Hot section replacement -- advice needed

[Clucas]

My P30 has a late model raw-water cooled A4 that to date has been extremely reliable. As the snow has begun to diminish, I decided to break out my late winter punch list. Among the many little things was the fact that my exhaust’s hot section was clearly wrapped in asbestos, so -- donning a mask, gloves and eye protection -- I began unwrapping to discover that beneath the asbestos wrap was a layer of fiberglass (?) batting (oh thank you, dear PO). The batting did such a marvelous job of retaining moisture against the hot section for many years that I wondered if I might be able to crush its corroded remains in my hand. I tried and it remarkably held together – at least initially… but I had a feeling I was going to have to go there very soon. Read on, dear readers…

I discovered the short section of exhaust hose between the hot section and the water lift muffler was split along its cover and decided to replace it. I worked for awhile to loosen the hose from the muffler and hot section and had a 4-in piece of the hot section break off and disintegrate in my hands. <sigh>

Soooo… I’ll be building a new hot section but know that the flange on the manifold is not likely to budge and will probably need to be drilled and re-tapped. I’m looking to my fellow Afourians for some guidance as to next steps… access to the manifold side of the engine is quite good from the quarter berth access panel. If the flange bolts need to be drilled-out and the manifold re-tapped, would this require the manifold to be removed? I’ll start the PB treatment, but believe it’s only a matter of time before they snap based on the amount of corrosion (pix to come…). Better to bite the bullet and attempt to remove the manifold?

Chris

[sastanley]

Chris, When I rebuilt my hot section I did not have to remove the manifold...I'd recommend a perusal of the various hot section solutions in the exhaust section. I made mine out of galvanized pipe, but most have decided galvanized off-gasses too much, so they make it out of 1.25" black iron.

[jpian0923]

Much easier removing carb from manifold and then the manifold.
Check the link below. Read the whole thread. It's helpfully to the whole process.

http://www.moyermarine.com/forums/sh...8&postcount=21