My New-to-Me '74 Dodge W200 Power Wagon had an exhaust leak in the area of the right exhaust manifold. I didn't see any cracks, but the previous owner was a beginner welder and there are lots of bird-dropping-type excess weld material in the pipe flange area.

Also, there was no gasket found as I disconnected the pipe at the flange.

This is the first LA small block I have owned as well. Not sure what the manifold/pipe flange connection is supposed to look like, in factory condition.

Is there supposed to be a flat flange gasket, a donut, or both??? Is the Pipe Flange supposed to be loose/free to rotate around the flared pipe end, or is the flange fully welded to the pipe???

The outlet surface of the exhaust manifold has an inner ring that extends down into the flared opening in the flanged exhaust pipe.

I'm also concerned that the heat-riser might be leaking at the bushings, though they may be fine.

Here is another photo of the pipe and flange welded together. Is this somewhat correct, aside from the poor weld/grind job? Is the flange supposed to be welded on, or should it be loose to rotate/turn on the flared pipe end?

Its a flat metal gasket if IIRC.That and I believe they should be welded solid not moving .Its been years since I had stock pipes on the ones I owned.NAPA should have the gasket.If the manifold is flat like the pipe its flat if its donut shaped it takes nothing as its seals in the pipe.They make a 2 piece part to replace the flanges when they rust away.Just did two on my kids Durango as his pipe is excellent.Rocky

Thanks Rocky.

The Exhaust Manifold is not flat. It looks more like the picture below, except that it has the heat riser too.

The exploded view in the Factory Repair Manual shows what appears to be flat gaskets.

that's what mine look like, there should be no gasket. You have to move the pipe flange around to seal it on the manifold. The flange shouldn't be welded on the pipe. At least none of mine have been.

OK, I had to go out and look! I have 2 small block exhaust manifolds in my shop.

One is an aftermarket 360 truck manifold set up for the emission tube. It has a flat mounting surface and would have had a flat flange with a metal gasket. Most of the flat flange pipes had the flanges welded to the pipe.

The 2nd manifold is an older non-emission tube manifold. It has a tapered flange at the pipe joint that is part of the manifold itself. It would have had a pipe with the bell opening and a metal flange, but no gasket. Some versions had a loose flange, other versions had a welded flange.

Bottom line, the manifolds dictated a flat or tapered pipe. Flat flanges were welded to the pipe and the belled pipe could have had either a welded flange or a loose flange.

I'd bet your version had a tapered pipe with a loose flange that had a pipe failure at the bell, and someone "fixed" it. Your about to find out that most Y pipes are pricy and some are hard to find these days.

Be prepared for those that are going to tell you that so and so has them listed for $50. Having the pipes listed, and having them in stock and ready for delivery are not the same, and back ordered exhaust pipes change in price from listing prices. Been there done that. Gene

Thanks Dave and Gene.

The most recent owner was in his mid-twenty's or so and didn't have much money to spend on this restoration project and not much experience welding.

When he bought it (not running, at least he got it running before he sold it to me) one of the modifications he performed was to cut up the Y-Pipe, remove the round factory muffler and convert it to dual exhaust.

For now at least, I plan to leave it Dual Exhaust, but will need to re-weld and repair the system.

Not sure If I should try to cut off the pipe flange, re-flair the end, etc, or clean up the existing welds, grind the flange surface flat and use a flat gasket with copper silicone to achieve a seal or some other approach.

My guess is that this is what it looked like originally, unmolested:

I believe you can buy the stub with flange to fit your manifold, then weld it into your system.

R.

That one above looks to be the welded piece. My Y pipe has that cone shaped type connection. I just bought it for my 76 D200
Although it is a 318.
This is what fits the manifold posted.

Thanks, and Thanks for the Photo of the pipe for your '76. Good to see.

Upon closer examination of the Factory Service Manual, the drawing makes it look like mine should have a loose and not welded flange, but then again, I'm not certain how best to proceed with what I currently have in place.

DC

I've got some stock down pipes floating around my yard. You're welcome to bring yours, and find one that works. I believe I have one still attached to a 360 manifold

I'll be home Friday and Saturday

Thanks Kevin. Will likely drive out or at least meet you somewhere between Friday if possible.

I may have this solved by then, then again, maybe not and I'll need yours if you can spare it.

DC

Tonight I looked at the Left side exhaust. The Flange is Loose on the bell shaped pipe. Pretty sure the Right side was the same until the previous owner "Fixed" it and converted to dual exhaust.

Kevin, which scrap yard do you go to and how much $$$ do they pay per pound of scrap?

I go to a place in romoland. Not sure on price per pound. I I ly go there because everywhere else has a 3 day hold on payment.

Why? You looking at buying the down pipes? I was gonna toss them in with the other stuff (vents, glove box, etc) and when I get home Thursday, I have a couple more boxes to dig through for the straps, and arm rests.

Might want the Down Pipes.

Also, I have lots of scrap metal too, plus scrap car batteries, and at some point in the future, I would like to clean up the property. Plus, it would be nice to get some cash in return for my efforts at loading and transporting the scrap to a recycler.

Was hoping for $0.10/pound. I believe there is a Scrap Metals place at Mission and Milliken, near Ontario Pick-A-Part.

Of course this is Wisc. but sheet scrap is at $140.oo a ton now.
Prepared will be better.
Batteries are different, but they will pay you for all you have.