Date   

Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

Bill & Judy Rouse <yahoogroups@...>
 

Jamie,

Isolated ground is probably not something that you learned in electrical engineering school, but it is an important thing to understand in a marine environment. Amel uses an isolated ground system where the DC negative IS NOT part of the engine frame. You will notice this with the temperature sensor and other sensors. Most marine engines have a single wire going to the temperature sensor because the engine is ground. Your Amel has an isolated ground and there will be two wires. The only time the DC negative is connected to the starter is when the start switch is turned to start.

Your alternators will also be isolated ground alternators. I know a Bavaria owner who failed to install the correctly grounded alternator and his entire saildrive became a sacrificial chunk of metal.

As to what ABYC thinks is important, I am not so sure. Just because they are American, does not mean they are right. I would argue a number of their publications, but that is for another day and another subject.

Good luck with your new engine...did you state what engine you plan to use?

Bill
BeBe 387



On Thu, Dec 3, 2015 at 7:35 PM, James Wendell ms42phantom54@... [amelyachtowners] <amelyachtowners@...> wrote:
 

Eric, I guess I don't understand what you mean. How does the negative get disconnected after the generator starts? It would have to be connected in advance to get the starter to even work. Most negatives go directly to the generator frame which is integral with the starter.
Can you help me here?
Jamie
s/v Phantom



On Thursday, December 3, 2015 1:06 PM, "sailormon kimberlite@... [amelyachtowners]" <amelyachtowners@...> wrote:


 
Hi,
My generator has an isolated ground and the negative is not connected to the start battery except when the generator is starting.
Fair Winds
Eric
Kimberlite Amel Super Maramu #376
 
 
From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Thursday, December 03, 2015 9:41 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis
 
 
Kent, again thanks for the kind words about my engine failure on Phantom. Just to confirm my comments, I am not suggesting the exhaust des ign was necessarily at fault, but in my case the layout of the system certainly could have exacerbated my engine failure. In any event, if I can take steps to improve with my new engine, I will.
 
If I can comment on your AC findings, I understand that Amel deliberately does not connect the AC earth to the DC bonding grid. That, of course, is totally opposite from US regulations that mandate that connection for safety, a practice to which I fully subscribe as an electrical engineer. There is also the absolute "no-no" of connecting AC neutral to earth anywhere on the boat unless you have an isolation transformer.
 
The exception, however, is at a separately-derived power source. For a shore power connection, the neutral-to-earth bond would be at the shore power source in the marina. For a generator, it would be at the generator. When the automatic transfer switch (ATS) is in shore power mode, it ensures the neutral is connected only to the shore power feeder and not the boat. It also ensures the grounding systems are not interconnected, since the neutral is not connected to the boat systems. Further the generator case will be connected to earth, since the battery negative for the starter lands on the frame. When the ATS is switched to generator, the neutral "should" be tied to AC earth, since it "should" be bonded to PE at the generator. You should verify the connection between the blue neutral wire and the green/yellow PE. If it is connected you are safe; if not, and you had a fault in an AC circuit to earth, the neutral would not have a return path to its source and the AC current would try to find an alternate path - not good.
 
Many don't I know, but technically an inverter is a separately-derived power source, and the neutral there should be tied to earth as well. The problem is that most inverters also function in pass-through mode.
 
I hope that helps. Let me know what you find.
 
s/v Phantom Amel 54
 
 
On T hursday, December 3, 2015 7:42 AM, "karkauai@... [amelyachtowners]" <amelyachtowners@...> wrote:
 
 
Well, I have separated all the 220AC ground wires at the 220 box in the galley and at the 220 boxes in the engine room. I found that the output cable from the generator is grounded to the generator case, and thus, to the bonding system. The other end of that cable goes to the automatic switch that chooses generator over shore power, where it is connected to all other 220 grounds via the output from the switch.
This violates my understanding that the 220AC ground should NOT be connected to the bonding system. Now what????

Kent
SM243
Kristy
 




Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

James Wendell <ms42phantom54@...>
 

Wow, I have never seen that before.
Thanks



On Thursday, December 3, 2015 2:47 PM, "divanz620@... [amelyachtowners]" wrote:


 
There's a solenoid (relay) in the positive feed to the starter motor and also one in the negative feed. They both close when the start button is activated and for that brief time the battery negative is connected to the generator frame, when the generator starts and the start button is released, the realys open and the negative is isolated from the generator frame.
Its the same system on the main engine.
Cheers
Alan
Elyse SM437 



Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

Alan Leslie
 

There's a solenoid (relay) in the positive feed to the starter motor and also one in the negative feed. They both close when the start button is activated and for that brief time the battery negative is connected to the generator frame, when the generator starts and the start button is released, the realys open and the negative is isolated from the generator frame.
Its the same system on the main engine.
Cheers
Alan
Elyse SM437 


Re: [Amel Yacht Owners] Re: Engine Problems Amel 54

James Wendell <ms42phantom54@...>
 

No one could do a compression check, since the folks I have to deal with here do not have the Volvo test equipment needed. I would have had to buy it all or bring in some firm from another state.
Go figure that.

Also, no I did not take off the head. That is a lot of work and not worth the expense if I am planning a new engine at this point. There is no point throwing more investigation money at this engine. No one has been able to fix it or (with partial dis-assembly) absolutely identify the problem. Having completely ruled out the electrical and fuel systems (my good mechanic now demonstrated that they all are working correctly), the bottom line is that it is clearly not a simple problem. I concur with his assessment after I saw the salt crystals in the exhaust near the turbo
Thanks,
Jamie



On Thursday, December 3, 2015 1:27 PM, "Danny and Yvonne SIMMS simms@... [amelyachtowners]" wrote:


 
Hi Jamie,
what a nightmare you have had. We all feel for you. The valve and cylinder damage suspected would certainly affect the compression. Did you ever manage to get someone to do a full compression test.
Regards
Danny
SM 299 Ocean Pearl


From: "ms42phantom54@... [amelyachtowners]" <amelyachtowners@...>
To: amelyachtowners@...
Sent: Thursday, 3 December 2015 1:04 PM
Subject: Re: [Amel Yacht Owners] Re: Engine Problems Amel 54

 
Trevor, trust me I am well aware of the risks of cranking a no-start engine with sea water being drawn in. I was very careful to avoid water buildup in the muffler and exhaust at all times.

The engine would not start a week after it had run for 4 days, and that could not have been caused by excessive cranking. I did not try to start it in the interim, and when I did I carefully drained the muffler or shut off the raw water intake valve after a few attempts to get it going. And I kept draining it periodically as we tested and tested. If it had filled up with water during that time, the engine would have seized. I have seen engines do that before, and it is almost like having a dead battery. The engine will not even turn over. In my case here, the engine has always cranked just fine but never even coughed after the run up from Florida in June.

My service guy suggested that it could have been a long time in the making (possibly from weak compression) and it could have gotten worse during the trip up from Florida. I ran it fairly hard during the trip after the sea trial problems, which obviously would have increased exhaust back pressure and reduced the exhaust efficiency at higher RPM, especially if the engine compression was not up to par. He suggested, as well, that sitting for a week with any sort of "backwash" water (even heavy vapor if you will) could have caused it to fail. Again, short of tearing the engine down, he cannot say for sure. But we have ruled out every other possibility we can think of, including all those who have offered suggestions and lent support from the group. I am out of options now. There is nothing else to test or try.

I do not want to de-Amel my boat (I have been trying to keep to the design philosophy Henri set in place in all that I do), but I do need to ensure that water does not get into the engine in the future. If that means a bit of rework of the exhaust as I install my new engine, well then I need to do that for my boat. No one and no engineers are correct all the time. And, as you know, each boat is different in how it behaves. I have to deal with what I have. A new engine is expensive but clearly not an undesirable thing..............

Thanks for the support.
Jamie




 





Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

James Wendell <ms42phantom54@...>
 

Eric, I guess I don't understand what you mean. How does the negative get disconnected after the generator starts? It would have to be connected in advance to get the starter to even work. Most negatives go directly to the generator frame which is integral with the starter.
Can you help me here?
Jamie
s/v Phantom



On Thursday, December 3, 2015 1:06 PM, "sailormon kimberlite@... [amelyachtowners]" wrote:


 
Hi,
My generator has an isolated ground and the negative is not connected to the start battery except when the generator is starting.
Fair Winds
Eric
Kimberlite Amel Super Maramu #376
 
 
From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Thursday, December 03, 2015 9:41 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis
 
 
Kent, again thanks for the kind words about my engine failure on Phantom. Just to confirm my comments, I am not suggesting the exhaust design was necessarily at fault, but in my case the layout of the system certainly could have exacerbated my engine failure. In any event, if I can take steps to improve with my new engine, I will.
 
If I can comment on your AC findings, I understand that Amel deliberately does not connect the AC earth to the DC bonding grid. That, of course, is totally opposite from US regulations that mandate that connection for safety, a practice to which I fully subscribe as an electrical engineer. There is also the absolute "no-no" of connecting AC neutral to earth anywhere on the boat unless you have an isolation transformer.
 
The exception, however, is at a separately-derived power source. For a shore power connection, the neutral-to-earth bond would be at the shore power source in the marina. For a generator, it would be at the generator. When the automatic transfer switch (ATS) is in shore power mode, it ensures the neutral is connected only to the shore power feeder and not the boat. It also ensures the grounding systems are not interconnected, since the neutral is not connected to the boat systems. Further the generator case will be connected to earth, since the battery negative for the starter lands on the frame. When the ATS is switched to generator, the neutral "should" be tied to AC earth, since it "should" be bonded to PE at the generator. You should verify the connection between the blue neutral wire and the green/yellow PE. If it is connected you are safe; if not, and you had a fault in an AC circuit to earth, the neutral would not have a return path to its source and the AC current would try to find an alternate path - not good.
 
Many don't I know, but technically an inverter is a separately-derived power source, and the neutral there should be tied to earth as well. The problem is that most inverters also function in pass-through mode.
 
I hope that helps. Let me know what you find.
 
s/v Phantom Amel 54
 
 
On Thursday, December 3, 2015 7:42 AM, "karkauai@... [amelyachtowners]" <amelyachtowners@...> wrote:
 
 
Well, I have separated all the 220AC ground wires at the 220 box in the galley and at the 220 boxes in the engine room. I found that the output cable from the generator is grounded to the generator case, and thus, to the bonding system. The other end of that cable goes to the automatic switch that chooses generator over shore power, where it is connected to all other 220 grounds via the output from the switch.
This violates my understanding that the 220AC ground should NOT be connected to the bonding system. Now what????

Kent
SM243
Kristy
 



Re: [Amel Yacht Owners] Re: Engine Problems Amel 54

Danny and Yvonne SIMMS
 

Hi Jamie,
what a nightmare you have had. We all feel for you. The valve and cylinder damage suspected would certainly affect the compression. Did you ever manage to get someone to do a full compression test.
Regards
Danny
SM 299 Ocean Pearl



From: "ms42phantom54@... [amelyachtowners]"
To: amelyachtowners@...
Sent: Thursday, 3 December 2015 1:04 PM
Subject: Re: [Amel Yacht Owners] Re: Engine Problems Amel 54

 
Trevor, trust me I am well aware of the risks of cranking a no-start engine with sea water being drawn in. I was very careful to avoid water buildup in the muffler and exhaust at all times.

The engine would not start a week after it had run for 4 days, and that could not have been caused by excessive cranking. I did not try to start it in the interim, and when I did I carefully drained the muffler or shut off the raw water intake valve after a few attempts to get it going. And I kept draining it periodically as we tested and tested. If it had filled up with water during that time, the engine would have seized. I have seen engines do that before, and it is almost like having a dead battery. The engine will not even turn over. In my case here, the engine has always cranked just fine but never even coughed after the run up from Florida in June.

My service guy suggested that it could have been a long time in the making (possibly from weak compression) and it could have gotten worse during the trip up from Florida. I ran it fairly hard during the trip after the sea trial problems, which obviously would have increased exhaust back pressure and reduced the exhaust efficiency at higher RPM, especially if the engine compression was not up to par. He suggested, as well, that sitting for a week with any sort of "backwash" water (even heavy vapor if you will) could have caused it to fail. Again, short of tearing the engine down, he cannot say for sure. But we have ruled out every other possibility we can think of, including all those who have offered suggestions and lent support from the group. I am out of options now. There is nothing else to test or try.

I do not want to de-Amel my boat (I have been trying to keep to the design philosophy Henri set in place in all that I do), but I do need to ensure that water does not get into the engine in the future. If that means a bit of rework of the exhaust as I install my new engine, well then I need to do that for my boat. No one and no engineers are correct all the time. And, as you know, each boat is different in how it behaves. I have to deal with what I have. A new engine is expensive but clearly not an undesirable thing..............

Thanks for the support.
Jamie




 



Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

eric freedman
 

Hi,

My generator has an isolated ground and the negative is not connected to the start battery except when the generator is starting.

Fair Winds

Eric

Kimberlite Amel Super Maramu #376

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Thursday, December 03, 2015 9:41 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

 

 

Kent, again thanks for the kind words about my engine failure on Phantom. Just to confirm my comments, I am not suggesting the exhaust design was necessarily at fault, but in my case the layout of the system certainly could have exacerbated my engine failure. In any event, if I can take steps to improve with my new engine, I will.

 

If I can comment on your AC findings, I understand that Amel deliberately does not connect the AC earth to the DC bonding grid. That, of course, is totally opposite from US regulations that mandate that connection for safety, a practice to which I fully subscribe as an electrical engineer. There is also the absolute "no-no" of connecting AC neutral to earth anywhere on the boat unless you have an isolation transformer.

 

The exception, however, is at a separately-derived power source. For a shore power connection, the neutral-to-earth bond would be at the shore power source in the marina. For a generator, it would be at the generator. When the automatic transfer switch (ATS) is in shore power mode, it ensures the neutral is connected only to the shore power feeder and not the boat. It also ensures the grounding systems are not interconnected, since the neutral is not connected to the boat systems. Further the generator case will be connected to earth, since the battery negative for the starter lands on the frame. When the ATS is switched to generator, the neutral "should" be tied to AC earth, since it "should" be bonded to PE at the generator. You should verify the connection between the blue neutral wire and the green/yellow PE. If it is connected you are safe; if not, and you had a fault in an AC circuit to earth, the neutral would not have a return path to its source and the AC current would try to find an alternate path - not good.

 

Many don't I know, but technically an inverter is a separately-derived power source, and the neutral there should be tied to earth as well. The problem is that most inverters also function in pass-through mode.

 

I hope that helps. Let me know what you find.

 

s/v Phantom Amel 54

 

 

On Thursday, December 3, 2015 7:42 AM, "karkauai@... [amelyachtowners]" <amelyachtowners@...> wrote:

 

 

Well, I have separated all the 220AC ground wires at the 220 box in the galley and at the 220 boxes in the engine room. I found that the output cable from the generator is grounded to the generator case, and thus, to the bonding system. The other end of that cable goes to the automatic switch that chooses generator over shore power, where it is connected to all other 220 grounds via the output from the switch.
This violates my understanding that the 220AC ground should NOT be connected to the bonding system. Now what????

Kent
SM243
Kristy

 


Re: [Amel Yacht Owners] Re: Engine Problems Amel 54

eric freedman
 

Jamie,

Did you actually take the head off the engine and look at the cylinders and valves?

Fair Winds

Eric

Kimberlite Amel Super Maramu #376

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Thursday, December 03, 2015 9:27 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] Re: Engine Problems Amel 54

 

 

Jamie, Sorry you're having to deal with this but glad a solution is finally in sight. I don't know if the 54 engine and electrical system is ground-isolated like the SM, but if so, then as others will attest, make sure that your new engine installation and all of it's components, bolt-ons and accessories are ground-isolated too.
Jim
SM 384 Sirena Azul


Re: [Amel Yacht Owners] Re: Connecting B&G 2000 With Autohelm 7000

seafeverofcuan@...
 

Sorry Duane,
                   I only sent you half of the message. Press start and auto together and you should see "wind" appear on the display.
The autopilot did not come with this as standard, but you can easily reto fit the piece of software.
Trevor


Re: [Amel Yacht Owners] Re: Connecting B&G 2000 With Autohelm 7000

seafeverofcuan@...
 

Duane,
          Do you know if you have the wind steering option on Wanderer?

Trevor
Seafever
SM425
Mexico


Re: [Amel Yacht Owners] Re: Connecting B&G 2000 With Autohelm 7000

Andrew & Kate Lamb
 

As I recall there is a button on the autopilot control “WV” for wind vane then it steers a course relative to the wind and has already worked out the angle of the wind and what tack you are on. However I guess this may vary depending on what autopilot computer you have.

 

Andrew

 

 

Ronpische

SM2k 472

Canet en Roussillion, France

 

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Thursday, December 03, 2015 6:01 PM
To: amelyachtowners@...
Subject: [Amel Yacht Owners] Re: Connecting B&G 2000 With Autohelm 7000

 

 

Andrew,

How do you switch the Autohelm from compass to wind angle control?

Duane
Wanderer SM#477


Re: Connecting B&G 2000 With Autohelm 7000

Duane Siegfri
 

Andrew,

How do you switch the Autohelm from compass to wind angle control?

Duane
Wanderer SM#477


Re: [Amel Yacht Owners] Connecting B&G 2000 With Autohelm 7000

Ann-Sofie Svanberg <kanalmamman@...>
 

Hi Paul
We always sail on the wind angel. So it is possible.

Den kabeln som har NMEA vinddata kopplas till kontrollenheten i sittbrunnen och inte till kursdatorn. För detaljerad inkopplings instruktion se manualen.

/Ann-Sofie
@Lady Annila, SM232, 1998
Present in Licata, Sicilly.




Skickat från min iPad

3 dec. 2015 kl. 16:14 skrev osterberg.paul.l@... [amelyachtowners] <amelyachtowners@...>:

 

Hello!

Is it possible to connect the B&G NMEA out put with the NMEA input on the Autohelm 7000 to have it steer according to wind angle? if not is it anyone who have the Autohelm wind vane? is it a good alternative.

I think it's good to be able to steer according to wind angle during long passage especially at night


Paul on S/Y Kerpa SM#259




Re: [Amel Yacht Owners] Connecting B&G 2000 With Autohelm 7000

Andrew & Kate Lamb
 

Hi

 

That is one of the first things I did when we bought our boat and wondered why it had not been done as standard but it meant running a twisted pair of wires from the B&G display at the chart table to the autopilot controller. Works well.

 

Andrew

 

 

Ronpische

SM2k 472

Canet en Roussillion, France

 

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Thursday, December 03, 2015 4:14 PM
To: amelyachtowners@...
Subject: [Amel Yacht Owners] Connecting B&G 2000 With Autohelm 7000

 

 

Hello!

Is it possible to connect the B&G NMEA out put with the NMEA input on the Autohelm 7000 to have it steer according to wind angle? if not is it anyone who have the Autohelm wind vane? is it a good alternative.

I think it's good to be able to steer according to wind angle during long passage especially at night

 

Paul on S/Y Kerpa SM#259

 

 


Connecting B&G 2000 With Autohelm 7000

Paul Osterberg
 

Hello!

Is it possible to connect the B&G NMEA out put with the NMEA input on the Autohelm 7000 to have it steer according to wind angle? if not is it anyone who have the Autohelm wind vane? is it a good alternative.

I think it's good to be able to steer according to wind angle during long passage especially at night


Paul on S/Y Kerpa SM#259




Re: [Amel Yacht Owners] Re: Engine Problems Amel 54

James Wendell <ms42phantom54@...>
 

Jim, I not certain I understand what you mean by "ground-isolated?" The engine frame will be tied to DC earth of course through the battery DC negative feed to the starter, as well as through the alternator, unless I have an isolated alternator. That is not likely standard issue.

Can you clarify?
Thanks,
Jamie



On Thursday, December 3, 2015 9:26 AM, "capt.anderson@... [amelyachtowners]" wrote:


 
Jamie, Sorry you're having to deal with this but glad a solution is finally in sight. I don't know if the 54 engine and electrical system is ground-isolated like the SM, but if so, then as others will attest, make sure that your new engine installation and all of it's components, bolt-ons and accessories are ground-isolated too.
Jim
SM 384 Sirena Azul



Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

James Wendell <ms42phantom54@...>
 

Kent, again thanks for the kind words about my engine failure on Phantom. Just to confirm my comments, I am not suggesting the exhaust design was necessarily at fault, but in my case the layout of the system certainly could have exacerbated my engine failure. In any event, if I can take steps to improve with my new engine, I will.

If I can comment on your AC findings, I understand that Amel deliberately does not connect the AC earth to the DC bonding grid. That, of course, is totally opposite from US regulations that mandate that connection for safety, a practice to which I fully subscribe as an electrical engineer. There is also the absolute "no-no" of connecting AC neutral to earth anywhere on the boat unless you have an isolation transformer.

The exception, however, is at a separately-derived power source. For a shore power connection, the neutral-to-earth bond would be at the shore power source in the marina. For a generator, it would be at the generator. When the automatic transfer switch (ATS) is in shore power mode, it ensures the neutral is connected only to the shore power feeder and not the boat. It also ensures the grounding systems are not interconnected, since the neutral is not connected to the boat systems. Further the generator case will be connected to earth, since the battery negative for the starter lands on the frame. When the ATS is switched to generator, the neutral "should" be tied to AC earth, since it "should" be bonded to PE at the generator. You should verify the connection between the blue neutral wire and the green/yellow PE. If it is connected you are safe; if not, and you had a fault in an AC circuit to earth, the neutral would not have a return path to its source and the AC current would try to find an alternate path - not good.

Many don't I know, but technically an inverter is a separately-derived power source, and the neutral there should be tied to earth as well. The problem is that most inverters also function in pass-through mode.

I hope that helps. Let me know what you find.

s/v Phantom Amel 54



On Thursday, December 3, 2015 7:42 AM, "karkauai@... [amelyachtowners]" wrote:


 
Well, I have separated all the 220AC ground wires at the 220 box in the galley and at the 220 boxes in the engine room. I found that the output cable from the generator is grounded to the generator case, and thus, to the bonding system. The other end of that cable goes to the automatic switch that chooses generator over shore power, where it is connected to all other 220 grounds via the output from the switch.
This violates my understanding that the 220AC ground should NOT be connected to the bonding system. Now what????

Kent
SM243
Kristy



Re: [Amel Yacht Owners] Re: Engine Problems Amel 54

Jim Anderson
 

Jamie, Sorry you're having to deal with this but glad a solution is finally in sight. I don't know if the 54 engine and electrical system is ground-isolated like the SM, but if so, then as others will attest, make sure that your new engine installation and all of it's components, bolt-ons and accessories are ground-isolated too.
Jim
SM 384 Sirena Azul


Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis

karkauai
 

Well, I have separated all the 220AC ground wires at the 220 box in the galley and at the 220 boxes in the engine room. I found that the output cable from the generator is grounded to the generator case, and thus, to the bonding system. The other end of that cable goes to the automatic switch that chooses generator over shore power, where it is connected to all other 220 grounds via the output from the switch.
This violates my understanding that the 220AC ground should NOT be connected to the bonding system. Now what????

Kent
SM243
Kristy


Re: [Amel Yacht Owners] Re: Engine Problems Amel 54

karkauai
 

What a bummer!  My heart goes out to you, Jamie.

I've never heard of this happening on another Amel.  Has anyone else?  If not, it's hard to blame it on a design flaw.
Kent
SM 243
Kristy 


On Dec 2, 2015, at 7:04 PM, ms42phantom54@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Trevor, trust me I am well aware of the risks of cranking a no-start engine with sea water being drawn in. I was very careful to avoid water buildup in the muffler and exhaust at all times.


The engine would not start a week after it had run for 4 days, and that could not have been caused by excessive cranking. I did not try to start it in the interim, and when I did I carefully drained the muffler or shut off the raw water intake valve after a few attempts to get it going. And I kept draining it periodically as we tested and tested. If it had filled up with water during that time, the engine would have seized. I have seen engines do that before, and it is almost like having a dead battery. The engine will not even turn over. In my case here, the engine has always cranked just fine but never even coughed after the run up from Florida in June.

My service guy suggested that it could have been a long time in the making (possibly from weak compression) and it could have gotten worse during the trip up from Florida. I ran it fairly hard during the trip after the sea trial problems, which obviously would have increased exhaust back pressure and reduced the exhaust efficiency at higher RPM, especially if the engine compression was not up to par. He suggested, as well, that sitting for a week with any sort of "backwash" water (even heavy vapor if you will) could have caused it to fail. Again, short of tearing the engine down, he cannot say for sure. But we have ruled out every other possibility we can think of, including all those who have offered suggestions and lent support from the group. I am out of options now. There is nothing else to test or try.

I do not want to de-Amel my boat (I have been trying to keep to the design philosophy Henri set in place in all that I do), but I do need to ensure that water does not get into the engine in the future. If that means a bit of rework of the exhaust as I install my new engine, well then I need to do that for my boat. No one and no engineers are correct all the time. And, as you know, each boat is different in how it behaves. I have to deal with what I have. A new engine is expensive but clearly not an undesirable thing..............

Thanks for the support.
Jamie