Exhaust (hot) leaks @ manifold nipple- 1972 A4

[mtnsailor]

My 1972 original A-4 (in a Morgan 30) leaking before muffler (temp. patches with hose clamps got us through summer). A mechanic is assisting--photo attached- concerns: 1) manifold exit appears a 1.25" iron nipple screwed in- so, many questions on its removal (after old pipe is cut from muffler & manifold is unbolted from the block). Pictures we see of A-4's exhaust systems appear to show a removable flange with 2 bolts into the manifold (like my Palmer engines); but on mine, just a very corroded nipple. The mechanic is expecting to need a new exhaust manifold. (?)
2) possible to purchase a strong-enough, Stainless-steel 1.25" dia. flex. hose to replace this Exh. piping from Manifold to muffler (~5.75" long and 2.25" of offset)?

Possible useful info: this A-4 was overhauled by Moyer M.Inc. in 2005 (owned then by Stuart Tuller; S/V= Nuage; Rhode River)
Thanks, John Reeves Mathews, Va.

[JOHN COOKSON]

Any chance of cutting the pipe off at the manifold and buying a flange from MMI? The flange will be theaded for 1 1/4" pipe. You might not even have to take the manifold off the engine.

Maybe I'm not understanding all the ins and outs of the issue here..........

TRUE GRIT

[Al Schober]

John,
Not sure what you've got there under all the corrosion, but not much looks like its worth salvaging. You may be able to save the manifold, but paying a mechanic will make replacing the manifold cost effective - doesn't take too many manhours to equal the cost of a new manifold.
What's that thing on the left in the photo? I see the exhaust coming in and a rubber hose which I assume is water out of the manifold. Do the two ever mix or is that just a jacketed pipe? I doubt if it's actually a muffler.
What would help is a sketch of the whole system, elevation and plan view. Where is this engine in the boat? Any room for a water lift or a Tartan-style mixing can?

[BunnyPlanet169]

Hmmm

I don't know that the manifolds were ever directly threaded, isn't there always a threaded exhaust flange that bolts on? They are almost sacrificial (as this photo seems to show.) I can imagine I see a exhaust flange just to the right of the double hose clamp. It may be missing bolt heads from the rather spectacular corrosion.

You might try cutting the pipe, remove the manifold from the block, and try to make the rusty flange come loose... I had mine faced in a machine shop for $20 and installed 2 helicoils. But I was doing all the work.

I'm with Al, though... If you can't see some quick progress, a new one will be more cost effective.

[67c&ccorv]

Don't know what your budget is but I think the mechanic is right...looks to me like you will most likely need a new water jacketed exhaust (or convert to water lift) and exhaust manifold.