Water in Engine

[Stu Jackson]

Tom, that appears to be the wrong kind of hose between the engine and the nipple (injection point). I'd use black reinforced.

As to the water issue, it appears you need a vented loop on the line from the engine to the nipple.

 

[Maine Sail]

OK. Let's try this. Photo shows my Volvo with a new exhaust mixing arrangement.

I hope the injection point is a tube within the bigger pipe that directs the injected water DOWN the leg and not just into it with a tee.. Potable water / PVC hose should really not be used in an engine space and that is not engine rated hose. Is there a siphon break?...

 

[JamesG161]

Nice picture. I see you put the loop in front of the boats seal loop, looks like now about 1 foot of extra seal leg. The insulation is for the exhaust heat protection for human safety?
I am curious how you replace the square faced VP rizer and made a good seal?
Jim...

 

[JamesG161]

s to the water issue, it appears you need a vented loop on the line from the engine to the nipple.

I have the same boat and it has a anti shiphon but it also discharges the water/exhaust is above the 25° starboard side. I didn't leave the helm on that tac, to double check.

The sea water pump has the high point siphon break, which is on the discharge well above his add on (actually so high it doesn't show in his pict directly behind the insulation shown).

I hope the injection point is a tube within the bigger pipe that directs the injected water DOWN the leg and not just into it with a tee

I was wondering about that too, but the height about the injection point should not flood with such a low flow. The injection of water is the triple elbowed smaller line. Exhaust is insulated.

The injection point was about 9" lower. so the added back pressure may slowly wear his pump impeller a bit more. The flow will remain the same since it is a positive displacement type. I no leaks around his pump seal ( pump is round thing to the left with two hoses) or bearing, it should be good to go.
Jim...

PS: I would have used cast iron, like the VP riser. Your engine/exhaust is protected by your shaft zinc. Galvanized is not needed.

 

[Maine Sail]

PS: I would have used cast iron, like the VP riser. Your engine/exhaust is protected by your shaft zinc. Galvanized is not needed.

For future reference, if we are going by the safety standards, it needs to be Schedule 80, and galvanized is not allowed under the standards, in the dry portion of the exhaust system.

"1.6.2
Materials used in a marine engine exhaust system shall be resistant to saltwater corrosion and exhaust products, and

1.6.2.1
shall be galvanically compatible

1.6.3
Pipe Size - Threaded pipe and fittings for the engine exhaust(s) shall be at least schedule 80 pipe or the equivalent.

1.7.1.5
Hose used in wet exhaust systems shall comply with the performance requirements of SAE J2006, Marine Exhaust Hose, or UL1129, Standard for Wet Exhaust Components for Marine Engines. All other exhaust system components shall meet the performance requirements of UL 1129, Standard for Wet Exhaust Components for Marine Engines."

Clear PVC hose does not comply as a "component" used in a wet exhaust system....

 

[JamesG161]

I want to clarify and share the OEM arrangement for the Riser in this post. Both points on hose, purge tee and siphon break should be clarified for the OP. The first pict is my OEM picture which shows my Boat Water line and would put the exhaust riser barely below AWL.

This pict shows how OEM used a purged TEE to make the flow momentum point downstream. When I visually inspected the interior, I was not impressed since is was like a 45° elbow cast in riser, but no flow erosion after 1200 engine hours. Hmmmm? Note the injection hose, Tom, as the other told you double check yours for service. Failure of your sea water purge hose would be a disaster in the making.

We kinda beat up on you by my request for a picture, but the forum experts are worried for you.
You picture stimulated a idea I will try on the group on my next post.
Jim...

 

[JamesG161]

Now for a picture of my PSS seal purge fix that I discussed earlier in this post.
Look above picture as a BEFORE fix on the pump discharge. This is the after fix.

Jim...

 

[JamesG161]

The seal loop on my Hunter exhaust looks like this.

No siphon break needed and the high point loop prevents boat heal from reverse flow.
What the OP and I have plaguing us is that the Muffler has standing water in it and in high seas and engine not running, the standing sea water can "slosh" into the open engine valve. He added another high point to stop the "slosh" as shown in his picture.

Here is a brainstorm that I would love comments on!
The problem is standing water between the engine and the LOOP in the Elevation view.

What if I installed a small drain on the muffler to remove the standing water and thus NO SLOSH?
Jim...

 

[CaptainTom]

OK. I am having a bit of a problem following the thread. Remember, I just joined the group a few days ago and I joined this thread only after it had been going for a year. I probably have lost a lot in the process.



First I am going to require a glossary of terms as you are using them. I would appreciate some clarification:





OEM-

OP-

PSS-

AWL- I know this means ____?____ Water Line I suppose this means Average Water Line?



Also, you asked me to check my injection hose as failure of my sea water purge hose would be a disaster. Are you referring to the fact that my injection hose is a domestic water line? You are right. I am embarrassed to admit that I never noticed what my mechanic installed. I was just happy to have my problem solved.



Your first photo shows pretty much how my engine was set up. You showed in your photo and stated , that your Exhaust Riser is barely below AWL. It looks to me as though the Exhaust Riser is actually barely above AWL, like mine is. This is still about 4” below the exhaust elbow—not enough clearance. My research on the web revealed to me that this is a common problem in production boats.



I also noted that you have the same “jelly jar” Sherwood water strainer on your intake. Mine was always a problem to check and became impossible after I added the exhaust loop. I just replaced it with a Groco 3/4” strainer under the floor on the starboard side of the engine compartment. Much easier to check.



In your third picture, you show a revised take off of injection water upstream of your anti-siphon valve. Why did you do this? I apologize that I did not see your earlier post on this subject.



Lastly, your diagram of the Hunter exhaust plan raise the question of what would happen if you drain the standing water from the muffler. When would you drain the muffler? In my boat, I did not have a problem as long as the engine was running, no matter what the seas. My problem occurred when I shut the engine down, at that time, a slug of water would enter, either from back pressure in the engine, or from sea surge. In either case, I cannot see when you could drain the muffler.



This would also probably drain the entire hose and loop. This would amount to quite a few gallons of water that you would have to wait, after starting, to observe if you have water flow.



I have received several posts on my subject and I will answer each one of them individually. I do not know if this is the proper way to do this—but here goes.



Tom

 

[CaptainTom]

Well, It looks like I cant answer each one of the previous posts individually, so I will try this instead.

Stu- You are right. As I said, I am embarrassed that I didn't notice until your post that my mechanic had installed water line instead of black hose. Does any one know how much pressure this line is under? I guess I can have it changed.

 

[CaptainTom]

Moderator -- I dont know how the injection interface is made. It my indeed be a simple tee connection. Can you tell me if the back pressure from the injection water could be strong enough to back feed into the manifold? Again, I now realize that the wrong hose was used for the injection hose. I suspect that the mechanic had a problem with space and bending room for the hose.

 

[CaptainTom]

Nice picture. I see you put the loop in front of the boats seal loop, looks like now about 1 foot of extra seal leg. The insulation is for the exhaust heat protection for human safety?
I am curious how you replace the square faced VP rizer and made a good seal?
Jim...

Jim- The insulation is indeed for heat protection since it resides directly adjacent to the access door. As for your first and last sentence, I am not sure what you mean. What is a VP Rizer and why do we need to make a good seal with it?

 

[CaptainTom]

I have the same boat and it has a anti shiphon but it also discharges the water/exhaust is above the 25° starboard side. I didn't leave the helm on that tac, to double check.

The sea water pump has the high point siphon break, which is on the discharge well above his add on (actually so high it doesn't show in his pict directly behind the insulation shown).



I was wondering about that too, but the height about the injection point should not flood with such a low flow. The injection of water is the triple elbowed smaller line. Exhaust is insulated.

The injection point was about 9" lower. so the added back pressure may slowly wear his pump impeller a bit more. The flow will remain the same since it is a positive displacement type. I no leaks around his pump seal ( pump is round thing to the left with two hoses) or bearing, it should be good to go.
Jim...

PS: I would have used cast iron, like the VP riser. Your engine/exhaust is protected by your shaft zinc. Galvanized is not needed.

 

[CaptainTom]

I don't know why the mechanic used galvanized. Upon reading UL 1129, I am not sure what would be wrong with using it. Also, I don't know if the pipe is Schedule 80 or Schedule 40 but I believe that it is 80.

 

[JamesG161]

Does any one know how much pressure this line is under? I guess I can have it changed.

Pressure is very low, since it only "fighting" the friction loss (minor) and the exhaust seal loop height (18" of water time 2 as the engine exhaust pressure "burps" the seal leg. That would be ~36" of water = 1.3 psi (pound/square inch)). I would think the clamps and temperature rating vs. pressure rating is the issue.

OEM= Original Equipment Manufacturer which was VP=Volvo Penta. My AWL=Actual Water Line ( lol my term defined above)
You don't know Vice President Rizer? My typo.

PSS is the name for the most popular dripless shaft seal that has a purge line that needs water to cool it (either back flow from sea or pressure flow from sea water pump).
http://www.pyiinc.com is the manufacturer.

The OEM riser has a Square plate that blots to the exhaust manifold and has a metal compression gasket.

Ok this was an Oct thread but that is not key. In the bottom right of the each Post is a unique serial number .
One page 1 my thread #9 and #11 ( referencing another thread) discusses my PSS problem that back flowed because the AWL is above the Riser, thus flowed into my engine. Thats how I found the source by pulling the Riser and with sea cock closed and verified, the water was still flowing., No more by the new installation shown.

Except for the sea water hose, IMHO ( In My Humble Opinion) you are ok.
Mixed metal that are not in electrical continuity with your sea water Zinc will eventually corrode. Pipe schedule 80 is just thicker wall than 40, both are used for high temperature/pressure service. Sch 80 gives you more longevity than 40. As long as your Zinc is on your shaft, no corrosion in OUR case. I would not change to cast iron. The galvanization should be ok.

The Original Poster (OP) and others kinda got us to the PSS seal. Off topic, just makes it hard to follow.

Lastly, your diagram of the Hunter exhaust plan raise the question of what would happen if you drain the standing water from the muffler. When would you drain the muffler? In my boat, I did not have a problem as long as the engine was running, no matter what the seas. My problem occurred when I shut the engine down, at that time, a slug of water would enter, either from back pressure in the engine, or from sea surge. In either case, I cannot see when you could drain the muffler.

I would drain to the bilge, my guess about 2 gallons of water, when I was not going to use my engine for several hours or more. Sloshing should not be a problem, but that is why iI asked the forum contributors.
Jim...

 

[CaptainTom]

Ah--that helps a lot. I was getting a little lost. I would think that there would be a lot more water in the exhaust than that. I estimate about 2 gal. in the muffler. The hose is 3", isn't that about a half gallon a foot?

I will change out the hose material soon.

Thanks guys, for all the heads up comments.