Mixing Elbow

[frank balcer]

While in the process of rebuilding my Hurth transmission I am going thru my exhaust components and to my surprise under the insulation I find my mixing elbow is homemade. Its an 1 1/4" "T" with a 1/2" barbed fitting in the "branch". It has worked since I got the boat so I'm guessing I will replace in kind. Any comments? Thanks in advance... Frank

 

[Ross]

I would probably go with a wye fitting.

ShapeWyePipe to Pipe ConnectionNPT x NPTSystem of MeasurementInchMaterialCast Red BrassMaximum Pressure Range0 to 999 psiMaximum Pressure (0 to 999 psi)200 psiSpecifications MetAmerican National Standards Institute (ANSI) and American Society of Mechanical Engineers (ASME) and American Society for Testing and Materials (ASTM)ANSI SpecificationANSI B1.20.1 and ANSI B16.15ASTM SpecificationASTM B584ASME SpecificationASME B1.20.1

Pipe/Thread Size

Source : McMaster-Carr

 

[frank balcer]

Thanks

Thanks Ross, will see about getting this from McMaster Carr....

 

[Stu Jackson]

Here's another picture

A friend bought an M25 off eBay. It's working and in his garage for installation on his Pearson 10M to replace an old A4. This is a temporary rig of galvanized, he'll use black steel on the boat, but this works just fine for testing. Not sure whether 90 degrees water intake or the Y that Ross suggested makes any difference to the flow, since the exhaust gas is blowing the water out anyway. The Y seems more elegant and the connection to the water is pretty much the same. Lots has to do with the space you have available.

 

[Roger Long]

This is a temporary rig of galvanized, he'll use black steel on the boat, but this works just fine for testing.

Looks like a good way to fill up a cylinder with water and destroy the engine with hydrolock or just get enough water in it on shut down to rust the cylinder and kill it that way. Water will continue to flow out of the cooling water line after the exhaust stops blowing.

 

[Stu Jackson]

Roger, I understand, but the water inlet should (and will) have an antisiphon loop on it to preclude just that. Does the arrangement of or at the mixing point then make any difference? This particular engine is sitting on a dolly in his garage, not in the boat. Yet.

 

[Ron McCoy]

Are you kidding me? That's a big headache waiting to happen. Instead of trying to "jury-rig" plumbing that was never intended for engine exhaust/heat, why don't you just install the correct mixing elbow? Obviously, you have too much time on your hands IMHO.

 

[NYSail]

Original equipment in places like this..... A mixing elbow is not that expensive that it would cause one to jury rig in my opinion. An anti siphon valve will stop the water, but the water still in route will find itself in the wrong place. Also, what happens when the siphon break clogs with salt like they do sometimes? One more thing to always wonder about.

 

[Richard19068]

Original equipment?

Original equipment in places like this..... A mixing elbow is not that expensive that it would cause one to jury rig in my opinion. An anti siphon valve will stop the water, but the water still in route will find itself in the wrong place. Also, what happens when the siphon break clogs with salt like they do sometimes? One more thing to always wonder about.

Is there such a thing as an "original equipment" exhaust elbow for a Universal diesel engine. The only ones I have seen are fabricated from iron pipe.

I think the one shown in Stu's picture will not look like that when it is in the boat. Most likely there will be an elbow (90 degree street ell?) after the exhaust flange and the water injection will be after the elbow in a piece of pipe in a vertical orientation so the water will not have a chance to run back into the engine.

 

[Stu Jackson]

Thanks, Richard

You got the message that the last two folks didn't seem to understand. The question was can this type of fitting (T fitting with an insert for raw water) work, rather than either the built up pipe concept or the Catalina exhaust riser with its welded on nipple? That's all. Richard, the Catalina exhaust risers are what I'd call OEM. Picture is the one I got from Catalina in 2003 for our C34.

Please note that the raw water nipple is NOT below the level of the exhaust output or connection to the manifold flange end.

We know that the POSITION of this particular T in the picture, related to the engine, will NOT be where it would be located when it's on the boat.

I thought I'd mentioned the engine was on a dolly in the guy's garage. Guess I didn't, but it ain't on the boat. The raw water pump source is a bucket which is emptied the second the engine stops, so no water is gonna back up into the engine because it's not under the water line with an open seacock.

So, back to the question...

 

[Mike Holibar]

Have a look at this site. http://www.vetusweb.com/manuals/files/Exhaust_systems/030412 r02 03-03.pdf. At around page 15 it shows some good detail on dos and donts of exhaust sytems. Too many elbows and too small a bore are common faults. I am currently installing a new 20hp diesel in our club tender and maximum permissible back pressure is 1.5 psi so no elbows, minimum bends, shortest possible run.
Water injection is about 4" below exhaust manifold. exhaust then going down to vetus waterlock muffler, then riser the top of which is no higher than the injection elbow, then a straight run overboard. Manifold is about 16" above waterline .

 

[Richard19068]

OEM for Catalina

You got the message that the last two folks didn't seem to understand. The question was can this type of fitting (T fitting with an insert for raw water) work, rather than either the built up pipe concept or the Catalina exhaust riser with its welded on nipple? That's all. Richard, the Catalina exhaust risers are what I'd call OEM. Picture is the one I got from Catalina in 2003 for our C34.

Please note that the raw water nipple is NOT below the level of the exhaust output or connection to the manifold flange end.

We know that the POSITION of this particular T in the picture, related to the engine, will NOT be where it would be located when it's on the boat.

I thought I'd mentioned the engine was on a dolly in the guy's garage. Guess I didn't, but it ain't on the boat. The raw water pump source is a bucket which is emptied the second the engine stops, so no water is gonna back up into the engine because it's not under the water line with an open seacock.

So, back to the question...

Thanks for the picture Stu. That looks good but I guess my problem is that it's OEM for Catalina, not from Universal, and wouldn't necessarily fit layouts in other boats, such as my O'day.

 

[Stu Jackson]

Thanks for the picture Stu. That looks good but I guess my problem is that it's OEM for Catalina, not from Universal, and wouldn't necessarily fit layouts in other boats, such as my O'day.

Richard, of course, but that's just the point.

Here's how it works: Universal "steals" tractor engines from Kubota, hikes up the prices because of heat exchangers, and sells them to boat builders. There is NO "Universal exhaust riser" because each boat is different and the boat builders, NOT the engine manufacturers, have to make the risers. There is NO way Universal could know the boat layout to make the risers. Universal does not make risers, never has, they stop at the exhaust manifold flange, period.

This is not a chicken and egg thing. The engines came first that the builders chose to install in a boat design that came well after the engine was made.

I'm sure it's the same for, say, Yanmar. If I recall correctly, Yanmars have the exhaust riser nipple built right into the elbow on the engine, so the exhaust hose to the muffler is up to the individual boat design.

Actually, Catalina was "kinda nice" to produce aftermarket replacement exhaust risers. They could just as well have said "Go make your own" after the originals failed.

And my pictured riser doesn't fit a Catalina 30 or 36, it's only for my C34, Mark I, 'cuz the C34 Mark II moved the muffler so the riser is different! Each boat is different, again, that's the whole point.

 

[Richard19068]

Richard, of course, but that's just the point.

Here's how it works: Universal "steals" tractor engines from Kubota, hikes up the prices because of heat exchangers, and sells them to boat builders. There is NO "Universal exhaust riser" because each boat is different and the boat builders, NOT the engine manufacturers, have to make the risers. There is NO way Universal could know the boat layout to make the risers. Universal does not make risers, never has, they stop at the exhaust manifold flange, period.

This is not a chicken and egg thing. The engines came first that the builders chose to install in a boat design that came well after the engine was made.

I'm sure it's the same for, say, Yanmar. If I recall correctly, Yanmars have the exhaust riser nipple built right into the elbow on the engine, so the exhaust hose to the muffler is up to the individual boat design.

Actually, Catalina was "kinda nice" to produce aftermarket replacement exhaust risers. They could just as well have said "Go make your own" after the originals failed.

And my pictured riser doesn't fit a Catalina 30 or 36, it's only for my C34, Mark I, 'cuz the C34 Mark II moved the muffler so the riser is different! Each boat is different, again, that's the whole point.

Right, I understand, that's why I can't find an OEM riser for my boat and have to make one... I don't think the other posters realize that. Thanks

 

[jibes138]

Same thing on my O'35

My pipes finally rusted out and had to replace the whole mess. Used a water injection elbow but the alignment of the outlet hose to the Vetus is not very good. I looked around the web yesterday and found a 90 degree water injection elbow but the attachment is with a v-band clamp. That means the mating part will likely have to be made on a lathe. IF only someone would start a business to provide exact replacement oem exhaust systems we would all buy them in a heartbeat. Just another boat headache. Maybe best to just farm it out to the yard and pay the bucks to get it done professionally?
The elbows I found are Universal part number 200488 or 200526. They look like they might be used on a generator but I can't be sure, an installation where it would attach directly to the exhaust manifold. Cost for the smaller one is 178 the larger is 286. You can search on the parts numbers and find a source.

 

[Richard19068]

My pipes finally rusted out and had to replace the whole mess. Used a water injection elbow but the alignment of the outlet hose to the Vetus is not very good. I looked around the web yesterday and found a 90 degree water injection elbow but the attachment is with a v-band clamp. That means the mating part will likely have to be made on a lathe. IF only someone would start a business to provide exact replacement oem exhaust systems we would all buy them in a heartbeat. Just another boat headache. Maybe best to just farm it out to the yard and pay the bucks to get it done professionally?
The elbows I found are Universal part number 200488 or 200526. They look like they might be used on a generator but I can't be sure, an installation where it would attach directly to the exhaust manifold. Cost for the smaller one is 178 the larger is 286. You can search on the parts numbers and find a source.

Thanks for pointing these out. I have seen them but they don't fit. I think I'm stuck with the homemade cast iron pipe system.

 

[Steve Dion]

I do not think that this is an issue on the Yanmars. It appears that they only have a couple of mixing elbows available for their engines. The Yanmar elbows are typically cast iron (like the manifold). There must be some exceptions.

 

[drh1965]

I used a Universal Mixing Elbow on my M18 rather than refabricating a black iron pipe elbow to replace the original mess. I'm very happy with this part. It is very well designed with a water jacket and does not require an exhaust wrap. It is aluminum with brass fittings. Highly recommended over the DIY back iron pipes.


http://shop.torresen.com/ships_stor...=EXHAUST+ELBOW+RISER+KIT+1.25&sectionid=10480