Well, I found my put put sound. The right side exhaust manifold is cracked. The put put started sounding...well, pretty good as the hole got bigger. :lol: but I have to fix it. The book says to put penetrating oil before removing the bolts.. WD40 OK? Am I going to have bleeding knuckles when I'm done here.. How easy do those bolts come out? Also, is ZIP the best place to buy a replacement? Any help is appreciated.

 

ZIP is good. Exhaust manifold bolts can get a little cranky over time due to the heat, but they usually back out readily enough. You'll have more problems with the nuts on the pipe than you will with the manifold bolts. Been there, done that.

 

Penetrating oil = PB blaster for me. WD40 will not work.
For my 350 with A/C changing the right side exhaust manifold took extra time to remove the A/C unit first. The rear most bolt did not come out of the exhaust manifold while the manifold was in the engine compartment - too tight against the HVAC housing. Just loosen the bolt and lift it out with the manifold. Don't know about skinned knuckles - I wore gloves. Don't forget about the heat riser valve when lifting the manifold up and over the fender. It could fall out.
Replacement manifolds are available on ebay and this forum if you want to buy from an individual. Probablably less expensive also.
Roger

 

I'd suggest using Liquid Wrench penetrant. That's the yellow can. There is a Liquid Wrench product in a blue can which is NOT penetrating oil, but is in fact a WD-40 type product.

Penetrating oils work best if you give them a couple of heat/cold cycles. Spray the manifold bolts when they're warm (not hot!), let them cool down, then repeat another time or two before putting the twist to 'em.

Good luck!

 

What is PB blaster or is that it's name?
Also, did you remove the bolts from the top or from under the car? It looks more accessable from underneith.
Also, can't I just cut the 3 bolts holding the pipe together?

 

This is what I found..

"68-80 Manifold, 350, 2, w/A.I.R. holes" $185

Since I've never ordered anything like this before.. PLEASE HELP..

68-80 Manifold.. ok that's easy..
350.. got it
2.. no clue
w/A.I.R. holes.. yea I think I need this.. What is it for?

 

indeed wd-40 will not cut it. Nothing like snapping an exhaust bolt/stud to ruin your day! Get out there soak it heavily for what abt 15 mins is my rule of thumb, put on some thick gloves and slowly apply pressure. Do not bounce on it just work it slowly.

This might sound over cautious, but prevention saves a poopieload of $$$!

The A.I.R system was not on all models 68-82, I do not know about 1980 yr, so *shrug*. There are some companies that make emission legal headers that have A.I.R fittings also btw. They are cheaper than some exhaust manifolds and give you a little performance boost. Just something to consider.


[Modified by 1976C3, 11:46 PM 9/12/2001]

 

It will be a good idea to use a 6 pt. socket to break them loose. $185 for one manifold sounds steep. I think you should be able to find replacements at your local auto parts stores for about half that price. If your 80 L48 is similar to a 79 L48, you don't need the A.I.R. holes.

 

PB Blaster is the name. You can get it at the local NAPA store, other parts stores may have it. I have seen used manifolds for $25-$75 on ebay. I just bent over the fender with a socket wrench & box end wrench and removed the bolts after three soakings of PB Blaster - no problem.
In another week or so I might have an extra manifold w/o AIR fittings I don't need.
Roger

 

Koz;

Corvette recyclers routinely carry perfectly fine exhaust manifolds such as you need for about $75, plus shipping. If you don't have any in your area, e-mail me and I'll gladly give you the name and number of the place I got mine.

 

When my exhaust manifold in my 78 cracked, I used that excuse to buy headers. Pretty cool

 

Sensei Earl - Did your headers bolt right up or did it require exhaust surgery?

1976C3 - How can I tell if my '80 uses A.I.R. ? From what I saw there is an exhaust flapper looking thing (yea I'm real technical here :lol:) that goes between the manifold and the pipe. It has a hose attached to it that went under the air breather. Is the A.I.R. something built into the manifold that you can't see? Also, can you point me towards some emissions legal headers? I think I'm going to just replace with stock but I'd like to read about them.

RMS73 - How did you know you didn't need a manifold with A.I.R.? If I don't need it then I'd be interested in what you have.

 

For the cost of a new exhaust manifold, or a used one, you might as well
spend the money on headers !

I'm doing the same thoughts - my right manifold is leaking at the butterfly valve.
Used ones run about $75. New ones are about $175. Headers are in between that range. So if you were thinking at any time of getting headers, now is the time. You will have to get a new front pipe at least, maybe the rest too.

I may have to remove my manifold and machine/grind a new surface on the connector. Hopefully it's not too hard to get off and back on the block.

 

Is it possible to have A.I.R. fittings on the drivers side and not on the passenger side? Also the dealer wants $450 buck to change it.. Say's it's a big job and that's only if everything goes smooth.. Broken bolt and it could be more. This doesn't look like a big job.. other than removing the bolts.. right?

 

I dont know anything about the A.I.R systems I just know what I have heard/read about them.

The hose our refering to is a flexible type metal hose going from the front of the drivers side manifold to the air cleaner, correct?

That hose is part of the thermostatic air cleaner.

I think you can tell if you have a A.I.R system by the presence of a big bolt on item sort of like the alternator or ac on the front of the engine. I think so anyways.

I would look at my exhaust manifolds to see if any plumbing went into them. The hose I mentioned slips on and off ez enuff. If you do not have any fittings/sensors going into the exhaust manifold, then:

-Buy a pair of dynomax headers for what $80 bucks. *shrug*
-Soak the manifold bolts in penetrating oil, and slowly work the bolts loose.
-Unhook your exhaust at the manifold & y pipe.
-Hang the dangling exhaust pipe under the car coat hanger etc.... (temp bubba fix!)
-Install the headers/gasket

At this point you got a loud ****, and have the y-pipe and old manifold removed, and the exhaust is hanging in for a short run to the muffler shop to piece the exhaust together.

It is mot likely to run straight headers where you are, but if you get pulled explain you have a broken exhaust system and are going to a exhaust shop rite now and you will usually be ok.

Anyway its ghetto sounding but will get your problem fixed and be cheaper/better than a dealer doing a stock manifold swap for you.



[Modified by 1976C3, 3:36 PM 9/14/2001]

 

Thanks.. I called the dealer to see if he could explain it.. He said to look at the manifold and see if there are any pipes tapped into it. Passenger side I said no BUT on the drivers side it does.. There are 4 small pipes tapped and screwed into the manifold. Wondering if Bubba was here..

 

I dont think it matters which side the pipes are on. I do not know what to tell you if you have the a.i.r system and its working.

Sorry

 

On the early 70's there are four connections on each manifold. One connection at each exhaust port. The AIR pump should have a connection for two hoses, one hose to each exhaust manifold. Each hose has a check valve connected into it. About 3" away from the exhaust manifold the hose attaches to a metal tubing manifold that feeds each exhaust manifold. If the AIR is on the car it should be piped to both exhaust manifolds. If it only goes to one manifold then I'd say "Bubba was there".

Roger


Roger

 

OK.. Bubby was here.. Drivers side has A.I.R. connections.. passenger side doesn't.. That leads me to believe that either the passenger side broke once and was replaced with a no a.i.r. one or Bubby was trying something (more power) and removed it from one side for Bubba reasons.. The car went through emissions before I got it and passed by allot so I don't think I need the passenger side A.I.R to pass. Question.. Since I have to replace the passenger side should I try to reinstall A.I.R. to that side? All I would need is the pass. side collecor and plumbing since I'm already feeding the drivers side. I feel like I would be throwing away money in doing so BUT it would keep the car original. Will I loose any MORE power since I'm already running the pump for the drivers side? What would you all do? I'm not ready for headers cause I don't want to cut up the existing exhaust. I know the car is not a collectable but it is.. for the most part.. original..