Universal 5432 exhaust elbow parts?

[SteveOO]

I've been working on engine overheating issues due to low raw water flow in a 1980 38ft with the universal 5432. I've already cleaned the heat exchanger, replaced hoses and flushed the system with barnacle buster. Last piece in the system is the exhaust elbow.

Photos here:

http://imgur.com/a/AhN3GDs

Finally got that off, and it's definitely clogged, at least where the water enters the elbow. I'm going to clean up this existing elbow, but would like to get a backup to have onboard. There are no markings on this one, is it just a generic.. yanmar thing? It looks very similar to this one. Not sure how to find a replacement for the rectangular mounting bracket that goes to the exhaust manifold, or a gasket for that.

Is that lower 90 degree elbow that goes to the manfold another specialized part, or something more specialized? Would you even try cleaning my existing pieces up and reinstalling? I'm not sure if this is normal wear and tear but still functional, or on the brink of failure. Thanks for any input.

 

[Christian Williams]

Would you even try cleaning my existing pieces up and reinstalling?

I would, if I could judge the carbon buildup inside and feel good about the connection of the new raw water hose. Personally, I don't feel the need for a spare for this part.

Somebody will correct me, but my impression is that this isn't a complicated component. It just has to deal with very hot water and salt. They're often cobbled together after 40 years, judging by discussions here. Mine appears to have bronze fittings, but I've never taken the heat shield fabric off to see what the pipe is. No idea if it is "standard", or if there was a standard for marinized Kubota engines branded Universal.

 

[SteveOO]

Would you even try cleaning my existing pieces up and reinstalling?

I would, if I could judge the carbon buildup inside and feel good about the connection of the new raw water hose. Personally, I don't feel the need for a spare for this part.

Somebody will correct me, but my impression is that this isn't a complicated component. It just has to deal with very hot water and salt. They're often cobbled together after 40 years, judging by discussions here. Mine appears to have bronze fittings, but I've never taken the heat shield fabric off to see what the pipe is. No idea if it is "standard", or if there was a standard for marinized Kubota engines branded Universal.

View attachment 49443

Thanks for the reply, yeah my elbow seems in decent shape, just needs a cleaning. I was thinking a spare would be good as I've seen people post about needing a new elbow when they're out in the middle of nowhere, but maybe it's very unlikely to fail. I agree that the exhaust elbows can be cobbled together. I guess the main specific part I need to find is the gasket for the exhaust manifold. The existing one is disintegrating.

 

[reginaldobaker]

@SteveOO you can buy gasket stock, in sheet form from places like McMaster carr etc. you then just cut out whatever shape needed from the stock.
Perhaps an auto parts store would carry exhaust gasket material as well.
If the engine is non turbo you’re unlikely to see exhaust gas temps above 800F, so that’s roughly the heat threshold needed for a gasket.

 

[reginaldobaker]

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

the graphite gasket stock above, according to the spec, could be one option (seems the item above has a 10 week lead time at present moment).

For cutting bolt holes in the material there are sharpened cylindrical stamps sold at hardware stores like harbor freight. One may be able to sharpen a piece of pipe/tube to cut holes as well. Otherwise a razor blade works well.

 

[bsangs]

Last season I replaced the entire exhaust elbow setup on my Yanmar 3GM30F with a stainless steel version from HDI Marine. https://hdimarine.net/product/gm-kit/ Much easier replacing the entire thing instead of removing only the elbow. Give them a look, they likely have what you need.

 

[Afrakes]

Thanks for the reply, yeah my elbow seems in decent shape, just needs a cleaning. I was thinking a spare would be good as I've seen people post about needing a new elbow when they're out in the middle of nowhere, but maybe it's very unlikely to fail. I agree that the exhaust elbows can be cobbled together. I guess the main specific part I need to find is the gasket for the exhaust manifold. The existing one is disintegrating.

If you're in the market for a spare, let me know.

 

[SteveOO]

Thanks for the tips everyone. I've bought some gasket material and will give it a try to cut my own.

One thing I'm just curious about on my exhaust elbow - the raw water injection point is on the forward (engine-side) of the elbow, but I'd expect it to be on the other side of the elbow so the saltwater always flows down and aft, and not into the exhaust manifold. Maybe inside the elbow, the raw water is actually plumbed up over the rise?

Just curious incase I ever replace it with totally different one, I'd assume I want the water injection point past rise in the elbow.

 

[SteveOO]

Last season I replaced the entire exhaust elbow setup on my Yanmar 3GM30F with a stainless steel version from HDI Marine. https://hdimarine.net/product/gm-kit/ Much easier replacing the entire thing instead of removing only the elbow. Give them a look, they likely have what you need.

thanks for the link, seems nice to go stainless steel whenever possible on a boat

 

[Christian Williams]

injection point is on the forward (engine-side) of the elbow,

Photos in this thread suggest that is common: https://ericsonyachts.org/ie/threads/t-fitting-in-raw-water-circuit.21064/

 

[SteveOO]

injection point is on the forward (engine-side) of the elbow,

Photos in this thread suggest that is common: https://ericsonyachts.org/ie/threads/t-fitting-in-raw-water-circuit.21064/

Good thread, thank you. Yeah it does seem common, so I'm sure it's normal, I'm just slightly confused by it.

 

[SteveOO]

Okay yeah I can see in the elbow now that the water injection is plumbed up and over the arch of the elbow before mixing with the exhaust

 

[Kenneth K]

Yes, the Yanmar elbow is double-walled to keep what would otherwise be the hottest part of the riser cooler. I can often touch the top of mine with a bare hand even after extended motoring. It's a good reason to have the old one cleaned and inspected before re-using. Rust-through of that upper chamber could be fatal to your engine. An engine shop I used to go to (Tacoma Diesel) said they routinely particle-blast those elbows to clean them. I'd probably just go new--it'll be good for another 20+ years.

Also, try to minimize the number of corners the cooling water has to transit as it enters the Yanmar elbow. Each corner is a trap for sediment buildup as the cool water is rapidly heated by entering the hot exhaust elbow.

 

[SteveOO]

View attachment 49472
Yes, the Yanmar elbow is double-walled to keep what would otherwise be the hottest part of the riser cooler. I can often touch the top of mine with a bare hand even after extended motoring. It's a good reason to have the old one cleaned and inspected before re-using. Rust-through of that upper chamber could be fatal to your engine. An engine shop I used to go to (Tacoma Diesel) said they routinely particle-blast those elbows to clean them. I'd probably just go new--it'll be good for another 20+ years.

Also, try to minimize the number of corners the cooling water has to transit as it enters the Yanmar elbow. Each corner is a trap for sediment buildup as the cool water is rapidly heated by entering the hot exhaust elbow.

Good info, thanks Kenneth.

 

[Pete the Cat]

Last season I replaced the entire exhaust elbow setup on my Yanmar 3GM30F with a stainless steel version from HDI Marine. https://hdimarine.net/product/gm-kit/ Much easier replacing the entire thing instead of removing only the elbow. Give them a look, they likely have what you need.

I haven't done this yet, but my diesel repair buddy, a professional, says that SS is the way to go--he claims that it rarely clogs like the iron cobbled versions adapted for marine use. The Yanmar factory supplied elbows generally do not clog as much because they are double walled in the critical areas (Yanmar builds engines for boats, they are not cobbled tractor engines). I carry an extra black iron elbow on my Ericson with a 25XP, though it seems a bit absurd, because you need some huge pipe wrenches and a mondo vise to separate the stuff out of the exhaust flange on the engine--even then I have had to use MAP gas. I have tried to clean them with very mixed results--I tried to chisel the stuff out and it seemed hopeless. In my book, this is a maintenance and regular (once a year or two) inspection item--folks should not wait for an indication of a problem to inspect/maintain. The biggest clogs seem to be where the salt water suddenly cools the exhaust gas.

 

[Christian Williams]

where the salt water suddenly cools the exhaust gas.

Yes, many of the recent issues with cooling systems have turned out to be that very fitting. I'm adding it high on my list of troubleshooting steps.

 

[Frank Langer]

Unfortunately it doesn't seem easy to do an inspection of the exhaust elbow. On my 2 cylinder 5416 diesel engine the thick exhaust hose is almost impossible to remove without cutting it apart. Then removing the exhaust elbow from the engine is not possible without huge tools. The same problems exist at the 90 degree piece at the stern transom before it exits the boat.
If I'm wrong, and there is an easy way to check if the exhaust elbow or that transom piece is filling with carbon deposits or corroding from the inside, please let me know.
Frank

 

[SteveOO]

I’ve finished the project, and the boat no longer overheats. The water injection part of the elbow was totally plugged. I’ll eventually replace the elbow and the related couplings, but good to know the system very well now.
A few notes for future googlers:
There had been some limited sea water flow out of my exhaust, but it turns out this was only from the siphon break point, where the raw water hose rises between the heat exchanger outlet and the exhaust elbow injection point. Now I know that when the boat is idling, the exhaust water output should be a bit rhythmic, as it builds up in the pipes and then gets pushed out. The totally consistent fine spray (no rhythm) indicates only the siphon break water is coming through the system. Another indicator of low or no flow is a very hot exhaust hose after the muffler, or a very hot top of the exhaust elbow.

Cleaning the exhaust elbow was difficult. I tried degreaser detergent, wire brushes, pressure washer, but in the end what worked by far the best was just diesel fuel to break apart the muck of soot.
I think a decent way to check the exhaust elbow in-place for plugs is the remove the hose to the injection point at the elbow (making sure you’ve shut off your raw water intake valve). From here you can visually inspect a bit, and probe with a pipe cleaner.
Making a gasket for the back of the manifold was not too hard, but it was difficult to get a good seal. I had to really scrape and clean all surfaces, and in my case had to install new manifold studs.
I found the best way to do a flow test of the raw water wasn’t to hang out by the exhaust with a bucket in my kayak, but to hook the raw water pump up to a 5-gallon bucket of water. Then you know exactly how much is drawn into the system in a minute.
Repair logs on my boat indicate 1.8 GPM at 1200 rpm is normal (1980 Universal 5432 with 3-inch heat exchanger).
Barnacle Buster worked great for cleaning the heat exchanger (I removed it and soaked it in a bucket). I also briefly ran some more diluted stuff through the raw water system, and it exposed a rusted-out fitting at the siphon break. Some people recommend against running any of that acid through the system, but others say it’s fine.

 

[Pete the Cat]

Unfortunately it doesn't seem easy to do an inspection of the exhaust elbow. On my 2 cylinder 5416 diesel engine the thick exhaust hose is almost impossible to remove without cutting it apart. Then removing the exhaust elbow from the engine is not possible without huge tools. The same problems exist at the 90 degree piece at the stern transom before it exits the boat.
If I'm wrong, and there is an easy way to check if the exhaust elbow or that transom piece is filling with carbon deposits or corroding from the inside, please let me know.
Frank

Here are a few potential solutions to the inspection problem.
1.) I bought a cheap ($60 on Amazon) endoscope for looking at lots of boat things. You need one with a side view camera and illumination--split screen is a nice option. Check the focal length because the very cheap cameras tend to have a limited focal length.
2.) Removing the hose can be a hassle, but will, at some point become necessary. I might suggest buying a nice new flexible exhaust hose (the type used for going around corners and is ribbed, and more expensive) for that first run after the elbow. And install it with a little RTV--not to seal it, but to isolated the rubber from the metal. I have also used dish soap and a heat gun to loosen and install them.
3.) If you are using an iron elbow, you can (once you are sure of the construction) run a drill down the raw water inlet on the elbow and that may, or may not, clear things up. I have noted that any crud that comes through all the rest of the system (ground up seaweed, critters, flotsam) tends to turn to solid blocking material right at the injection site because this is where the crud first encounters big heat. You might have a carbon block on the inside of the elbow at the injection site or the goo might have simply been collected here. I recently removed a blockage right here on my 25XP and why I strongly support a sea strainer on intake that Ericson did not seem to provide.
4.) I keep an old wire coat hanger as part of my tool set. I find amazing uses for it.
FWIW.

 

[Loren Beach]

I strongly support a sea strainer on intake that Ericson did not seem to provide.

On this point, EY did not install a strainer on our boat in 1988, either. I added one, and clean it out yearly. IMHO every boat should have one.