Anyone familiar with the 454 engine with the A.I.R. system?

[fgutie35]

I removed the piping that comes out from the exhaust manifold which is part of the A.I.R. system. I was about to plug the holes with 5.9L cummings oil drain plugs like someone recomended here, but when I was cleaning the holes with a wire brush, a tube came out from one of the holes. It is about 3 to 4" long and is shape like a star at the end, and about 1/4" before it, it has two square holes. My question is: Should I remove these little pipes before plugin the exhaust holes? or should a leave it alone? does it help to remove them? or would the engine still work the same with or without them? i??

[tiinytina]

This is from experience. We put a naked KN air filter on our 1987 454 so those tubes were not connected.. BUT the AIR system which I think provides heated air into the carb  from the manifold... is important for this engine if you are planning on running in the cold... our mileage plummeted to 3.4 mpg when we did this mod. and ran it in temps of around freezing. The carb needs the heated extra air to avoid freezing up  etc....  just my 2 cents on the topic so I wouldn't remove these from the 454.... the carb (edelbrock quadrajet) is designed for them...

Tina

[RV Mech Tech]

fgutie35  -  A.I.R. stands for Air Injection Reaction system
- in the older carbureted engines (non computerized) there was always some unburned fuel that went out the tailpipe - you can usually smell it if you are driving behind them
- the AIR system is just one of the band-aid methods that the auto manufactures used to try and decrease the emissions coming out the tailpipe- they already had  an engine management system ( computer - some HDuty vehicles already had TBI injection with a minimal computer control by 88 ) in the works with fuel injection, electronic ignition control etc. that  would effectively reduce what comes out of the tailpipe
- what Tina has mentioned about the heated air for the carb was the Early Fuel Evaporation system (that I mentioned in another post) and as Tina says is important for cold weather operation but it was also used to maintain a minimum combustion temperature to make sure that as much fuel would be burned in the combustion chamber
- this system is separate from the AIR system - the AIR system used an engine driven air pump to pump air into the already heated exhaust manifolds and would ignite any unburned fuel before it reached the catalytic converter- loading up the cat. converter with fuel was a good way to destroy it as many people found out
-  also your Winnie is a 1988 -  are you exempt from emission testing in Texas for that year? - if not you may have to keep all the emission control systems intact or they will not pass the vehicle so check for this first - also the carburetor is calibrated to run a leaner mixture and ignition timing may also be affected as far as specification go - some trucks over a certain GVW may only require an  AIR injection system only and nothing else - a friend of mine had a 1990 Chev full size extended van and his was exempt without any emission equipment so check first
- if you do remove it keep an eye on the spark plugs for a lean mixture as this may cause damage in the long run - those earlier engines were not built like they are today for emissions and you had differences like different camshaft  and ignition timing, leaner jetting in the carb, etc and a lot of people experienced a very poor running engine with an increase in fuel consumption when they disconnected anything - the newer engines are built to reduce emissions with electronic controls and that's why you do not choke when you drive behind them- hope this give you some insight. 

[fgutie35]

Thanks for all the replies. I already removed the whole system due to a part failure, that dealership says they don't make anymore. I just got the inspection sticker done. I still have the standard emissions system (EGR). I just removed the extra emissisions system (AIR). which I don't need to pass inspection.

[RV Mech Tech]

fgutie35 - you mean they let you disconnect some items and still pass  the MH ?

[fgutie35]

Well, since the A.I.R. system was specifically designed for MH's built for Canada and California, Around here, nobody knows what it is or better yet, they would never know it was there if it was. If you know what I mean. My MH doesn't even have Catalytic converter, and that one, the guys at the inspection, are aware of it, but I figure, because of the year model, they exempt it.

[RV Mech Tech]

Good -makes things easier for you - here in Ontario Canada if you even have your PCV valve pulled out of where it goes then they fail you - most private shops are usually good when it comes to inspections but not the DOTransport - I remember when I got my  propane and natural gas license ( as an engine fuel for cars/trucks) when we were near the time limit for the final exam an Ontario DOTransport officer came in to take the exams when we finished- go figure!!! -  for most vehicles before 1996  (OBD 1 emission systems) they don't worry too much now since most of those older vehicles are off the road but anything after 1996 ( OBD 2 )  they are strict here - if you do remove the AIR system then pull out the tubes as well - also you can get specific plugs in brass from a brass fitting supplier (anyone who sells propane fittings will have these) for the holes in the manifolds. 

[fgutie35]

Thanks RV Mech Tech. My fear was that one of the holes tread was stripped, so I was going to permanentally plug the hole by re-treading with standard tread instead of the 1.5 pitch that it had, then put a regular 1/2" pipe plug with a solder paste that hardens with heat, so it is going to be permanent. I did not want to find out after the fact, that I was suppose to leave the tubes in there. For the rest of them, I used a M22x1.5 oil drain plug for a cummings 5.9L Turbo Diesel engine. Expensive ($7.49ea) but it works very well. Now I can continue with the project. Thanks again!!

[RV Mech Tech]

Your welcome! - those tubes are just extensions to direct the air straight at the exhaust port and burn the fuel  at that point before it travels down and collects in the catalytic converter (if you did have one )  if the manufacture only put the AIR and EGR systems on then that was enough for that year for that specific vehicle and GVWeight with that engine to satisfy the Federal  emission standards - that's why you get differences of what is installed on what vehicle.

[mhtwin987]

It appears I'm in the right place to ask a question or two about the AIR system.  I'm going to remove mine completely.  My RV is registered as an antique plus I live in a county that doesn't do emissions inspections so don't have to worry about that. 

I've read where an M22 x 1.5 plug works for part of this mod.  I think I'm correct in asking, do you put this plug, after removing the injection tube, where the injection tube connects to the header?  I went to Lowe's the other day looking for this size of bolt and it seems to be a lot bigger than the hole in the header.  Maybe I'm looking in the wrong place on the header. 

What length does the plug have to be?  I found them online for $3.50 each and want to buy the correct part.

Thanks in advance for any info.

Mike   

[gary19734]

If you cant find plugs that fit which i couldnt find easily.Just cut the tubes close to manifold pinch them shut and have them mig welded shut thats what i did much cheaper than the plugs and your not taking the chance of stripping them wich happens very often since they have been heated and cooled so often   Gary   

[ClydesdaleKevin]

Anyone know if the exhaust manifold from the TBI  setup for the 454 will bolt right up, gasket and all, to a 454 set up for a carburetor and the AIR system?

I'm asking because in my research about Banks header systems, the Banks headers that are for a carbureted engine have the AIR tube threaded holes on them, so I'd have to plug them.  The Banks headers made for the TBI engine don't have the AIR threaded holes but seem to be pretty much the same otherwise...makes more sense to me to buy the TBI version if it will bolt right up to the head.

Thanks!

Kev

[jkilbert]

I know that there are some differences between Gen 1 and Gen 2 BBC  and SBC. My best suggestion is to call the tech line for either Summit Racing or Jegs. They should be able to give you the definitive answer.


John

[tiinytina]

Kev you may want to call Banks Power and ask... I'm not sure which one we ordered at this point as I told the guy that we were removing the dual AIR system. they were very helpful...
Tina