[Amel Yacht Owners] engine cruising RPM


Kim Kimball <dhk@...>
 

Yeah.  Water injection would have been nice.  Our naturally aspirated 2-stroke diesels, running at constant speed of course, never carboned up.

But the turbos on the EMDs were a mistake in design.  Cummins too, though I don't think they were optional on those.  When I saw EMDs with blowers instead of turbos I cheered.  Although the number of turbo failures on my ships was blessedly small.

Kim


On 7/10/18 10:37 PM, carcodespam@... [amelyachtowners] wrote:
 
I have worked also many years as chief engineer on cargo ships. Main engines has often been 2-stroke Diesel with turbos. To clean the turbos they was feeded from time to time with a water injection. This temperature shock loosen the dirt and through it out. Another type of 2-stroke Diesel called Modag was used for generators and oiled like hell. It was common their eshaust pipe takes fire from the oil inside. When that happens they were idled and the exhaust was burned out at observed condition.
Boat Diesel are usually small 4-stroke engines with other behaviors. Most problems we have in Europe is the bad fuel. In Europe gasoil is mixed with 10 % biodiesel. Biodiesl-eating microbes blocks filters and tubes and leads to a brown-black thick coating and dirt in the tank.

Gerhard, Amel Sharki #60


carcodespam@...
 

I have worked also many years as chief engineer on cargo ships. Main engines has often been 2-stroke Diesel with turbos. To clean the turbos they was feeded from time to time with a water injection. This temperature shock loosen the dirt and through it out. Another type of 2-stroke Diesel called Modag was used for generators and oiled like hell. It was common their eshaust pipe takes fire from the oil inside. When that happens they were idled and the exhaust was burned out at observed condition.
Boat Diesel are usually small 4-stroke engines with other behaviors. Most problems we have in Europe is the bad fuel. In Europe gasoil is mixed with 10 % biodiesel. Biodiesl-eating microbes blocks filters and tubes and leads to a brown-black thick coating and dirt in the tank.

Gerhard, Amel Sharki #60


Kim Kimball <dhk@...>
 

As a chief engineer of a service vessel with > 10 diesel engines,  including train engines, our rule of thumb was to operate at the correct operating temperature for the engine in question. That should be available in the manufacturer's documentation for your engine.

That being said, our main engines often had turbos, and we often had a requirement to idle them for hours.

Removing and replacing a turbo was a royal PITA ... and low operating temperature (low RPM) causes both engines and turbos to accumulate carbon (valves, vanes ...)

I got good at  replacing cylinder heads (not equipped to swap out valves) and not so good at the occasional turbo replacement.

Operating temperature is your friend.  If, no matter what RPM you're running, you can't reach the operating temperature, the most common culprit is a thermostat.

Kim

On 7/9/18 12:34 PM, Ryan Meador ryan.d.meador@gmail.com [amelyachtowners] wrote:
Thank you all for the info.  As I predicted going in, there is no simple answer.  But I think I have some guides now.

Ryan and Kelly
SM 233 Iteration
Boston, MA, USA



On Sun, Jul 8, 2018 at 4:06 PM Courtney Gorman Itsfun1@aol.com <mailto:Itsfun1@aol.com> [amelyachtowners] <amelyachtowners@yahoogroups.com <mailto:amelyachtowners@yahoogroups.com>> wrote:

Amen Porter well said

Sent from my iPhone

On Jul 8, 2018, at 12:41 PM, Porter McRoberts
portermcroberts@yahoo.com <mailto:portermcroberts@yahoo.com>
[amelyachtowners] <amelyachtowners@yahoogroups.com
<mailto:amelyachtowners@yahoogroups.com>> wrote:

Teun,

Mostly true. New long block 800 hours ago and New injectors about
400 hours ago.
It is a common rail.
On a different topic. We’re currently stuck in panama with a bad
boost pressure sensor.
I have envy of anyone who can unplug the computer and have the
engine run.
The concept that a computer controlled engine be installed in a
world cruising sailboat seems antithetical to the purpose of a
sailboat, and to ours in particular.
I’ve been training (at your knees, and especially Bill R’s) for
the past year to be as self sufficient as possible, and to be
thwarted by a stray electron underscores how vulnerable we are.
Our cruising buddies are on a 1984 trintella. Sailed from
Croatia. They are in year #5. Old Perkins runs like a boss. I
asked my buddy, who is in his own right a Jedi of machinery, how
often he changes his fuel filters.  He chuckled.  “I don’t think
I’ve needed to do that” he said. Pressure’s good. Engine runs well.
I had engine envy. Not that the Volvo isn’t a fine piece of
hardware, but.... it’s the intersection of important and
complicated. Not a good combo. Like I say. Thank God for sails,
and the fact that we sailors got around just fine for the first
1000 years without motors.

In short. Seems like diesels (or the industry and associated
standards) took a step back in the past 15 years putting
efficiency over simplicity. I think Nigel Calder would agree.

Have wonderful Sundays. Without this motor glitch we wouldn’t
have seen the incredibly beautiful town of El Valle up here in
the Panamanian cordillera.

Porter, Helen and crew
S/V Ibis
54-152
Panama City


Sent from my iPad

On Jul 7, 2018, at 6:30 PM, Teun BAAS teun@amelit.net
<mailto:teun@amelit.net> [amelyachtowners]
<amelyachtowners@yahoogroups.com
<mailto:amelyachtowners@yahoogroups.com>> wrote:

Hi Porter,

I understood you had a new VOLVO installed. If so, *and it is a
common rail*, then there is *NO* need to run the engine on high
rpms to “burn out the soot”.

This is the specific instruction I got this week from the SYDNEY
VOLVO technician installing my VOLVO D3 110 H here in NOUMEA NEW
CALEDONIA.

Best Regards Teun

AMELIT  54 – 128

NOUMEA NEW CALEDONIA

Jul 08, 2018 10:27:44

*From:* amelyachtowners@yahoogroups.com
<mailto:amelyachtowners@yahoogroups.com>
[mailto:amelyachtowners@yahoogroups.com]
*Sent:* Sunday, July 08, 2018 10:24 AM
*To:* amelyachtowners@yahoogroups.com
<mailto:amelyachtowners@yahoogroups.com>
*Subject:* Re: [Amel Yacht Owners] engine cruising RPM

Thanks Mark.

If temp is the final data point, we cruise at about 79-80. What
should be the goal?

Thanks again!

Porter

Sent from my iPad


On Jul 7, 2018, at 11:13 AM, 'Mark Erdos' mcerdos@gmail.com
<mailto:mcerdos@gmail..com> [amelyachtowners]
<amelyachtowners@yahoogroups.com
<mailto:amelyachtowners@yahoogroups.com>> wrote:

Porter,

It really doesn’t matter how you do it but you need to
create internal engine heat to clean out the engine. This is
done with a load on the engine. If in neutral, it will take
longer to create a load and heat. In gear while underway
will heat up the engine faster.

This is true for all diesel engines.

Where you run the RPM depends on the engine. Typically, 80%
of max power will heat up the engine nicely without too much
strain. This is also good for the turbocharger, if fitted
with one.

How long? At least every couple of hours while underway, if
not a little more frequently... We run ours up every hour
for about five minutes. This works for us.

Keep in mind, this is not just the ship’s engine but also
true for the genset. Running a genset without load will
cause carbon buildup. Keep the genset loaded when charging
batteries etc. We find it best to run a couple of AC units
or do a load of laundry etc. The battery charger only puts
load on the genset at the beginning of the charge cycle.

Hope this helps.

With best regards,

Mark

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us <http://www.creampuff.us>

*From:*amelyachtowners@yahoogroups.com
<mailto:amelyachtowners@yahoogroups.com>
[mailto:amelyachtowners@yahoogroups.com]
*Sent:* Saturday, July 7, 2018 11:35 AM
*To:* amelyachtowners@yahoogroups.com
<mailto:amelyachtowners@yahoogroups.com>
*Subject:* Re: [Amel Yacht Owners] engine cruising RPM

Ok. Bullshit aside.

I do have a few real questions, that I’ve had for a while.

It’s the same for all diesels. Yes?

Is “racing” out of gear best? I would think load would be
required to increase fuel consumption and thus heat. Fuel
burn>>heat dissipation 2/2 raw water flow.

Forget the rpm. Where is the throttle?  100% down? 80%?

And for how long?

Many thanks, as always to this great group.

Porter

A54-152.

Excuse the errors.

Sent from my IPhone

Www.fouribis.com <http://Www.fouribis.com>


On Jul 7, 2018, at 9:02 AM, 'Mark Erdos' mcerdos@gmail.com
<mailto:mcerdos@gmail.com> [amelyachtowners]
<amelyachtowners@yahoogroups.com
<mailto:amelyachtowners@yahoogroups.com>> wrote:

Bob,

Wow! Sorry. I didn’t realize I had to be so freaking
specific. Seriously! The essence of the post I made is
100% correct. I didn’t intend to make a verbatim quote
of the manual. If  I had, I would have used quotation
marks. I stated this is OUTLINED in the manual. I did
not say this is a DIRECT QUOTE from the manual. Geeez!
And, please note I did say 4JH4 manual, not 4JH3 as you
are quoting.

But if you want specific details of the JH4 Operation
Manual, publication number OAJH4-G00102, page 78. I
quote, “Periodically operate the engine near maximum
speed while underway. This will generate higher exhaust
temperatures, which help clean out hard carbon deposits,
maintain engine performance and prolong the life of the
engine”

This is below the section you quote about running it in
idle and speaks specifically about running the engine
_while underway_.

Regardless of whether this is done in neutral or in gear
while underway, the purpose of the procedure is to raise
the internal temperature of the engine periodically to
remove carbon build up. Carbon build up will kill a
diesel engine.

I’m feelin’ a little crabby today. Can you tell?

With best regards,

Mark

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us <http://www.creampuff.us>

*From:*amelyachtowners@yahoogroups.com
<mailto:amelyachtowners@yahoogroups.com>
[mailto:amelyachtowners@yahoogroups.com]
*Sent:* Saturday, July 7, 2018 3:20 AM
*To:* amelyachtowners@yahoogroups.com
<mailto:amelyachtowners@yahoogroups.com>
*Subject:* RE: [Amel Yacht Owners] engine cruising RPM

Hi Mark,

Regarding "Running a lower RPMs without load will
shorten the life of the engine unless it is pushed up at
least once per hour for about 5 minutes. This is
outlinede in the Yanmar operation manual."

This is not to challenge the veracity of your statement
but I cannot find that in my Yanmar manual. Maybe you
have a different manual and it would be helpful (really)
to have you quote what it says.

What my 4JH3-HTE Operation Manual says (on page 30
section 4.6) is:

"When operating the engine at low speed ffor long
periods of time, race the engine once every 2
hours"..."Racing the Engine, Morse Remote Control Handle
Pull out the handle lever...and shift the engine speed
from high to low several times...Racing the engine
removes carbon built up in the compustion chamber around
the fuel injection valve. Neglecting to race tthe engine
will cause the exhaust to turn black and lower the
efficiency of the engine".

In other words it says to gun the engine several times
while it is in neutral.

Like others, we vary my speed between 1600 and 2200 for
cruising and can cruise up to 2400 rpm. We also run it
at say 2800 for 5 minutes or so periodically. However, I
cannot find where Yanmar recommends this.  There are
postings in this group (not yours) that say to run it
full out for 5 minutes, even full out fo 30 minutes but
I don't think that is advisable. Seems that vibration is
higher and it might be hard on the transmission and c
drive as well.  Like most of us we vary the speed and
run it harder at times but we also do the "Racing"
procedure that is in our manual.

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna


Ryan Meador
 

Thank you all for the info.  As I predicted going in, there is no simple answer.  But I think I have some guides now.

Ryan and Kelly
SM 233 Iteration
Boston, MA, USA



On Sun, Jul 8, 2018 at 4:06 PM Courtney Gorman Itsfun1@... [amelyachtowners] <amelyachtowners@...> wrote:
 

Amen Porter well said 


On Jul 8, 2018, at 12:41 PM, Porter McRoberts portermcroberts@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Teun,

Mostly true. New long block 800 hours ago and New injectors about 400 hours ago. 
It is a common rail. 
On a different topic. We’re currently stuck in panama with a bad boost pressure sensor. 
I have envy of anyone who can unplug the computer and have the engine run. 
The concept that a computer controlled engine be installed in a world cruising sailboat seems antithetical to the purpose of a sailboat, and to ours in particular. 
I’ve been training (at your knees, and especially Bill R’s) for the past year to be as self sufficient as possible, and to be thwarted by a stray electron underscores how vulnerable we are. Our cruising buddies are on a 1984 trintella. Sailed from Croatia. They are in year #5. Old Perkins runs like a boss. I asked my buddy, who is in his own right a Jedi of machinery, how often he changes his fuel filters.  He chuckled.  “I don’t think I’ve needed to do that” he said. Pressure’s good. Engine runs well. 
I had engine envy. Not that the Volvo isn’t a fine piece of hardware, but.... it’s the intersection of important and complicated. Not a good combo. Like I say. Thank God for sails, and the fact that we sailors got around just fine for the first 1000 years without motors. 

In short. Seems like diesels (or the industry and associated standards) took a step back in the past 15 years putting efficiency over simplicity. I think Nigel Calder would agree. 

Have wonderful Sundays. Without this motor glitch we wouldn’t have seen the incredibly beautiful town of El Valle up here in the Panamanian cordillera. 

Porter, Helen and crew
S/V Ibis
54-152
Panama City



On Jul 7, 2018, at 6:30 PM, Teun BAAS teun@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Hi Porter,

 

I understood you had a new VOLVO installed. If so, and it is a common rail, then there is NO need to run the engine on high rpms to “burn out the soot”.

 

This is the specific instruction I got this week from the SYDNEY VOLVO technician installing my VOLVO D3 110 H here in NOUMEA NEW CALEDONIA.

 

Best Regards Teun

AMELIT  54 – 128

NOUMEA NEW CALEDONIA

Jul 08, 2018   10:27:44

 

 

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Sunday, July 08, 2018 10:24 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Thanks Mark. 

If temp is the final data point, we cruise at about 79-80. What should be the goal?

Thanks again!

Porter


On Jul 7, 2018, at 11:13 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Porter,

 

It really doesn’t matter how you do it but you need to create internal engine heat to clean out the engine. This is done with a load on the engine. If in neutral, it will take longer to create a load and heat. In gear while underway will heat up the engine faster.

 

This is true for all diesel engines.

 

Where you run the RPM depends on the engine. Typically, 80% of max power will heat up the engine nicely without too much strain. This is also good for the turbocharger, if fitted with one.

 

How long? At least every couple of hours while underway, if not a little more frequently... We run ours up every hour for about five minutes. This works for us.

 

Keep in mind, this is not just the ship’s engine but also true for the genset. Running a genset without load will cause carbon buildup. Keep the genset loaded when charging batteries etc. We find it best to run a couple of AC units or do a load of laundry etc. The battery charger only puts load on the genset at the beginning of the charge cycle.

 

Hope this helps.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 11:35 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Ok. Bullshit aside. 

I do have a few real questions, that I’ve had for a while. 

It’s the same for all diesels. Yes?  

Is “racing” out of gear best?  I would think load would be required to increase fuel consumption and thus heat. Fuel burn>>heat dissipation 2/2 raw water flow. 

Forget the rpm. Where is the throttle?  100% down? 80%?  

And for how long?  

 

Many thanks, as always to this great group. 

 

Porter

A54-152. 

 

 

Excuse the errors.  

Sent from my IPhone 


On Jul 7, 2018, at 9:02 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Bob,

 

Wow! Sorry. I didn’t realize I had to be so freaking specific. Seriously! The essence of the post I made is 100% correct. I didn’t intend to make a verbatim quote of the manual. If  I had, I would have used quotation marks. I stated this is OUTLINED in the manual. I did not say this is a DIRECT QUOTE from the manual. Geeez! And, please note I did say 4JH4 manual, not 4JH3 as you are quoting.

 

But if you want specific details of the JH4 Operation Manual, publication number OAJH4-G00102, page 78. I quote, “Periodically operate the engine near maximum speed while underway. This will generate higher exhaust temperatures, which help clean out hard carbon deposits, maintain engine performance and prolong the life of the engine”

This is below the section you quote about running it in idle and speaks specifically about running the engine while underway.

 

Regardless of whether this is done in neutral or in gear while underway, the purpose of the procedure is to raise the internal temperature of the engine periodically to remove carbon build up. Carbon build up will kill a diesel engine.

 

I’m feelin’ a little crabby today. Can you tell?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 3:20 AM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM

 

 

Hi Mark,

Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

 

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

 

In other words it says to gun the engine several times while it is in neutral.

 

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

 

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna

 

 


Courtney Gorman
 

Amen Porter well said 


On Jul 8, 2018, at 12:41 PM, Porter McRoberts portermcroberts@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Teun,

Mostly true. New long block 800 hours ago and New injectors about 400 hours ago. 
It is a common rail. 
On a different topic. We’re currently stuck in panama with a bad boost pressure sensor. 
I have envy of anyone who can unplug the computer and have the engine run. 
The concept that a computer controlled engine be installed in a world cruising sailboat seems antithetical to the purpose of a sailboat, and to ours in particular. 
I’ve been training (at your knees, and especially Bill R’s) for the past year to be as self sufficient as possible, and to be thwarted by a stray electron underscores how vulnerable we are. Our cruising buddies are on a 1984 trintella. Sailed from Croatia. They are in year #5. Old Perkins runs like a boss. I asked my buddy, who is in his own right a Jedi of machinery, how often he changes his fuel filters.  He chuckled.  “I don’t think I’ve needed to do that” he said. Pressure’s good. Engine runs well. 
I had engine envy. Not that the Volvo isn’t a fine piece of hardware, but.... it’s the intersection of important and complicated. Not a good combo. Like I say. Thank God for sails, and the fact that we sailors got around just fine for the first 1000 years without motors. 

In short. Seems like diesels (or the industry and associated standards) took a step back in the past 15 years putting efficiency over simplicity. I think Nigel Calder would agree. 

Have wonderful Sundays. Without this motor glitch we wouldn’t have seen the incredibly beautiful town of El Valle up here in the Panamanian cordillera. 

Porter, Helen and crew
S/V Ibis
54-152
Panama City



On Jul 7, 2018, at 6:30 PM, Teun BAAS teun@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Hi Porter,

 

I understood you had a new VOLVO installed. If so, and it is a common rail, then there is NO need to run the engine on high rpms to “burn out the soot”.

 

This is the specific instruction I got this week from the SYDNEY VOLVO technician installing my VOLVO D3 110 H here in NOUMEA NEW CALEDONIA.

 

Best Regards Teun

AMELIT  54 – 128

NOUMEA NEW CALEDONIA

Jul 08, 2018   10:27:44

 

 

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Sunday, July 08, 2018 10:24 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Thanks Mark. 

If temp is the final data point, we cruise at about 79-80. What should be the goal?

Thanks again!

Porter


On Jul 7, 2018, at 11:13 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Porter,

 

It really doesn’t matter how you do it but you need to create internal engine heat to clean out the engine. This is done with a load on the engine. If in neutral, it will take longer to create a load and heat. In gear while underway will heat up the engine faster.

 

This is true for all diesel engines.

 

Where you run the RPM depends on the engine. Typically, 80% of max power will heat up the engine nicely without too much strain. This is also good for the turbocharger, if fitted with one.

 

How long? At least every couple of hours while underway, if not a little more frequently... We run ours up every hour for about five minutes. This works for us.

 

Keep in mind, this is not just the ship’s engine but also true for the genset. Running a genset without load will cause carbon buildup. Keep the genset loaded when charging batteries etc. We find it best to run a couple of AC units or do a load of laundry etc. The battery charger only puts load on the genset at the beginning of the charge cycle.

 

Hope this helps.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 11:35 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Ok. Bullshit aside. 

I do have a few real questions, that I’ve had for a while. 

It’s the same for all diesels. Yes?  

Is “racing” out of gear best?  I would think load would be required to increase fuel consumption and thus heat. Fuel burn>>heat dissipation 2/2 raw water flow. 

Forget the rpm. Where is the throttle?  100% down? 80%?  

And for how long?  

 

Many thanks, as always to this great group. 

 

Porter

A54-152. 

 

 

Excuse the errors.  

Sent from my IPhone 


On Jul 7, 2018, at 9:02 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Bob,

 

Wow! Sorry. I didn’t realize I had to be so freaking specific. Seriously! The essence of the post I made is 100% correct. I didn’t intend to make a verbatim quote of the manual. If  I had, I would have used quotation marks. I stated this is OUTLINED in the manual. I did not say this is a DIRECT QUOTE from the manual. Geeez! And, please note I did say 4JH4 manual, not 4JH3 as you are quoting.

 

But if you want specific details of the JH4 Operation Manual, publication number OAJH4-G00102, page 78. I quote, “Periodically operate the engine near maximum speed while underway. This will generate higher exhaust temperatures, which help clean out hard carbon deposits, maintain engine performance and prolong the life of the engine”

This is below the section you quote about running it in idle and speaks specifically about running the engine while underway.

 

Regardless of whether this is done in neutral or in gear while underway, the purpose of the procedure is to raise the internal temperature of the engine periodically to remove carbon build up. Carbon build up will kill a diesel engine.

 

I’m feelin’ a little crabby today. Can you tell?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 3:20 AM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM

 

 

Hi Mark,

Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

 

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

 

In other words it says to gun the engine several times while it is in neutral.

 

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

 

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna

 

 


Porter McRoberts
 

Teun,
Mostly true. New long block 800 hours ago and New injectors about 400 hours ago. 
It is a common rail. 
On a different topic. We’re currently stuck in panama with a bad boost pressure sensor. 
I have envy of anyone who can unplug the computer and have the engine run. 
The concept that a computer controlled engine be installed in a world cruising sailboat seems antithetical to the purpose of a sailboat, and to ours in particular. 
I’ve been training (at your knees, and especially Bill R’s) for the past year to be as self sufficient as possible, and to be thwarted by a stray electron underscores how vulnerable we are. Our cruising buddies are on a 1984 trintella. Sailed from Croatia. They are in year #5. Old Perkins runs like a boss. I asked my buddy, who is in his own right a Jedi of machinery, how often he changes his fuel filters.  He chuckled.  “I don’t think I’ve needed to do that” he said. Pressure’s good. Engine runs well. 
I had engine envy. Not that the Volvo isn’t a fine piece of hardware, but.... it’s the intersection of important and complicated. Not a good combo. Like I say. Thank God for sails, and the fact that we sailors got around just fine for the first 1000 years without motors. 

In short. Seems like diesels (or the industry and associated standards) took a step back in the past 15 years putting efficiency over simplicity. I think Nigel Calder would agree. 

Have wonderful Sundays. Without this motor glitch we wouldn’t have seen the incredibly beautiful town of El Valle up here in the Panamanian cordillera. 

Porter, Helen and crew
S/V Ibis
54-152
Panama City



On Jul 7, 2018, at 6:30 PM, Teun BAAS teun@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Hi Porter,

 

I understood you had a new VOLVO installed. If so, and it is a common rail, then there is NO need to run the engine on high rpms to “burn out the soot”.

 

This is the specific instruction I got this week from the SYDNEY VOLVO technician installing my VOLVO D3 110 H here in NOUMEA NEW CALEDONIA.

 

Best Regards Teun

AMELIT  54 – 128

NOUMEA NEW CALEDONIA

Jul 08, 2018   10:27:44

 

 

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Sunday, July 08, 2018 10:24 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Thanks Mark. 

If temp is the final data point, we cruise at about 79-80. What should be the goal?

Thanks again!

Porter


On Jul 7, 2018, at 11:13 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Porter,

 

It really doesn’t matter how you do it but you need to create internal engine heat to clean out the engine. This is done with a load on the engine. If in neutral, it will take longer to create a load and heat. In gear while underway will heat up the engine faster.

 

This is true for all diesel engines.

 

Where you run the RPM depends on the engine. Typically, 80% of max power will heat up the engine nicely without too much strain. This is also good for the turbocharger, if fitted with one.

 

How long? At least every couple of hours while underway, if not a little more frequently... We run ours up every hour for about five minutes. This works for us.

 

Keep in mind, this is not just the ship’s engine but also true for the genset. Running a genset without load will cause carbon buildup. Keep the genset loaded when charging batteries etc. We find it best to run a couple of AC units or do a load of laundry etc. The battery charger only puts load on the genset at the beginning of the charge cycle.

 

Hope this helps.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 11:35 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Ok. Bullshit aside. 

I do have a few real questions, that I’ve had for a while. 

It’s the same for all diesels. Yes?  

Is “racing” out of gear best?  I would think load would be required to increase fuel consumption and thus heat. Fuel burn>>heat dissipation 2/2 raw water flow. 

Forget the rpm. Where is the throttle?  100% down? 80%?  

And for how long?  

 

Many thanks, as always to this great group. 

 

Porter

A54-152. 

 

 

Excuse the errors.  

Sent from my IPhone 


On Jul 7, 2018, at 9:02 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Bob,

 

Wow! Sorry. I didn’t realize I had to be so freaking specific. Seriously! The essence of the post I made is 100% correct. I didn’t intend to make a verbatim quote of the manual. If  I had, I would have used quotation marks. I stated this is OUTLINED in the manual. I did not say this is a DIRECT QUOTE from the manual. Geeez! And, please note I did say 4JH4 manual, not 4JH3 as you are quoting.

 

But if you want specific details of the JH4 Operation Manual, publication number OAJH4-G00102, page 78. I quote, “Periodically operate the engine near maximum speed while underway. This will generate higher exhaust temperatures, which help clean out hard carbon deposits, maintain engine performance and prolong the life of the engine”

This is below the section you quote about running it in idle and speaks specifically about running the engine while underway.

 

Regardless of whether this is done in neutral or in gear while underway, the purpose of the procedure is to raise the internal temperature of the engine periodically to remove carbon build up. Carbon build up will kill a diesel engine.

 

I’m feelin’ a little crabby today. Can you tell?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 3:20 AM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM

 

 

Hi Mark,

Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

 

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

 

In other words it says to gun the engine several times while it is in neutral.

 

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

 

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna

 

 


Mark Erdos
 

Porter,

 

I think you need to look in the manual for the correct temperature range of the engine. It should give you a range in the specs section. You will want to run at the high end of the range for a few minutes.

 

My 4jh4 tops out at 87°C or about 190°F. At lower RPMs it runs just below 82°C or about 180°F

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 7:24 PM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Thanks Mark. 

If temp is the final data point, we cruise at about 79-80. What should be the goal?

Thanks again!

Porter


On Jul 7, 2018, at 11:13 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Porter,

 

It really doesn’t matter how you do it but you need to create internal engine heat to clean out the engine. This is done with a load on the engine. If in neutral, it will take longer to create a load and heat. In gear while underway will heat up the engine faster.

 

This is true for all diesel engines.

 

Where you run the RPM depends on the engine. Typically, 80% of max power will heat up the engine nicely without too much strain. This is also good for the turbocharger, if fitted with one.

 

How long? At least every couple of hours while underway, if not a little more frequently... We run ours up every hour for about five minutes. This works for us.

 

Keep in mind, this is not just the ship’s engine but also true for the genset. Running a genset without load will cause carbon buildup. Keep the genset loaded when charging batteries etc. We find it best to run a couple of AC units or do a load of laundry etc. The battery charger only puts load on the genset at the beginning of the charge cycle.

 

Hope this helps.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 11:35 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Ok. Bullshit aside. 

I do have a few real questions, that I’ve had for a while. 

It’s the same for all diesels. Yes?  

Is “racing” out of gear best?  I would think load would be required to increase fuel consumption and thus heat. Fuel burn>>heat dissipation 2/2 raw water flow. 

Forget the rpm. Where is the throttle?  100% down? 80%?  

And for how long?  

 

Many thanks, as always to this great group. 

 

Porter

A54-152. 

 

 

Excuse the errors.  

Sent from my IPhone 


On Jul 7, 2018, at 9:02 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Bob,

 

Wow! Sorry. I didn’t realize I had to be so freaking specific. Seriously! The essence of the post I made is 100% correct. I didn’t intend to make a verbatim quote of the manual. If  I had, I would have used quotation marks. I stated this is OUTLINED in the manual. I did not say this is a DIRECT QUOTE from the manual. Geeez! And, please note I did say 4JH4 manual, not 4JH3 as you are quoting.

 

But if you want specific details of the JH4 Operation Manual, publication number OAJH4-G00102, page 78. I quote, “Periodically operate the engine near maximum speed while underway. This will generate higher exhaust temperatures, which help clean out hard carbon deposits, maintain engine performance and prolong the life of the engine”

This is below the section you quote about running it in idle and speaks specifically about running the engine while underway.

 

Regardless of whether this is done in neutral or in gear while underway, the purpose of the procedure is to raise the internal temperature of the engine periodically to remove carbon build up. Carbon build up will kill a diesel engine.

 

I’m feelin’ a little crabby today. Can you tell?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 3:20 AM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM

 

 

Hi Mark,

Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

 

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

 

In other words it says to gun the engine several times while it is in neutral.

 

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

 

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna

 

 


Mark Erdos
 

Teun,

 

Common rail engines have been around for years and while they offer lower emissions and soot from the exhaust they are not the cure-all. The thing to remember here is all marine diesel engines are engines designed for land adapted to a marine application. No diesel engine is designed to run at 25% power for days on end. If a land based application called for only 25 hp then a 25 hp engine would be used, not a 110 hp engine. It is my opinion the even the most modern newest technologically advanced diesel engine still has emission issues (soot and carbon buildup) at low end rpms. Look at the recent history of VW and how they adjusted the software of the engine to trick the emissions computers. They did this because their latest efforts at design and massive expenditure failed to produce a clean burning diesel engine.

 

So, the question I have for you is, what does it hurt to push up the RPM once in a while? If the engine is designed to run at x RPM then it should be able to run at 80% of x rpm for at least five minutes per hour, should it not?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 7:30 PM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM
Importance: High

 

 

Hi Porter,

 

I understood you had a new VOLVO installed. If so, and it is a common rail, then there is NO need to run the engine on high rpms to “burn out the soot”.

 

This is the specific instruction I got this week from the SYDNEY VOLVO technician installing my VOLVO D3 110 H here in NOUMEA NEW CALEDONIA.

 

Best Regards Teun

AMELIT  54 – 128

NOUMEA NEW CALEDONIA

Jul 08, 2018   10:27:44

 

 

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Sunday, July 08, 2018 10:24 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Thanks Mark. 

If temp is the final data point, we cruise at about 79-80. What should be the goal?

Thanks again!

Porter

Sent from my iPad


On Jul 7, 2018, at 11:13 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Porter,

 

It really doesn’t matter how you do it but you need to create internal engine heat to clean out the engine. This is done with a load on the engine. If in neutral, it will take longer to create a load and heat. In gear while underway will heat up the engine faster.

 

This is true for all diesel engines.

 

Where you run the RPM depends on the engine. Typically, 80% of max power will heat up the engine nicely without too much strain. This is also good for the turbocharger, if fitted with one.

 

How long? At least every couple of hours while underway, if not a little more frequently... We run ours up every hour for about five minutes. This works for us.

 

Keep in mind, this is not just the ship’s engine but also true for the genset. Running a genset without load will cause carbon buildup. Keep the genset loaded when charging batteries etc. We find it best to run a couple of AC units or do a load of laundry etc. The battery charger only puts load on the genset at the beginning of the charge cycle.

 

Hope this helps.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 11:35 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Ok. Bullshit aside. 

I do have a few real questions, that I’ve had for a while. 

It’s the same for all diesels. Yes?  

Is “racing” out of gear best?  I would think load would be required to increase fuel consumption and thus heat. Fuel burn>>heat dissipation 2/2 raw water flow. 

Forget the rpm. Where is the throttle?  100% down? 80%?  

And for how long?  

 

Many thanks, as always to this great group. 

 

Porter

A54-152. 

 

 

Excuse the errors.  

Sent from my IPhone 


On Jul 7, 2018, at 9:02 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Bob,

 

Wow! Sorry. I didn’t realize I had to be so freaking specific. Seriously! The essence of the post I made is 100% correct. I didn’t intend to make a verbatim quote of the manual. If  I had, I would have used quotation marks. I stated this is OUTLINED in the manual. I did not say this is a DIRECT QUOTE from the manual. Geeez! And, please note I did say 4JH4 manual, not 4JH3 as you are quoting.

 

But if you want specific details of the JH4 Operation Manual, publication number OAJH4-G00102, page 78. I quote, “Periodically operate the engine near maximum speed while underway. This will generate higher exhaust temperatures, which help clean out hard carbon deposits, maintain engine performance and prolong the life of the engine”

This is below the section you quote about running it in idle and speaks specifically about running the engine while underway.

 

Regardless of whether this is done in neutral or in gear while underway, the purpose of the procedure is to raise the internal temperature of the engine periodically to remove carbon build up. Carbon build up will kill a diesel engine.

 

I’m feelin’ a little crabby today. Can you tell?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 3:20 AM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM

 

 

Hi Mark,

Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

 

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

 

In other words it says to gun the engine several times while it is in neutral.

 

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

 

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna

 

 


rossirossix4
 

Thanks Mark,
Good to know, just couldn't find it in our manual so I do appreciate the citation from the other Yanmar manual.  Based on that I think I feel better about operating at higher speeds periodically--we max out at about 3300 rpm.

Bob KAIMI SM#429


Teun BAAS
 

Hi Porter,

 

I understood you had a new VOLVO installed. If so, and it is a common rail, then there is NO need to run the engine on high rpms to “burn out the soot”.

 

This is the specific instruction I got this week from the SYDNEY VOLVO technician installing my VOLVO D3 110 H here in NOUMEA NEW CALEDONIA.

 

Best Regards Teun

AMELIT  54 – 128

NOUMEA NEW CALEDONIA

Jul 08, 2018   10:27:44

 

 

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Sunday, July 08, 2018 10:24 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Thanks Mark. 

If temp is the final data point, we cruise at about 79-80. What should be the goal?

Thanks again!

Porter


On Jul 7, 2018, at 11:13 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Porter,

 

It really doesn’t matter how you do it but you need to create internal engine heat to clean out the engine. This is done with a load on the engine. If in neutral, it will take longer to create a load and heat. In gear while underway will heat up the engine faster.

 

This is true for all diesel engines.

 

Where you run the RPM depends on the engine. Typically, 80% of max power will heat up the engine nicely without too much strain. This is also good for the turbocharger, if fitted with one.

 

How long? At least every couple of hours while underway, if not a little more frequently... We run ours up every hour for about five minutes. This works for us.

 

Keep in mind, this is not just the ship’s engine but also true for the genset. Running a genset without load will cause carbon buildup. Keep the genset loaded when charging batteries etc. We find it best to run a couple of AC units or do a load of laundry etc. The battery charger only puts load on the genset at the beginning of the charge cycle.

 

Hope this helps.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 11:35 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Ok. Bullshit aside. 

I do have a few real questions, that I’ve had for a while. 

It’s the same for all diesels. Yes?  

Is “racing” out of gear best?  I would think load would be required to increase fuel consumption and thus heat. Fuel burn>>heat dissipation 2/2 raw water flow. 

Forget the rpm. Where is the throttle?  100% down? 80%?  

And for how long?  

 

Many thanks, as always to this great group. 

 

Porter

A54-152. 

 

 

Excuse the errors.  

Sent from my IPhone 


On Jul 7, 2018, at 9:02 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Bob,

 

Wow! Sorry. I didn’t realize I had to be so freaking specific. Seriously! The essence of the post I made is 100% correct. I didn’t intend to make a verbatim quote of the manual. If  I had, I would have used quotation marks. I stated this is OUTLINED in the manual. I did not say this is a DIRECT QUOTE from the manual. Geeez! And, please note I did say 4JH4 manual, not 4JH3 as you are quoting.

 

But if you want specific details of the JH4 Operation Manual, publication number OAJH4-G00102, page 78. I quote, “Periodically operate the engine near maximum speed while underway. This will generate higher exhaust temperatures, which help clean out hard carbon deposits, maintain engine performance and prolong the life of the engine”

This is below the section you quote about running it in idle and speaks specifically about running the engine while underway.

 

Regardless of whether this is done in neutral or in gear while underway, the purpose of the procedure is to raise the internal temperature of the engine periodically to remove carbon build up. Carbon build up will kill a diesel engine.

 

I’m feelin’ a little crabby today. Can you tell?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 3:20 AM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM

 

 

Hi Mark,

Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

 

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

 

In other words it says to gun the engine several times while it is in neutral.

 

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

 

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna

 

 


Porter McRoberts
 

Thanks Mark. 
If temp is the final data point, we cruise at about 79-80. What should be the goal?
Thanks again!
Porter


On Jul 7, 2018, at 11:13 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Porter,

 

It really doesn’t matter how you do it but you need to create internal engine heat to clean out the engine. This is done with a load on the engine. If in neutral, it will take longer to create a load and heat. In gear while underway will heat up the engine faster.

 

This is true for all diesel engines.

 

Where you run the RPM depends on the engine. Typically, 80% of max power will heat up the engine nicely without too much strain. This is also good for the turbocharger, if fitted with one.

 

How long? At least every couple of hours while underway, if not a little more frequently.. We run ours up every hour for about five minutes. This works for us.

 

Keep in mind, this is not just the ship’s engine but also true for the genset. Running a genset without load will cause carbon buildup. Keep the genset loaded when charging batteries etc. We find it best to run a couple of AC units or do a load of laundry etc. The battery charger only puts load on the genset at the beginning of the charge cycle.

 

Hope this helps.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 11:35 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Ok. Bullshit aside. 

I do have a few real questions, that I’ve had for a while. 

It’s the same for all diesels. Yes?  

Is “racing” out of gear best?  I would think load would be required to increase fuel consumption and thus heat. Fuel burn>>heat dissipation 2/2 raw water flow. 

Forget the rpm. Where is the throttle?  100% down? 80%?  

And for how long?  

 

Many thanks, as always to this great group. 

 

Porter

A54-152. 

 

 

Excuse the errors.  

Sent from my IPhone 


On Jul 7, 2018, at 9:02 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Bob,

 

Wow! Sorry. I didn’t realize I had to be so freaking specific. Seriously! The essence of the post I made is 100% correct. I didn’t intend to make a verbatim quote of the manual. If  I had, I would have used quotation marks. I stated this is OUTLINED in the manual. I did not say this is a DIRECT QUOTE from the manual. Geeez! And, please note I did say 4JH4 manual, not 4JH3 as you are quoting.

 

But if you want specific details of the JH4 Operation Manual, publication number OAJH4-G00102, page 78. I quote, “Periodically operate the engine near maximum speed while underway. This will generate higher exhaust temperatures, which help clean out hard carbon deposits, maintain engine performance and prolong the life of the engine”

This is below the section you quote about running it in idle and speaks specifically about running the engine while underway.

 

Regardless of whether this is done in neutral or in gear while underway, the purpose of the procedure is to raise the internal temperature of the engine periodically to remove carbon build up. Carbon build up will kill a diesel engine.

 

I’m feelin’ a little crabby today. Can you tell?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 3:20 AM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM

 

 

Hi Mark,

Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

 

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

 

In other words it says to gun the engine several times while it is in neutral.

 

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

 

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna

 

 


Kim Kimball <dhk@...>
 

Nicely put, Mark.  The "... this isn't FaceBook" got many a laugh here.

And I also like to know why my rubbish is rubbish, so to speak.  As Chief I broke a lot of stuff before I learned to ask others, and "rubbish" was a perfectly common reply in many of our chief'y discussions ... as long as there was a "why" to go along with it.

Kim

(Lapsed USCG licensed Chief Engineer, soon to be Amel sailor  ... just the minor detail of selling my house in the mountains ... and clearing out 20 years of acquired rubbish.)


On 7/6/18 4:07 PM, 'Mark Erdos' mcerdos@... [amelyachtowners] wrote:
 

Barry,

 

Rather than just trash another member’s post, perhaps you could support your argument with some cold hard facts. After all, this isn’t FaceBook.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Friday, July 6, 2018 5:41 PM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

I would not do what Pat suggests, that’s rubbish.

 

Kind regards

Barry & Robyn

Tradwinds III SM 171

--

Kind Regards
Barry Ferguson

Email: seagasm@...
Mobile/cell: +61 477 652 046
PO Box 1339
Hervey Bay Qld 4655
Australia



Mark Erdos
 

Porter,

 

It really doesn’t matter how you do it but you need to create internal engine heat to clean out the engine. This is done with a load on the engine. If in neutral, it will take longer to create a load and heat. In gear while underway will heat up the engine faster.

 

This is true for all diesel engines.

 

Where you run the RPM depends on the engine. Typically, 80% of max power will heat up the engine nicely without too much strain. This is also good for the turbocharger, if fitted with one.

 

How long? At least every couple of hours while underway, if not a little more frequently. We run ours up every hour for about five minutes. This works for us.

 

Keep in mind, this is not just the ship’s engine but also true for the genset. Running a genset without load will cause carbon buildup. Keep the genset loaded when charging batteries etc. We find it best to run a couple of AC units or do a load of laundry etc. The battery charger only puts load on the genset at the beginning of the charge cycle.

 

Hope this helps.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 11:35 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

Ok. Bullshit aside. 

I do have a few real questions, that I’ve had for a while. 

It’s the same for all diesels. Yes?  

Is “racing” out of gear best?  I would think load would be required to increase fuel consumption and thus heat. Fuel burn>>heat dissipation 2/2 raw water flow. 

Forget the rpm. Where is the throttle?  100% down? 80%?  

And for how long?  

 

Many thanks, as always to this great group. 

 

Porter

A54-152. 

 

 

Excuse the errors.  

Sent from my IPhone 


On Jul 7, 2018, at 9:02 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Bob,

 

Wow! Sorry. I didn’t realize I had to be so freaking specific. Seriously! The essence of the post I made is 100% correct. I didn’t intend to make a verbatim quote of the manual. If  I had, I would have used quotation marks. I stated this is OUTLINED in the manual. I did not say this is a DIRECT QUOTE from the manual. Geeez! And, please note I did say 4JH4 manual, not 4JH3 as you are quoting.

 

But if you want specific details of the JH4 Operation Manual, publication number OAJH4-G00102, page 78. I quote, “Periodically operate the engine near maximum speed while underway. This will generate higher exhaust temperatures, which help clean out hard carbon deposits, maintain engine performance and prolong the life of the engine”

This is below the section you quote about running it in idle and speaks specifically about running the engine while underway.

 

Regardless of whether this is done in neutral or in gear while underway, the purpose of the procedure is to raise the internal temperature of the engine periodically to remove carbon build up. Carbon build up will kill a diesel engine.

 

I’m feelin’ a little crabby today. Can you tell?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 3:20 AM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM

 

 

Hi Mark,

Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

 

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

 

In other words it says to gun the engine several times while it is in neutral.

 

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

 

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna

 

 


Porter McRoberts
 

Ok. Bullshit aside. 
I do have a few real questions, that I’ve had for a while. 
It’s the same for all diesels. Yes?  
Is “racing” out of gear best?  I would think load would be required to increase fuel consumption and thus heat. Fuel burn>>heat dissipation 2/2 raw water flow. 
Forget the rpm. Where is the throttle?  100% down? 80%?  
And for how long?  

Many thanks, as always to this great group. 

Porter
A54-152. 



Excuse the errors.  
Sent from my IPhone 

On Jul 7, 2018, at 9:02 AM, 'Mark Erdos' mcerdos@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Bob,

 

Wow! Sorry. I didn’t realize I had to be so freaking specific. Seriously! The essence of the post I made is 100% correct. I didn’t intend to make a verbatim quote of the manual. If  I had, I would have used quotation marks. I stated this is OUTLINED in the manual. I did not say this is a DIRECT QUOTE from the manual. Geeez! And, please note I did say 4JH4 manual, not 4JH3 as you are quoting.

 

But if you want specific details of the JH4 Operation Manual, publication number OAJH4-G00102, page 78. I quote, “Periodically operate the engine near maximum speed while underway. This will generate higher exhaust temperatures, which help clean out hard carbon deposits, maintain engine performance and prolong the life of the engine”

This is below the section you quote about running it in idle and speaks specifically about running the engine while underway.

 

Regardless of whether this is done in neutral or in gear while underway, the purpose of the procedure is to raise the internal temperature of the engine periodically to remove carbon build up. Carbon build up will kill a diesel engine.

 

I’m feelin’ a little crabby today. Can you tell?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 3:20 AM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM

 

 

Hi Mark,

Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

 

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

 

In other words it says to gun the engine several times while it is in neutral.

 

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

 

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna

 

 


Mark Erdos
 

Bob,

 

Wow! Sorry. I didn’t realize I had to be so freaking specific. Seriously! The essence of the post I made is 100% correct. I didn’t intend to make a verbatim quote of the manual. If  I had, I would have used quotation marks. I stated this is OUTLINED in the manual. I did not say this is a DIRECT QUOTE from the manual. Geeez! And, please note I did say 4JH4 manual, not 4JH3 as you are quoting.

 

But if you want specific details of the JH4 Operation Manual, publication number OAJH4-G00102, page 78. I quote, “Periodically operate the engine near maximum speed while underway. This will generate higher exhaust temperatures, which help clean out hard carbon deposits, maintain engine performance and prolong the life of the engine”

This is below the section you quote about running it in idle and speaks specifically about running the engine while underway.

 

Regardless of whether this is done in neutral or in gear while underway, the purpose of the procedure is to raise the internal temperature of the engine periodically to remove carbon build up. Carbon build up will kill a diesel engine.

 

I’m feelin’ a little crabby today. Can you tell?

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, July 7, 2018 3:20 AM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] engine cruising RPM

 

 

Hi Mark,

Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

 

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

 

In other words it says to gun the engine several times while it is in neutral.

 

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

 

Bob and Suzanne, KAIMI #429

La Maddalena, Sardegna

 

 


rossirossix4
 

Hi Mark,
Regarding "Running a lower RPMs without load will shorten the life of the engine unless it is pushed up at least once per hour for about 5 minutes. This is outlinede in the Yanmar operation manual."

This is not to challenge the veracity of your statement but I cannot find that in my Yanmar manual. Maybe you have a different manual and it would be helpful (really) to have you quote what it says. 

What my 4JH3-HTE Operation Manual says (on page 30 section 4.6) is: 

"When operating the engine at low speed ffor long periods of time, race the engine once every 2 hours"..."Racing the Engine, Morse Remote Control Handle Pull out the handle lever...and shift the engine speed from high to low several times...Racing the engine removes carbon built up in the compustion chamber around the fuel injection valve.  Neglecting to race tthe engine will cause the exhaust to turn black and lower the efficiency of the engine".

In other words it says to gun the engine several times while it is in neutral.

Like others, we vary my speed between 1600 and 2200 for cruising and can cruise up to 2400 rpm.  We also run it at say 2800 for 5 minutes or so periodically.  However, I cannot find where Yanmar recommends this.  There are postings in this group (not yours) that say to run it full out for 5 minutes, even full out fo 30 minutes but I don't think that is advisable. Seems that vibration is higher and it might be hard on the transmission and c drive as well.  Like most of us we vary the speed and run it harder at times but we also do the "Racing" procedure that is in our manual.

Bob and Suzanne, KAIMI #429
La Maddalena, Sardegna

 


Mark Erdos
 

Barry,

 

Rather than just trash another member’s post, perhaps you could support your argument with some cold hard facts. After all, this isn’t FaceBook.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Curacao

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Friday, July 6, 2018 5:41 PM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 

 

I would not do what Pat suggests, that’s rubbish.

 

Kind regards

Barry & Robyn

Tradwinds III SM 171

--

Kind Regards
Barry Ferguson

Email: seagasm@...
Mobile/cell: +61 477 652 046
PO Box 1339
Hervey Bay Qld 4655
Australia


Patrick McAneny
 

Barry, " Rubbish" , that was a bit harsh, all I suggested was to run it at a rpm that sounded good,in other words not laboring too hard, and then once in awhile run it a little harder to blow out carbon deposits. Sounds like what you do. Go back to bed mate, and get up on the other side.
Pat
SM #123


-----Original Message-----
From: Barry Ferguson seagasm@... [amelyachtowners]
To: amelyachtowners
Sent: Fri, Jul 6, 2018 5:40 pm
Subject: Re: [Amel Yacht Owners] engine cruising RPM

 
I would not do what Pat suggests, that’s rubbish.

Kind regards
Barry & Robyn
Tradwinds III SM 171
--
Kind Regards
Barry Ferguson

Email: seagasm@...
Mobile/cell: +61 477 652 046
PO Box 1339
Hervey Bay Qld 4655
Australia


Barry Ferguson <seagasm@...>
 

I would not do what Pat suggests, that’s rubbish.

Kind regards
Barry & Robyn
Tradwinds III SM 171
--
Kind Regards
Barry Ferguson

Email: seagasm@...
Mobile/cell: +61 477 652 046
PO Box 1339
Hervey Bay Qld 4655
Australia


Patrick McAneny
 

Ryan , I have a Volvo TMD22A ,I also have a fixed prop for now,soon going to purchase a feathering prop, and I max out at 3100 rpm @ 8.3 kts., 2200 sounds good and gets me 6.5 kts. However max rpm on this engine is 4500 and I have been wrestling with how I should pitch my new prop. The prop manufacturers believe I should be able to attain 4500, otherwise I am leaving HP. on the table. But 80% of that would be 3600 RPM and I don't want to run the engine at those rpms all day, fuel/noise and wear. Your in one of those gray areas ,where there is no correct or incorrect answer. Take her up until you hear a sweet spot and run her there ,then once in awhile take her up to a full gallop. 
Pat
SM Shenanigans


-----Original Message-----
From: Ryan Meador ryan.d.meador@... [amelyachtowners]
To: amelyachtowners
Sent: Fri, Jul 6, 2018 2:36 pm
Subject: [Amel Yacht Owners] engine cruising RPM

 
Hi all,

I've dug through the forum history on the topic of the "correct" RPM range for the Super Maramu, and I haven't quite found what I want.  What I have learned is there probably is no single, correct answer -- it depends on the engine and the prop.  But what I really want to know is not what RPM I should be seeing at wide open throttle, but what RPM I should be cruising at?  By this I mean the RPM you would use if you needed to motor for a long period of time.  If the max RPM is different for everyone, it stands to reason that cruising RPM should also be different for everyone.  Is there some way of calculating this RPM from the max?  I've heard a rule of thumb of 80% of max RPM, but given that some of our engines are "over-propped" by design, I don't know if it applies, or even if it's a good rule in the first place.  Should we rev to whatever is necessary to go a certain speed?  Is there any harm in operating the engine close to/at wide open throttle for extended periods of time?

For the record, I have a Volvo TMD22 (B?)..  I typically cruise at around 2400rpm, which yields a boat speed of about 6.5kts.  I have a fixed three-blade prop (probably the original spare).  I think the boat went faster at this RPM last year when I first bought her, but that could be me misremembering the RPM, or the tachometer going out of calibration, or the fact that I badly need a bottom job (though I had it scraped only a couple weeks ago).  I do not know my max RPM; my engine needs a new timing belt and I don't think it's prudent to stress it until that is replaced.  The fastest I've gone is about 2600 and I'm sure it can go higher.  I saw around 7.2kts STW at that speed.

Thanks,
Ryan and Kelly
SM 233 Iteration
Boston, MA, USA