Has anyone solved the Fischer Panda riddle?

[Quietta]

I have just come back from a cruise on a friends boat ( Outremer 55 ) which was educational to say the least. During the voyage, an excessive amount of time was spent stuffing around with the FP AGT-4000 generator. An unfortunate necessity for these power hungry boats. The boat was 10 years old and the owner had already replaced the kubota engine in this genset because water had managed to get in through the exhaust valve and cause the cylinder to rust. The new engine was having much trouble starting and after removing the cylinder head, we realised that it also had water in the cylinder at soem time.

The exhaust elbow has already been replaced with a stainless steel unit made up to the same dimensions as the original which had rusted out and was going to cost $1000 for a replacement part.

The exhaust went down into a Vetus water lock then up into a water separator and then outside as separate exhaust/water.
The Original Outremer installation was not as per the Fisher/Panda instructions so when the engine was replaced, the water separater was installed higher. This appears to have not made any difference.

So, the question is: Is the water getting into the engine as a result of water getting pushed back up the outlet or is it evaporation from the exhaust lock coming back through the open exhaust valve and condensing on the cylinder wall? Or something else?
BTW, once these generator suffer rust on the cylinder wall this affects the compression and consequently starting, we found the best way to get the unit started was to (a) have a fully charged starting battery. (b) add an extra wire onto the glowplug and give the glow plug a 15 second serve on the 12 volt cable to the starter motor before hitting the start button.

Appreciate comments from anyone who has managed to get these units to run trouble free.

[GordMay]

NL, not FP, but See “Please don’t drown me” ➥ https://www.northern-lights.com/medi...t_drown_me.pdf

[sailinglegend]

I have had these problem three times with my ten year old Fischer Panda DC genset. Water gets into the exhaust valve which corrodes and causes loss of compression. Easily detected with a fairly cheap diesel compression tester.

But what's causing this very common problem is incorrect installation of the waterlock, looks like Northern Lights have had the same problems.

Fischer Panda is very very clear now in their latest installation manuals after much criticism in the past about their lack of detailed instructions.

So the bottom line is the water lock needs to be 600 mm below the exhaust outlet - AND - most importantly - immediately under the genset.

This isn’t always possible - but the consequences can mean water from the waterlock gets into the engine when the boat heals over. The further away from the centre line of the boat the less heal will cause the problem.

In their latest manuals they have many examples of how disastrous this can be, in my manual ten years ago there was one small paragraph, now there are about twenty pages.The Vetus waterlock installation guide was also lacking in detail.

A recent FP installation manual can be downloaded here for an AC genset:

https://fischerpanda.com/wp-content/...P-171_2013.pdf

see page 58 onwards.

On my installation I was nowhere near their recommendations so after talking to FP we came up with a solution that seems to have worked.

Get a larger waterlock - preferably two in series - so that the water from the anti syphon tube that flows back when the engine stops does not fill up the waterlock close to the engine.

And every time you stop the genset empty the waterlocks by opening their drain valves. This may not be possible but I fixed some pipes to a pump that discharged straight into the heads.

These two screen shots show the problem when mounted 500 mm away from the centreline of the genset or immediately under the genset - both at 45 degrees.

[Quietta]

Originally Posted by GordMay

NL, not FP, but See “Please don’t drown me” ➥ https://www.northern-lights.com/medi...t_drown_me.pdf

Thanks for that. In our situation, the generator is about a metre above the water level, the wet muffler is about 60cm below the generator, the water separator is up level with the generator. There is no issue of siphoning.

One thing that we have thought of is whether the 300cc engine in the generator has suffucient exhaust flow to push all of the water out of the wet muffler, and whether there is sufficient water in the pipes to flow back into the generator once it has stopped and the boat is pitching over waves.

There is no minimum engine size listed on the Vetus mufflers.

[bglad]

Run the generator then drain the exhaust and see how much water remains. If you have a side exhaust it is possible you are experiencing what sailinglegend shows in the diagrams in post #3. Stern discharge not so much.

If the generator is not mounted at the hull centerline it is possible some siphoning could occur from the raw-water supply side when the vessel is heeled. You do not mention a vented loop on the raw-water line. If one is not installed would not be an expensive addition. This would prevent water from coming in from the raw-water supply side.

[JOHNMARDALL]

There are three main ways that water can get into a marine engine - a back up from the waterlock, a siphon from the intake side of the raw water system eventually filling the waterlock and causing a back up into the exhaust manifold, and a blown head gasket.
If you would like to contact me direct I will send you a PowerPoint and an interactive spreadsheet covering the first two of these issues and will then respond to any questions you have.


All the best
John Mardall
Vetus Maxwell Boat Equipment

[roland stockham]

Good policy is to have a shut of valve on the exhaust outlet and close it when leaving the boat or in rough weather to stop any waves pushing up into the water lock. I don't think that is your problem but just a thought. Think you may be on the right lines looking at engine size vs water-lock volume.
The traditional way to start old warn diesel that lack compression is a drop of oil in the cylinder to form a seal around the rings. Can be done by spraying a bust of lube into the air intake while turning the engine.

[billknny]

If you are having this much trouble with it, this often, the problem is probably the installation, as others have pointed out. Many boat builders seem to have no idea how to install a real water proof exhaust system.

But... one thing that can happen even to good installations and varies depending on the boat and the details of the installation...

Waves hitting the hull hard enough at the exhaust outlet can force water up and over a fairly high lift without ever really syphoning. This can--slowly, over time--fill the system to the point where the water level reaches the engine, and bad things happen. A few spoonfuls every once in a while can add up to a significant amount over a week's passage if the genset is not being run.

When sailing, it is good practice to run the genset once a day to blow out any accumulated water. This might apply to your main engine too depending on the details of its installation.

[JOHNMARDALL]

Originally Posted by roland stockham

Good policy is to have a shut of valve on the exhaust outlet and close it when leaving the boat or in rough weather to stop any waves pushing up into the water lock. I don't think that is your problem but just a thought. Think you may be on the right lines looking at engine size vs water-lock volume.
The traditional way to start old warn diesel that lack compression is a drop of oil in the cylinder to form a seal around the rings. Can be done by spraying a bust of lube into the air intake while turning the engine.

Hello Roland,


The problem with having a valve on the exhaust system is that people forget to open it and close it, or at the end of a long day, can't be bothered to close it. For this reason, we recommend protecting the system against back flooding from a following sea or wake with a gooseneck, placed as high as possible in the engine room. Both the gooseneck and the waterlock should be on the centerline, to avoid overtopping when the boat is heeled



Best Regards
John Mardall
Vetus Maxwell Boat Equipment

[a64pilot]

What about the rubber flappers that you used to see on many powerboats?
My exhaust has an external flange and would be child’s play to fit such a flapper.

[coastalexplorer]

On the PDF file that Gord May posted I noticed that they required air flow around the bottom of the water lock. I had never known this before, so does any one have an explanation for the reason?

[JOHNMARDALL]

Originally Posted by a64pilot

What about the rubber flappers that you used to see on many powerboats?
My exhaust has an external flange and would be child’s play to fit such a flapper.

Dear Pilot,


A rubber flapper helps, which is why we install them on most of our transom exhaust fittings, but they are no substitute for a gooseneck in a properly designed exhaust system. By the way, I should have said in my first post on this subject that the determining factors for the size of the waterlock are the exhaust hose diameter and the run from the top of the gooseneck down to the waterlock.
Please let me know if you'd like a PowerPoint on wet exhaust systems.


Best Regards
John Mardall
Vetus Maxwell Boat Equipment

[coastalexplorer]

A current difficulty I am trying to deal with concerning installation of the Vetus wet exhaust system is that the 45 MM goose-neck is too tall for the head clearance under my cockpit floor.



The 90 degree verses straight bottom attachment Feature, (obviously an attempt to make it universal) just increases the problem.



Is a shorter version made? My only other option is to angle it to starboard the minimal amount possible/

[JOHNMARDALL]

Originally Posted by coastalexplorer

A current difficulty I am trying to deal with concerning installation of the Vetus wet exhaust system is that the 45 MM goose-neck is too tall for the head clearance under my cockpit floor.



The 90 degree verses straight bottom attachment Feature, (obviously an attempt to make it universal) just increases the problem.



Is a shorter version made? My only other option is to angle it to starboard the minimal amount possible/

Dear Explorer,


I'm sorry to hear that you're having a problem and I'll be glad to help you solve it. Please contact me direct and tell me the part number/code of the gooseneck you have and if possible, give me a dimensioned sketch of the exhaust system and the space in which it's located. As you write that the 90 degree angle is not helping, am I right in guessing that your exhaust hull fitting is a straight down tube, discharging above the water line?


All the best
John Mardall
Vetus Maxwell Boat Equipment

[JOHNMARDALL]

Originally Posted by coastalexplorer

On the PDF file that Gord May posted I noticed that they required air flow around the bottom of the water lock. I had never known this before, so does any one have an explanation for the reason?

Hello Explorer,


My connection here on the boat is very weak, so I haven't downloaded the PDF to which you're referring, but I think that there is a misunderstanding. None of our waterlocks or other exhaust fittings rely on air-cooling, they are all designed to handle the water-exhaust gas mix flowing through them. Don't let your waterlock chafe against another engine room component, but feel free to mount it direct to a suitable platform and ensure that the top of the waterlock is below the discharge point of engine mixing elbow, the more the better provided you don't exceed the engine manufacturer's maximum back-pressure.


You're welcome to contact me direct for PowerPoints and interactive spread sheets.



All the best
John Mardall
Vetus Maxwell Boat Equipment