32-200 Exhaust system question

[Pete the Cat]

I mean, isn't raw water always trapped on the inflow side of your engine heat exchanger unless your impeller leaks?

You shut off the engine, close the seacock for the impeller before you go home, and you have water trapped on the way into the engine, right?

Well you would be right if only water was involved in the exhaust. But the engine exhaust exits into the exhaust hose and is cooled by the water---so the engine is actually is actually open to the whole exhaust system if the water gets high enough. There are a lot of things that slow and push back: when the engine is running there is a lot of hot exhaust air, highly compressed by the diesel engine, that keeps the injected cooling seawater from the heat exchanger moving through the tube. The problem is when the engine stops--if the engine is the low point in the system the water still in the exhaust will flow backwards because the engine is lower than the point where the exhaust exits the hull. I could be wrong about the dynamics of the 32-200, but that is the way it is in most boats. Generally there is a loop in the exhaust the goes high right after the water lift muffler then down hill to the exit from the hull so it limits the amount of water that flows back toward the engine. I am thinking there are a whole bunch of videos on Youtube the would show the typical water life exhaust system on an marine engine below the water line. I am thinking some of the 32-200s were outfitted differently for some reason.

 

[Pete the Cat]

My muffler (E35-3, 25XP) was above the stuffing box, but sat on a small platform which I believe was attached by screws to wood which was glassed into the hull...


View attachment 36413

This is standard in yachts, but my 32-200 has nothing like this much room to work in.

 

[goldenstate]

Well you would be right if only water was involved in the exhaust. But the engine exhaust exits into the exhaust hose and is cooled by the water---so the engine is actually is actually open to the whole exhaust system if the water gets high enough. There are a lot of things that slow and push back: when the engine is running there is a lot of hot exhaust air, highly compressed by the diesel engine, that keeps the injected cooling seawater from the heat exchanger moving through the tube. The problem is when the engine stops--if the engine is the low point in the system the water still in the exhaust will flow backwards because the engine is lower than the point where the exhaust exits the hull. I could be wrong about the dynamics of the 32-200, but that is the way it is in most boats. Generally there is a loop in the exhaust the goes high right after the water lift muffler then down hill to the exit from the hull so it limits the amount of water that flows back toward the engine. I am thinking there are a whole bunch of videos on Youtube the would show the typical water life exhaust system on an marine engine below the water line. I am thinking some of the 32-200s were outfitted differently for some reason.

Thanks. I'll have to investigate more and see if there is any other explanation for how my exhaust system works.

 

[goldenstate]

This is standard in yachts, but my 32-200 has nothing like this much room to work in.

Pete - What is the year, name, and hull # of the boat you bought? I keep track of all the known 32's in this thread:

E 32 Hull Wiki

Information offered here sometimes on an "owner states" basis, sometimes gleaned from for-sale web sites, sometimes from member profiles. In other words, there are probably errors. Readers should rely on specifics here with due care and 'caveat emptor.' Hull Series 001-024 (???)...

ericsonyachts.org

Most people put boat info in their forum signature lines - helpful when asking questions.

 

[goldenstate]

I looked over my exhaust system today and to the best of my knowledge, I have no water lift muffler of any kind.

My system looks like this:


The exhaust mixing elbow sits at the rear of the heat exchanger. There are two types of exhaust elbows for this era Yanmar. Mine is the high-loop version designed to address this situation.



I believe the mixing elbow is above the waterline, while the bottom of the engine and the low point of the exhaust pipe is below the waterline. The exhaust line then passes to starboard of the propeller shaft and is visible from the access in the rear quarterberth.



Next the exhaust passes (up, slightly) into the starboard cockpit locker.



From there the exhaust goes around the propane locker cavity and then exits the transom, roughly 10" above the resting waterline.



There is no waterlift muffler. I think there is probably water in the pipe just after the exhaust elbow, but I cannot say it has ever been a problem. Is this one reason why the later production 200's moved over to Yanmar from Universal? Quizas.

I suppose if I managed to hydrolock the engine, I would close the impeller seacock, open the compression levers on the cylinders, run the starter a few times to try to squeeze out as much water as possible, then reverse the order. And then change the oil when I got home.

 

[goldenstate]

There is no waterlift muffler.

I would add that my surveyor did not red flag this situation when I bought my boat last year.

 

[Kenneth K]

The biggest risk of a hydrolock is from continued cranking of an engine that won't start. As long as it's cranking, it's injecting more water into the elbow and exhaust hose. But if it never starts, exhaust back pressure never pushes the water out through the exhaust.

Water lift mufflers usually have a drain at the bottom. My owner's manual said to drain the muffler after 7 to 10 unsuccessful start attempts to prevent backflooding.

This seems to me to be the biggest liability to not having a water lift Muffler. Other than that, apparently the no- muffler systems have been working okay all these years.

 

[Christian Williams]

You probably have an anti-siphon vent in the hose from the Hx to the exhaust elbow.

Is that also an anti-siphon hose at the transom exit of the exhaust hose (led up above the waterline? Ericson put one on my 32-3 and I took years to figure out the purpose of a hose to nowhere).

Seems to me that a water-lift muffler's job is to prevent backflow of sea water into the engine and to quiet the sound of the exhaust.

But beyond anti-siphon devices there are other ways to prevent backflow, such as a flapper valve in the hose or on the transom. Or just closing the exhaust seacock when sailing in rough water. Anyhow, it's rare that a boat gets a fatal sea water enema. Gale at sea perhaps in crazy conditions.

It may well be that a water-lift muffler is not always necessary. Be interesting to hear what Yanmar has to say.

 

[goldenstate]

@Kenneth K Good to know regarding the continued-cranking hydrolock problem. This makes sense now that I think it through.

@Christian Yes, I do have an anti-siphon valve between the heat exchanger and where the through-put water enters the exhaust elbow:



This picture (from another site) shows what a ghastly mess the interior of the exhaust elbow can become, but also illustrates how the water flows down into the exhaust pipe:



Also if that little hose on the bronze 90 is an anti-siphon valve, that would be good news. I tend to quickly lose enthusiasm for hanging upside down in my cockpit locker figuring things out, so that can be next on the list.

I have two breather vents on the transom - I know one is a diesel tank vent. Your supposition would be a good explanation for the other:

 

[Kenneth K]

Good write-up on the topic:

Cool, Quiet, and Trouble Free Exhaust | Good Old Boat

goodoldboat.com

 

[Loren Beach]

Tom , EY often put two vents on the upper transom, like in your picture. One is for the holding tank and the other for the diesel tank.

 

[goldenstate]

Tom , EY often put two vents on the upper transom, like in your picture. One is for the holding tank and the other for the diesel tank.

Makes sense. I'll have to chase the other end of the tube on the exhaust outflow to see where it goes.

 

[goldenstate]

Good write-up on the topic:

Cool, Quiet, and Trouble Free Exhaust | Good Old Boat

goodoldboat.com

The only other point that no one has mentioned on this thread is that a boat with a lift muffler has a more flow-impaired exhaust system than one without one.

Race cars are noisy without mufflers and all 'straight piped' street cars are too - but have greater reliability and performance because their engines have less work pushing exhaust. Anything that obstructs the flow of gases will cause gas backpressure.

I suspect my engine (and any similarly plumbed) has a much easier time expelling hot gases produced through combustion than if it had a lift muffler in the outflow line.

 

[Kenneth K]

I suspect my engine (and any similarly plumbed) has a much easier time expelling hot gases produced through combustion than if it had a lift muffler in the outflow line.

Yeah, I think you're onto something. All these Ericsons seem to have had 1 5/8 inch exhaust hoses. Anybody who re-engined or rebuilt their exhaust seems to claim that 2" hose is the new standard--to reduce back pressure.

While 2" hose is 50% bigger than 1 5/8 hose, it seems to me that the "water column height" would always be a more significant cause of back pressure than hose diameter, but I've never heard a diesel guy chime in on the subject.

 

[Loren Beach]

Thanks Ken! I have learned some interesting information from this thread.

**As Young Mr. Grace used to say at the end of each episode (Are you being served?).... "You've all done very very well!"

 

[Pete the Cat]

OK. I started this thread asking where the waterlift muffler lives (or was originally installed on a Universal 25 XP powered 32-200 from 1989. I had bought 32-200 knowing the some idiot had installed a waterlift muffler, backwards(!!) directly over the the stuffing box. This could not be right so I asked folks how it came from the factory. Some folks with the same boat said (and maybe it is true) that they did not think they had a water lift muffler. Well........Today I found the old original water lift muffler buried deep in the boat. It is located deep under the water heater, just out of reach from the hole over the stuffing box. I cannot see it, but I can definitely feel it. The guy who "fixed it" just cut the hoses off it and put another one in front of it and installed it (actually he installed a wrong sized muffler and just slathered it up with 5200--I hope he rots in hell). backwards with no loop. This was done by freelance boat service in San Rafael California. Apparently no harm came to the engine. But I can see how folks might think their boat does not have a water lift muffler as it is very well hidden--at least in this instance. To get at it and replace the exhaust hose, I am going to have to remove the rectangular water heater and the shelve it sits on. Then it should be a piece of cake--but you know it won't. I am learning this boat. I am going to start another thread asking about routing the bilge pumps. This boat is very difficult because of the hull frame work they dropped in with no routing for hoses.. Anyway thanks for the folks who tried to help. I will post some pictures. there should not be any reason to replace this unless the hose falls on the coupling and rips a hole in it as it did in this case. I am guessing the guy could fit the new hose on the old muffler so he just, cut the old muffler and hoses and started a new system. Amazing. BTW. I think if might be possible to run this from the engine to the stern without much of a loop or a water lift muffler. From what I have been able to determine, my engine mixing elbow is a few inches above the waterline. But it does not, at this point, seem like something Ericson would have risked because it seems to be really close. Hydrolock can destroy an engine--water does not compress. I am going to find the muffler, put the loop over it, and do it correctly. I think I can see where the original hose loop ran down along the inside of the lazarette.
.
Ray

 

[Christian Williams]

We'll consolidate your eventual findings for the next 32-200 owner. Take lots of pictures as you explore.

 

[goldenstate]

OK. I started this thread asking where the waterlift muffler lives (or was originally installed on a Universal 25 XP powered 32-200 from 1989. I had bought 32-200 knowing the some idiot had installed a waterlift muffler, backwards(!!) directly over the the stuffing box. This could not be right so I asked folks how it came from the factory. Some folks with the same boat said (and maybe it is true) that they did not think they had a water lift muffler. Well........Today I found the old original water lift muffler buried deep in the boat. It is located deep under the water heater, just out of reach from the hole over the stuffing box. I cannot see it, but I can definitely feel it. The guy who "fixed it" just cut the hoses off it and put another one in front of it and installed it (actually he installed a wrong sized muffler and just slathered it up with 5200--I hope he rots in hell). backwards with no loop. This was done by freelance boat service in San Rafael California. Apparently no harm came to the engine. But I can see how folks might think their boat does not have a water lift muffler as it is very well hidden--at least in this instance. To get at it and replace the exhaust hose, I am going to have to remove the rectangular water heater and the shelve it sits on. Then it should be a piece of cake--but you know it won't. I am learning this boat. I am going to start another thread asking about routing the bilge pumps. This boat is very difficult because of the hull frame work they dropped in with no routing for hoses.. Anyway thanks for the folks who tried to help. I will post some pictures. there should not be any reason to replace this unless the hose falls on the coupling and rips a hole in it as it did in this case. I am guessing the guy could fit the new hose on the old muffler so he just, cut the old muffler and hoses and started a new system. Amazing. BTW. I think if might be possible to run this from the engine to the stern without much of a loop or a water lift muffler. From what I have been able to determine, my engine mixing elbow is a few inches above the waterline. But it does not, at this point, seem like something Ericson would have risked because it seems to be really close. Hydrolock can destroy an engine--water does not compress. I am going to find the muffler, put the loop over it, and do it correctly. I think I can see where the original hose loop ran down along the inside of the lazarette.
.
Ray

This is great to know. I have not been able to make my hot water heater operate, nor have I removed it during my first year of ownership.

Maybe I do have a water-lift muffler hiding under there? I should look again. I appreciate you asking this question.

I'm receiving Cruising World magazine through some organization membership and I noticed that in this month's issue there is an article addressing this very topic (prevention of sailboat engine hydro-locking). The author's suggestion is that one put:

A flapper cover on the exit of the exhaust from the transom.
A ballcock valve between the water lift muffler and the transom
(And if that wasn't enough)
A ballcock valve between the exhaust mixing elbow and the muffler.

As if when you are wrestling with a big following sea you want to dive into your locker and start shutting off valve handles. I wish I could find a link to the print article. I found it something of a head-scratcher.

 

[Pete the Cat]

OK for all of you who have a 32-200 and don't think you have a water lift muffler, I am willing to bet that you have one but that you have not found it because it is almost hidden and the hose route disguises that it goes through it. The idiot that did work for the previous owner put a new exhaust hose and muffler in my new to me 32-200. He draped the new hose over the coupling (so it ruptured and flooded the boat) and put a new (but really used) water lift muffler in and ran a hose to the stern. When I went to take out his mess, I found the original water lift muffler way down behind the water heater on the hull that had been disconnected. I think he did not want to remove all the stuff to get to it so he just threw a system over the old one. I ran my replacement hose through the old muffler (lots of doing things by feel and having to contort) and out the stern with the routing most of you have. I will attach the best picture I could get of where the muffler is, but you can't see much of it. You have to take out the water heater, lay on your stomach over where it was and peer down into the bilge--it is there. FWIW In the pictures I am showing the water heater, the water heater removed, and the shelf removed that the water heater sits on---which exposes the top (you need to look hard) of the water lift muffler. Unless you have an idiot mechanic like the PO of this boat had, this is something none of you should ever have to deal with as there should be no maintenance required ever on anything down in that hole.

 

[Loren Beach]

Maintenance Note: We replaced our original exhaust hose in 2018, because it was (finally) starting to seep rusty water thru the cover layer from the slow corrosion of the steel reinforcing spiral wire layer. 30 years of service is a long time. Even if I had not already decided to replace the OEM diesel, that hose had to be replaced.
Betcha a dime that any boat over 25 years old with the original hose is on borrowed time, hose wise.
That said, the water lift muffler looked to have some more life in it. I replaced it because the new engine uses a larger ID exhaust hose.

Maintenance Note B: we replaced the factory hot water tank way over a decade ago -- still functioned but the shell was corroding away. From anecdotal evidence, all of those with a steel shell or an aluminum inner tank start failing at 20 years or a bit more. Of course, exceptions sometimes are just statistical outliers. The one I installed is all SS, inner tank and shell. No problems.

Note C: You may find that you have seeps and leaks around fittings in the OEM "qest" tubing. Salvageable, but I replaced 90% of those runs and connections with new hose & barb fittings. No leaks since.
(Info available about that particular brand of tubing if you do a site search here.)