Raw water elbow configuration

[ageless]

I discovered a crack in the raw water elbow of both expansion tanks. Efforts to have them brazed have failed, it seems they are a brass over copper mixture. Brazing would be a temp fix regardless as there are several areas that are pitted around the Y fitting. Due to the severity of the pitting and the less than ideal configuration (the elbow runs above and parallel to the valve cover) I would like some input on my reconfiguration. I would like to cut the Y pipe off the elbow, slip a piece of 2.5" hose on the elbow, run it along the stringer to a stainless Y pipe, then attach the (2) 2" hoses that run to the exhaust elbows. Thoughts? For those with 12/71's, do you have the same elbow's? I've seen one other 52' set up with a configuration like I am considering.

[rustybucket]

Having a hard time picturing what you're describing. Any chance you got a pic or two of the setup?

I have made 90's before using brass/bronze threaded 90's and threading in a short nipple cut in half. Then you can clamp your hose to the short nipple.

[racclarkson@gmail.com]

Having a hard time picturing what you're describing. Any chance you got a pic or two of the setup?

I have made 90's before using brass/bronze threaded 90's and threading in a short nipple cut in half. Then you can clamp your hose to the short nipple.

Me too (picturing). If you mean the raw water pipe from the pump to the coolers, I saw a guy flow epoxy of some sort inside the metal and just keep rotating it until it began to set-up--redneck relining I guess. Not recommending, just reporting.

[ageless]

The elbow I speak of is in the background of this photo. I would essentially cut the Y fitting off about a foot back from where it's welded on, slip a 2.5" hose on and run it to a stainless Y I would mount to the outside of the stringer. The (2) 2" hoses seen in the ER pic would then attach to the stainless Y and run to the exhaust elbows

https://photos.app.goo.gl/ffPZcqKwEDmjMwqm7

[scottinsydney]

If I have read your post correctly, it is the stainless Y fitting is welded to the part that has got the pitting.

If so, my previous boat had 8V92s and a similar Y setup.

The cause of the pitting was electrolysis (or dissimilar metals in warm salty water.) The Y was patched at the stainless steel repair shop. We attached a tinned grounding wire to it and the motor body. The problem never reoccurred in 11 years.

Electrolysis may be the cause of this issue for you, especially if the parts are not properly grounded to the motor.

[ageless]

If I have read your post correctly, it is the stainless Y fitting is welded to the part that has got the pitting.

If so, my previous boat had 8V92s and a similar Y setup.

The cause of the pitting was electrolysis (or dissimilar metals in warm salty water.) The Y was patched at the stainless steel repair shop. We attached a tinned grounding wire to it and the motor body. The problem never reoccurred in 11 years.

Electrolysis may be the cause of this issue for you, especially if the parts are not properly grounded to the motor.

The Y that is presently welded to the elbow is the same brass over copper that the elbow is, perplexing why it is only pitted on the Y section. I would be removing that section and mounting a stainless Y downstream of the elbow.

[Captain Ralph]

Picture and previous thread here;

https://www.samsmarine.com/forums/showthread.php?33505-In-search-of-Detroit-raw-water-elbow&p=367107#post367107

If you don't like solder, Epoxy works well on clean bronze/brass.

[SKYCHENEY]

I see no reason you couldn't cut off the old Y and replace with a short length of hose and a new Y. Is that the question?

[ageless]

I see no reason you couldn't cut off the old Y and replace with a short length of hose and a new Y. Is that the question?

yes. My concern is whether I would have any back pressure issues moving it from above the engine to the stringer

[Captain Ralph]

Why would you move it to the stringer?