.
B. GM does not make them anymore.
C. It's illegal to buy a used catalytic converter
D. The original exhaust manifold & cat converter is a single piece unit.

Be prepared to prove that GM don't make them anymore and has no inventory *anywhere*.

Good luck!!!

TomC
Fellow Californicatian

[RKC]

I believe the new SW headers that have been sold on the forum give the AIR tubes as an option. I went with the headers that place the cats before the y-pipe rather than the long tube headers.

Kind of a shame because I like the the sound of the long tube Watson's and Corsa exhaust. Can't compare the performance yet, but it seems common wisdom that long tubes breathe better on the top end than shorter headers.

Nevertheless, I am prepared to answer the questions about the headers. I hope it doesn't get as far as a referee.

[Aurora40]

I'm pretty sure it is EGR, not AIR, that is an option. If they have AIR, I have not seen a picture of it.

Watson's actually did have AIR hookups available. SW's are long-tubes, I don't see why they'd sound or perform any worse/different than your Watsons.

Also, sort of academic, but I thought longer tubes did better on the low end and shorter tubes were better up top?

[RKC]

I'm going to check with SW to make sure. Hope I'm right, otherwise it look like it's gonna cost more to get it right.

I did see a recent article somewhere in which AIR tubes were added to an L-98 or LT-1 motor. Probably best to have a pro do the welding with the proper equipment. Ther are definitely kits out there for regular small block headers. The dimensions might be close enough to make work. Also the check valves aren't cheap, but I don't think the LT-5 check valve is exclusive to the LT-5. Alot of years and different vehicles seem to use the same part number.

[zr1don]

I bought SW headers as part of the "group buy" and they do not have AIR injection provisions, they do have EGR provisions.

RKC I recreated the AIR injection system on my ZR1 last year & most of the parts (mostly plumbing) was still available from GM. I have an extra diverter valve if you are interested.

[tomtom72]

Hey Bob thanks for your effort & the picts!:thumbsup:

Everyone that was in on the GP from SSW recently, mine came with the EGR tube which my 90 doesn't need and no AIR fittings which we obviously need.

Here is what I'm thinking as I also need to satisfy the Inspectors in NYS: leave the distribution system intact in the car and just find someone to make up the tubes at the primary pipes and then cut the OE tubes and do a compression fitting to connect the two. Ofcourse I'll have to do some trimming.

My problem is with all the stuff on the car I can't quite see exactly what the manifold plumbing looks like to do much ahead of time. The only other thing I can think of is just leaving the system in the car, but not connected to anything & hope that just passing the visual will be enough and also hoping that once the car is on the inspection rollers that the AIR system has no part in the tail pipe emissions.:pray Oh, and I gotta figure out how to ditch the EGR pipe!:sign10:

Again Bob thanks for your time and effort!:thumbsup:

Tom

[Aurora40]

Tom, if you can't see it on mine. Everything from the check valve to the AIR pump is stock. Only the metal tubes from the header primaries were fabbed. Basically there are two tubes vs four on the OEM stuff. The outermost primaries have AIR tubes coming out the sides. These curl around and have the correct fittings attached to connect to the factory check valves. Marc also added some support for the tubes that comes up from the flange of the middle primaries.

I wish I'd photographed them when they were sitting on his workbench, but I didn't bring a camera with me when I took the car up there.

Depending on how the threaded fitting attaches, maybe you could have the tubes welded onto the headers, and just have them left really long. Then you could curve and cut them to fit when installing, adding the threaded fittings on at the same time (assuming they don't get welded).

If the fittings do get welded on, perhaps you could cut tubes to about the right length and get the fittings added, leaving a bit of extra. Then you could basically fine tune them by adjusting how soon they start to curve, how sharp they curve, etc to take up any slack?

It does seem like it would be a huge pain though, especially without the tools and skills to weld. Have you considered buying some used Watsons instead? Many of them had the AIR tubes included. Just a thought.

Here's what the stock stuff looks like:
http://hometown.aol.com/corvettezr11990/misc/stock90hdrs.jpg
(taken from Marc's presentation on power improvements, which is why there's that arrow pointing at the pinch)

[Aurora40]

Oh, also Tom, make sure the pipes don't intrude into the primary tubes. On the stock stuff, the pipes stick way into the primaries, presumably blocking them up a bit.

[tomtom72]

Ya know it really amazes me how true that saying is about...."it's not the car, it's the people!".....or when we refer to "the Brothers of the Beast".....no one on the outside looking in would ever believe this is true.

Bob, I got a cold one for ya for all the time you took to lend assistance to me!:thumbsup:

I just sent an e-mail to HAT and figure I got nothing to loose if I get a positive response then I'm 'in like flint'.....if I don't hear back I'll understand also....no one likes people that show up to a resturant with their own steak!

In that case I have plenty of C5 & C6 friends that do business with Vette Doctors....who knows maybe with some knee pads and a lot of mouth wash I can get my headers squared away & ship shape so I can install them.:sign10:

I thank you for your effort to help me out.

Tom

[z proud]

Look at the watsons for sale on e bay ...they have air tubes connectors, I would not cut the air tubes off the stock ones... I have some photos of watsons, send me a pm with your e mail,,and I will send them to you ....but the photos on e bay are better

[tomtom72]

Just thought an update for all of us that bought the headers in the GP & we need to figure out A.I.R. plumbing at the primaries.....HAT has what we need at the website on the services tab, mostly, and look under EPROMS for the updated version of a program for the Electronic Engine Management alterations to our stock EPROMS,

Also chect out summitt racing in the exhaust section, they have a.i.r. plumbing kits for the primaries. Also these guys have some of the other parts in the system: http://catalog.autopartsgiant.com/index.html?cookieID=28F0GFGPH28F0GH5P7&clientid=autopartsgiant

Also Jegs has the plumbing kits.

:thumbsup:
Tom

[zr1don]

I've started the installation of my SW's!!! I've removed the stock manifolds (no huge problems, other than the skin I've left in numerous places around the fasteners). I live in CA and require the AIR injection system. I've taken both the stock manifolds & the SW's to my local muffler shop. They are removing the AIR injection tubes from the stock manifolds & installing them on the SW's. I will post pictures when I get them back (should be Mon or Tue).

[Hammer]

This seems to be a common problem for those of us with the visual smog inspection. I'm in CA. Just bought Uly's 1990 and took it into to smog. Didn't even get on the machine, the inspector said I had no AIR system and failed me.

I bought the SW headers but they haven't arrived yet. I think all the correct hoses are there, but those pictures should help with the hook up.

I am not familiar with CA emissions requirements but this might be worth a try.

Try calling the Air Quality Board (if there is one?) and see if they will give you a waiver on the visual AIR Injection requirement. I did that here in Idaho as they are talking of starting emissions testing in the near future and I have headers. The guy told me that he knew most or all of the parts are available for the AIR Injection from GM or other sources, except the solenoid (this makes the system work). He couldn't me spend the $1000's buying the system and then putting in a used 18 year old solenoid with a rubber diaphram that may or may not be good. He would give me a waiver on the AIR, but I would have pass the visual on the cats and pass the sniffer. No other waivers would ever be granted.

By the way, congrats on buying Uly's car, you got a great deal and a nice car from what I knew about it. Heavy mods and it ran great at the mile in Vegas.

[WB9MCW]

Boy you guys that still have to deal with the Air Nazi - CARB and all that crap I sure feel your pain --- A total PITA no doubt---

Guess we are luck here in IL now since the State is so broke(n) the GOV in is infinate wisdom decided that the # of cars on the road that are 1996 and older are so few % wise he dropped all testing for older rides.

No more rollers and all that fancy time consuming testing only the "Plug and Tell all" from the Brainbox on the 97 and up rides.

Is this actually a logical decision from a State Government?

Maybe we luck out on the Air Police but we sufffer in that many parks are being shut down and the Sec. of State plate renewals dept is totally crap azz now and good luck in getting your "courtesy renewal notice" on time or worse yet the "well we sent your sticker in the mail on bla-bla date" to bad the "mail must have lost it" -- so now you get to visit the (dreaded) DMV facility and wait in the long line to do it the hard way --- which I just did on Friday for both a "lost in the mail" and a no "courtesy renewal" notice on two of my rides. It is so bad --all of this DMV crap-- we citizens are all talking about the BS State of Illinoizy and how pathetic and what a farce it has all become in the Land-O-Lincoln.

[RKC]

I'm still waiting for the headers from SW. They seem to be willing to supply the headers with the A.I.R. plumbing for an additional cost, though that wasn't the original plan. The CARB is a huge hassle with the exhaust setup. It's definitely possible to have good performance and a clean exhaust but it costs more and is a P.I.T.A. I know a trip to a smog referee could still be in my future.

The car runs stong, but seems to have all the bugs that most 1990's have. I kind of expected that, and am used to working on Vettes. I admit I'm a little intimidated to do a serious teardown. I have a spare set of 91 Heads that I am thinking about having ported by someone. I'll have to do quite a bit of reading to figure out if I want to do the swap myself. It's certainly more involved than the SBC.

Hammer:
By the way, I was thinking if I had waited a couple weeks I might have been driving your 91 Z.

[z proud]

This was done by stainless works, I instaled them on Saturday, This was the first set of air tubes done ,,, Left side fits like a glove, The right side needs to be changed a little, I got everything to fit, but had to rerun the tube on the right side.. ALL and all I am thrilled...

[Hammer]

I'm still waiting for the headers from SW. They seem to be willing to supply the headers with the A.I.R. plumbing for an additional cost, though that wasn't the original plan. The CARB is a huge hassle with the exhaust setup. It's definitely possible to have good performance and a clean exhaust but it costs more and is a P.I.T.A. I know a trip to a smog referee could still be in my future.

The car runs stong, but seems to have all the bugs that most 1990's have. I kind of expected that, and am used to working on Vettes. I admit I'm a little intimidated to do a serious teardown. I have a spare set of 91 Heads that I am thinking about having ported by someone. I'll have to do quite a bit of reading to figure out if I want to do the swap myself. It's certainly more involved than the SBC.

Hammer:
By the way, I was thinking if I had waited a couple weeks I might have been driving your 91 Z.

Dude you're killin' me. You got Uly's car didn't you? What kinda bugs you working on, can we help?

Hey I own two, so could you. :razz:

[RKC]

Z Proud,
Those look sweet, I can hardly wait to get mine. What did you have modify on the right side headers?

Hammer,
Sorry, didn't want rub salt. So many great Zr-1's for sale now, I keep seeing them and thinking, "I would have bought that one."

Uly's car is running fine, but issues like the no start, an intermittant service ride control light,, etc. seem to pop up every other time I drive it. Not a big deal but it keeps me busy runing them down. Fortunately, there's lots of tech advice available in old threads.

[z proud]

on the right side , I re ran the down air tube so it fit the upper conection the lower rubber hose I removed it and added a 10 inch rubber hose to complete the conection, I added a photo of it....It is to close to the right a arm..I am going to talk to Jim Watson on Monday so maybe they can correct this...You will need to get O 2 extenders, gaskets , Jeffvette has them , any hardware store you will need 3 3.5 LONG bolts and nuts for the left cat

[z proud]

pic

[RKC]

Thanks for the pictures. That's a realy tight fit on the right side.

[tomtom72]

Thanks z proud for sharing the picts & info!:thumbsup:

The right side primary air pipe looks real close, no chance a bit of gentle persuasion toward the cam cover solves that issue?

Also in the vein of asking the obvious.....the black colored plumbing is scavanged from our OEM set up and attached to the the set up provided by ssw...the small primary pipes and fittings colored silver??

TIA
Tom

[z proud]

Thanks z proud for sharing the picts & info!:thumbsup:

The right side primary air pipe looks real close, no chance a bit of gentle persuasion toward the cam cover solves that issue?

Also in the vein of asking the obvious.....the black colored plumbing is scavanged from our OEM set up and attached to the the set up provided by ssw...the small primary pipes and fittings colored silver??

TIA
Tom

Yes,the black is from our oem set up and attached to the silver set up provided by ssw. :thumbsup:
spoke to Jim Watson today about the changes, they were hit by a storm last night and are with out power for a few days.

[z proud]

FYI a photo of the watson air tube one photo from e bay and one I took, on the right side they skiped the first pipe and went to the second and 4 th pipe cyl #4 and #8

[ZZZZZR1]

This was done by stainless works, I instaled them on Saturday, This was the first set of air tubes done ,,, Left side fits like a glove, The right side needs to be changed a little, I got everything to fit, but had to rerun the tube on the right side.. ALL and all I am thrilled...

Wow those came out great! I wish SW would have done it from the beginning though, but what can you do.

:thumbsup:

[tomtom72]

FYI a photo of the watson air tube one photo from e bay and one I took, on the right side they skiped the first pipe and went to the second and 4 th pipe cyl #4 and #8

I think that is the way Mr. Haibeck does the air tubes. One pipe into the first & last primary on each header. It kind of makes sense that as long as you get enough air injected into the exhaust stream, that's all you need to get the emissions to comply.

Hummmmm....that kind of brings me to a "what if" theory. I'm wondering if using the EGR pipe on the right side header to work as an inlet for the AIR system to use as an air injection point....that solves one header for an AIR fitting. Then all I have to do is get fittings put on the left header.:icon_scra

Thanks again guys for sharing all your info....this helps me a good deal.:thumbsup:

Tom

[tomtom72]

I feel that since I started this thread about the stuff the group purchase recently bought from Stainless Works that I should offer up this info from Jim at stainless works.

They will install the A.I.R. tubes on the headers. Just send them back with the amonunt they quote you and you'll be able to keep the smog police happy. They will also remove the EGR tube for us 90- 92 owners included in the price of the AIR install.

I gotta say that Jim was very quick to offer up help!:thumbsup:

Tom

[zr1don]

Pictures of SW headers w/stock AIR tubes installed. I did a test install, looks like they fit fine.

[zr1don]

How much is SW charging to install the AIR tubes?

[ScottZ95ZR1]

I received an email from Jim at SW today that stated it is a $200 option retail for new orders but that they would add them to previously purchased headers for their factory cost of $140 plus return shipping.

[tf95ZR1]

I sent Marc Haibeck my Jeal headers. On a 95 I needed an additional fitting for the EGR. Locobob also recommended extra bungs for direct future tuning. Not cheap, but quality work and easy fit.

http://i529.photobucket.com/albums/dd335/tf95ZR-1/ZR1Exh.jpg

Old and new before switching over the components. What a difference!