Wet Exhaust System

[Triton106]

Hi All,

I own a Pearson Triton and am in the process of redoing my fuel tank which is forcing me to redo my exhaust (because the new fuel tank location is where the old waterlift was). I am planning to switch to Vetus waterlock which many Triton owners have used with great success since it fits under the engine in the bilge area. However, the typical route of the exhaust goes from the aft end of the engine manifold to the waterlock (which is under the bilge facing forward with the wet exhaust outlet facing forward as well). The exhausted hose is then attached to the outlet from the front of the engine and routed around the engine back to the transom where the wet exhaust is expelled. Attached below is a picture of a project Tim worked on showing such an installation [Tim, sorry to post your picture without permission. Please do not kick me off the forum ;-)] In this particular instance the engine is a Beta and the picture shows the forward end of the engine looking toward the back. The gray plastic container under the engine is the Vetus waterlock.



I understand that Atomic-4 manifold has two openings one faces forward and the other faces the back. I would like to route the exhaust from the forward end of the manifold through the waterlock (which is again under the engine in the bilge but with inlet facing forward and outlet facing the back). I can then attach the exhaust hose to the outlet from the back of the bilge. Does it matter if the exhaust is coming out the front or the back of the manifold? Do I make any sense?

The alternative solution is to build a platform offset to the port side of the A-4 behind the main bulkhead. The issue is that (1) it is offset to the manifold outlet by approximately 12 inches (easy for water to flow back into the manifold when the boat heels over), and (2) it is only approximately 4-6 inches below the turn in the exhaust lift (best practice is 12 inches at any angle of heeling). My solution is to install a ball valve before the wet exhaust hose reaches the waterlock. After I motor the boat out of the marina and the Oakland estruary I would turn off the engine and shut off the ball valve to prevent any water from seeping back into the manifold. The advantage is that I don't need to buy any new waterlock or more hoses (a saving of couple hundred dollars). But I am not sure if anyone has tried this setup and if it works (eg. ball valve might be leaky or it is too much hassle). If you could point out any obvious (or not so obvious flaw with this set up) please let me know.

Thanks and best regards,

Ray

[Tim]

1. It doesn't matter which direction the Waterlok faces, although there is a dedicated inlet and outlet on the unit that cannot be reversed. Some models have an inlet that rotates to help align the inlet hose. There is usually a drain fitting on one end of the Waterlok which should ideally angle towards the low end of the installation to allow for muffler drainage, though in practice this isn't really very critical and shouldn't alone drive the whole installation process.

2. I think having to close an exhaust valve every time is at best inconvenient and impracticable, and at worst potentially dangerous to the engine. You wouldn't want to try and start the engine by accident with the valve closed. A valve to close off the exhaust system is a fair installation for a boat headed offshore, but not for regular daily use. (In my opinion.)

3. Pictures of your own setup and its specific obstructions would be most helpful, as always.

[Chris Campbell]

I completely agree with Tim about the inconvenience of having a valve in your exhaust system - if you need the motor in a hurry (as well seem to at one point or another) you have another step to take before you can have it running - which might lead to some regrets.

On the other question, that of taking the exhaust off of the front of the A4 manifold - all of the Yankee 30's which left the factory with an A4 (which is most of them) had the exhaust routed off the front of the manifold where it connected through the head bulkhead to the standpipe muffler. Repowering these boats is complicated by the fact that most other motors don't have this "either end of the manifold" feature. Seems you ought to be able to use it with impunity! Of course, as with all things A4, a call to Moyer wouldn't go astray.

I hear nothing but good about the Vetus waterlocks - it's what I'm planning to stick in my Yankee to replace the aforementioned standpipe - assuming I determine that it fits and I can route the exhaust out of the bilge. But I digress.

Good luck - and post pictures, of course!

Cheers,

Chris

[Triton106]

Thank you Tim, Chris for your insights. They are very helpful.

I am very much leaning toward Vetus under the engine solution. But before I pull the trigger on the purchase here a couple of picture of what I was thinking of doing (i.e. installing the Naqualift Silencer). The first picture shows the platform I built for that purpose. Picture two shows the front view of the Atomic 4 with the hot section riser in the background. The high differential between the bend of the hot section and the Naqualift inlet is approximately 12 inches. However, the horizontal distance between the two is approximately 18 inches. That is where the issue is - when the boat is heeled 30 degrees the waterlift will be higher than the hot section bend. I apologize for the atrocious condition the engine appears as I am in the middle of redoing the fuel tank, exhaust, etc...



Question on Vetus under engine installation:

(1) I oringially thought that it is easier to route the exhaust from the forward end of the engine to the Vetus Waterlock under the engine and then route the exhaust from the Vetus outlet throught the bilge passing the prop shaft to the counter exit. However, my manifold does not offer the option of the exhaust though the forward end. So I am back to the way Tim did it (see my original post). My question is that the space between the prop shaft and the hull is very tight (see picture three). I read on one of Tim's project the idea of using a fibergass connector for that area. It still looks tight. Is there any risk of the exhaust being worn through after a few hours of motoring?

(2) I cannot seem to find engouh clearence to drop the Vetus Waterlock under the engine. How does one get it under the engine? (see picture four above).

Thanks and best regards,

[Tim]

You'll need to open up some access beneath your engine in order to fit in the Vetus. If you want it in there, do what you need to do to make it fit. This may mean creating a removable section of the platform on which your battery is currently sitting, or maybe you can install it further forward in the bilge, where you can access it through an existing hatch? It doesn't have to be directly beneath the engine. Moving it forward will be fine if the space exists, but will of course require more hose, etc. If the waterlift is well below the level of the manifold exit (which it will be in the depths of your bilge), the extra hose length won't pose any problems. Try and locate it so that you can install the hoses after installation (which means that you can then service them without major contortion).

However you run your exhaust hoses, ensure that they cannot and will not chafe on the propeller shaft or coupling. It is very tight at the aft end, and it may not work, with or without the FRP elbow. The hose can never touch this, ever. Consider running the hose beside the engine instead. And remember that the hose, when attached to your theoretical elbow, will add at least 1/2" in overall diameter, plus any interference with your clamps.

If it's important enough, why not consider replacing your existing A4 manifold with one that contains the forward exit that you are hoping to use? This might be worth the effort and cost if it can greatly simplify your installation by minimizing hose runs and contortions. Remember, you're doing these installations for the long haul, so consider what you want down the road too, in terms of serviceability and access.

Another option might be to build a new standpipe directly above the Naqualift location that you show (assuming you have lots of vertical clearance there), and rerouting your raw water injection point below the high point (and on the downstream side) of that new well-insulated standpipe. This would theoretically eliminate the potential for water backflow into your manifold, barring ridiculous circumstances that no system is likely to withstand anyway.

Squeezing a modern exhaust into the overly-tight confines of an old engine room is an exercise in frustration, compromise, and torturous hose runs. Short of reconfiguring the whole engine room and aft end of the boat, there is only so much you can do to make it fit, and it rarely ends up being "ideal". Few things ever do.

[Triton106]

Thanks Tim!

Another option might be to build a new standpipe directly above the Naqualift location that you show (assuming you have lots of vertical clearance there), and rerouting your raw water injection point below the high point (and on the downstream side) of that new well-insulated standpipe. This would theoretically eliminate the potential for water backflow into your manifold, barring ridiculous circumstances that no system is likely to withstand anyway.

I considered this option but the resulting hot section pipe will reach around the bulkhead up the side and come down in a very long and winding sprawl that look like an octopus arm (I should hide my emotions better). I am also concerned that with that long a pipe section it gets heavy and with the engine vibration it may leak soon than later.

Squeezing a modern exhaust into the overly-tight confines of an old engine room is an exercise in frustration, compromise, and torturous hose runs. Short of reconfiguring the whole engine room and aft end of the boat, there is only so much you can do to make it fit, and it rarely ends up being "ideal". Few things ever do.

I am learning the fact now. When I started the fuel tank project I was very optimistic and found a good solution for it. I never dreamed solving the fuel tank problem just means creating another problem for myself. Sometimes I just want to put a outboard at the back and go sailing. I have not sailed for more than three months because this and various other projects.

Thanks again for your help.

Best regards,

[Quetzalsailor]

I had no particular difficulty and had apparent success putting that same Vetus aft of the A4 in our Morgan 27. And, I followed the instructions, too! The original setup was a high wet muffler rigidly plumbed from the A4, the A4 was originally bolted down to the engine beds. My new setup involved new engine beds, engine mounts, new 2" wet elbow from Universal, a vented loop for the engine cooling water injected to the elbow, the Vetus ended up just low enough relative to the elbow and was bolted to pats of epoxy goobered onto the bottom of the boat aft of the stern tube, the 2" cooled exhaust was led up alongside the cockpit and drained down to the original 1 3/4 tube through the transom. The piece that I cannot remember is whether I had to ell the exhaust up to the elbow, and how far; I don't think that I did. I met all the height requirements but exceeded none. (The similar setup in our NE38 / Yanmar GM30 uses a 10" nipple to raise the elbow for a similar Vetus.)