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 

Www.fouribis.com

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

 

 

From: Ian & Judy <ianjudyjenkins@...>
Date: 8 July 2018 at 21:50:01 EEST
To: "amelyachtowners@..." <amelyachtowners@...>
Subject: Re: [Amel Yacht Owners] Re: Onan Water Pump

Hi Mark and Duane , 

Having spent a couple of hours this morning fitting a new impeller to my Onan plus cleaning the broken impeller blades from the heat exchangerwould be interested in that same item - can you send me the reference 

On 8 Jul 2018, at 15:40, sailor63109@... [amelyachtowners] <amelyachtowners@...> wrote:

Mark,

Thanks for the photo and the part reference.  I was wondering how I would support a heavy bronze fitting off the hose, but the plastic one you used appears not to need support, so another problem solved!

Thanks!

Duane

Mark,

Thanks for the photo and the part reference.  I was wondering how I would support a heavy bronze fitting off the hose, but the plastic one you used appears not to need support, so another problem solved!

Thanks!

Duane

 

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 

Www.fouribis.com

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

 

 

 

I stumbled across this video yesterday.  Apparently Nikimat (2001 Super Maramu, Hull # 289) is going to be parted out to rebuild Agapanthe (Rafael's boat a 1999 Super Maramu, Hull #246).  Both were totalled in Hurricane Irma at St. Martin.  I only post this to show the toughness of these boats.  I know many of us wondered exactly what kind of damage it would take to sink a Super Maramu.  Despite severe damage and being nearly chopped in half,  Nikimat looks to be in remarkably good condition considering what she lived through in her final hours.  (I did check with Alexandre before posting this).  Despite everything he's gone through, he continues to be a leader in this great community, helping others.   

 

http://picbear.online/used_boats_for_sale_caribbean

Brent Cameron

Future Super Maramu owner

 

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 

Www.fouribis.com

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,

 

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 

Www.fouribis.com

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!  We’ll get there too fast!  

Thanks again

Porter

A54-152

On Jul 7, 2018, at 1:49 PM, Courtney Gorman Itsfun1@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Porter both Joel and Bill told me to run my engine max 1 hr out of every to to keep it and the turbo happy 

I just wait until I want to hurry then kick ass 

Not fuel efficient but if everything else stays happy then........

Same with cars run them hard sometimes or they have issues 

Cheers 

Courtney 

sv Trippin 54 #101

Grenada 

On Jul 7, 2018, at 11:36 AM, John Clark john.biohead@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Hi Ryan,

  TAMD22 with fixed prop,  at survey with fresh bottom and clean prop we maxed out at 2700rpm and 7-8 knots.  19 no later waiting for haul out and fresh paint we are maxing out around 2400 rpm and 6.5 kts.  Prop had some groth that a diver scraped a few months ago...probably not the cleanest prop at the moment.

John

SV Annie

about to run south from Beryl....

On Fri, Jul 6, 2018, 2:36 PM Ryan Meador ryan.d.meador@... [amelyachtowners] <amelyachtowners@...> wrote:

 

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