Exhaust leak at manifold

[79Scott]

Does the integral head exhaust manifold have "donut" gaskets between the manifold and exhaust Y pipe? The reason I aks is one of the areas around one of the connections was leaking pretty bad. I removed the Y pipe and it looked like there are donuts there but hell if I can get them off. OR is the exhaust manifold connection point tapered to fit the Y pipe?

 

[smoothandlow84]

Mine had exhaust donuts installed. I saw them when I replaced my exhaust with duals and headers.

 

[79Scott]

How the hell do you get these things off? I have one that is damaged and the damn thing wont budge

 

[smoothandlow84]

I used a heavy rubber mallet ( loaded with steel shot)....a couple good blows it popped out. You could also try a punch and a hammer too. They will need replacing anyway when reinstalling exhaust.

 

[79Scott]

I used a heavy rubber mallet ( loaded with steel shot)....a couple good blows it popped out. You could also try a punch and a hammer too. They will need replacing anyway when reinstalling exhaust.

popped out or off? Mine are stuck to the manifold side. I'll give it another whirl tomorrow

 

[smoothandlow84]

It will take some effort if the donuts are stuck in the manifold, but with some prying and some wd40 or the like, they will come out.

 

[79Scott]

Manifold is off and there are no exhaust gaskets......maybe I should have been more clear. My truck has the manifold that has two exhaust outlets. it appears to me that the manifold is tapered to accept the exhaust pipe? is that correct?

 

[smoothandlow84]

Hmmm...don't recall ever seeing a manifold with two exhaust outlets. Can you post a pic, that would help determine the issue. I thought you were referring to a 350 block.

 

[79Scott]

bottom looking up. I have the 250ci with the 3 speed on the column.

 

[smoothandlow84]

That's gotta be it. By the looks of it, the exhaust down pipes more than likely are a tapered fir, then the clamps hold the exhaust down pipee to the manifold. On the 305 and 350, there are exhaust donuts that are inserted into the manifolds before the exhaust down pipes are attached with spring tensioned steel clamps.

 

[Georgeb]

Just need to make sure they are nice and clean, tightned evenly and the mating part of the pipe isn's deformed. I personally prefer that over having a dohnut.

 

[79Scott]

This one needs a bit of welding on it as well as several broke off manifold bolts removed. I going to drop it off at the machine shop today and see what they have to say. I do have a new "y" pipe on the way so we will see how it goes back together.

Are these dual outlet exhausts rare?

 

[Keith Seymore]

Are these dual outlet exhausts rare?

I dont' think so. My '80 with an integral head straight six had the dual outlets.

Incidentally - they make for an easy dual exhaust set up. The 80 system goes down the left side, and the '79 6 cylinder system swoops under the drive shaft and exits the RH side.

If you can score a '79 system then a few judicious cut and welds will net you a true set of duals.

K

 

[79Scott]

The truck is all original, I bought it from the orginal owner. it does have the crossover that swoops under the driveshaft. I actually stopped at the machine shop today and they are pretty sure they wont have an issue repairing this one.....

 

[79Scott]

Hey guys, I have another question. Why would the truck leak antifreeze when I removed the exhaust manifold? Are there water jackets that run between the intake and exhaust manifolds?