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18-05-2019, 22:18
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#151
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Registered User
Join Date: May 2014
Boat: Beneteau Idylle 15.50
Posts: 349
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by olaf hart
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For most of them I am not sure but from what I have heard and seen it was likely cylinder glazing from being run to light or not bringing it properly up to temp. That is not going to hurt in the short term but over the long term
I know a fellow has the 50hp turbo version of the 2003 engine. A customer of his was replacing the non-turbo version because it would not start well and kept blowing its main oil seals and the guy with the 50 hp took it for parts.
The head was off the non-turbo version and we could see that the cylinders were so shiny you could read a playing card in the reflection. He had to do a head gasket on the 50 and he said the difference was night an day. The 50 is run hard and he said the cylinders had no shine on them at all.
We talked about it and though that the problem with the seals was caused by the blow by on the pistons on the glazed cylinders and a lack of a crankcase ventilator on that particular model/version. We both agreed this was from running to light to long.
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18-05-2019, 22:22
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#152
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Registered User
Join Date: Feb 2019
Location: North west BC.
Posts: 128
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by Paul L
Stu,
This is the Interweb. It is not your experience or qualifications that count. Just make bold, absolute and unsupported statements like no other opinion could be considered less it be considered obviously ridiculous. Then you are gold.
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For the record, I wanted to post something sarcastically funny here...
But.. he is right.
RR
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18-05-2019, 22:24
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#153
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Registered User
Join Date: Jun 2010
Posts: 726
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Re: Why do people replace diesel engines in a sailboat?
Thanks Dark Horse, that makes sense, didn’t realise the engine had no crankcase ventilator, will have a look next time I am aboard...
Another question, IIRC on some Of their models, Yanmar recommends reviving them right up for a short while before shutting them off.
Given the notorious exhaust elbow issues with the 2003, I have often wondered it that might also be a good idea for them.
When I change mine out, there is usually thick carbon inside the cooling water passages, don’t know how it gets there, but wonder if revving it up the cooling water would clean out the passages.
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18-05-2019, 22:48
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#154
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Registered User
Join Date: May 2014
Boat: Beneteau Idylle 15.50
Posts: 349
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by olaf hart
Thanks Dark Horse, that makes sense, didn’t realise the engine had no crankcase ventilator, will have a look next time I am aboard...
Another question, IIRC on some Of their models, Yanmar recommends reviving them right up for a short while before shutting them off.
Given the notorious exhaust elbow issues with the 2003, I have often wondered it that might also be a good idea for them.
When I change mine out, there is usually thick carbon inside the cooling water passages, don’t know how it gets there, but wonder if revving it up the cooling water would clean out the passages.
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I am not sure why they recommend reving them. Diesels regardless of whether you pull a stop cable, press a stop button or just turn the key off all stop the same way. The high pressure fuel pump is shut off buy the movement of the fuel shut off lever. No fuel no run. If you rev them up I guess your assured of getting all the fuel out of the cylinders.
But millions and millions of tractors, bulldozers, back hoes, excavators etc are shut off with a simple key without reving and the engines don't seem to die... Other stuff breaks but the engines keep on going so clearly the reving up is not really necessary. Of course this is just my opinion from my observations and nothing more.
Lots of yanmars with plugged exhausts as well. When mine plugged I just built an elbow set up out of 2" pipe and welded in a tee at the appropriate point in the appropriate direction. Seemed to work just fine and it was not 500$. Yanmar parts are 2x US price in Canada. Thats after exchange...
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18-05-2019, 23:38
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#155
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Registered User
Join Date: Jun 2010
Posts: 726
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by Dark Horse
For most of them I am not sure but from what I have heard and seen it was likely cylinder glazing from being run to light or not bringing it properly up to temp. That is not going to hurt in the short term but over the long term
I know a fellow has the 50hp turbo version of the 2003 engine. A customer of his was replacing the non-turbo version because it would not start well and kept blowing its main oil seals and the guy with the 50 hp took it for parts.
The head was off the non-turbo version and we could see that the cylinders were so shiny you could read a playing card in the reflection. He had to do a head gasket on the 50 and he said the difference was night an day. The 50 is run hard and he said the cylinders had no shine on them at all.
We talked about it and though that the problem with the seals was caused by the blow by on the pistons on the glazed cylinders and a lack of a crankcase ventilator on that particular model/version. We both agreed this was from running to light to long.
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Interesting, I just checked up the internets.
The VP 2001, 2002 and 2003 series all have PCV, it’s just the whole system including the inlet port is incorporated into the valve cover, so you can’t see them.
Anyhoo, thanks for the warning to look out for glazing, I will push the engine even harder from now on.
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19-05-2019, 00:20
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#156
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Registered User
Join Date: Jul 2005
Location: Bellingham
Boat: Outbound 44
Posts: 9,319
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by Chotu
Another thread got me to thinking. Why is it that people decide to re-power?
Assuming you have a working engine, a diesel engine, what is the point?
I see a lot of people pull out older engines and put in a brand new one. I’m thinking of ones like an old Perkins. Sure, they look old. And they probably don’t get as great fuel efficiency as the new ones. But why replace them if they are still running?
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I repowered with a small Yanmar because my Volvo Penta 2003 turned into death by a thousand paper cuts. Just a string of small to medium bills that soon added up to half an engine. Should have done it sooner.
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19-05-2019, 04:36
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#157
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Registered User
Join Date: Feb 2017
Location: Panama, Central America
Boat: CT 49, 1989
Posts: 969
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by john61ct
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Or even safer, dont have a boat and stay at home. No engine or oars to break.
You advocate no electrics engines, or no engine. I also see you are an LFP state of the art enthusiast. But dont like spending on upgraded alternators.
Your boat does sound interesting!
Any build thread and links please?
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19-05-2019, 05:05
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#158
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Registered User
Join Date: Jun 2008
Boat: Tartan 40
Posts: 2,460
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Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by Paul L
I repowered with a small Yanmar because my Volvo Penta 2003 turned into death by a thousand paper cuts. Just a string of small to medium bills that soon added up to half an engine. Should have done it sooner.
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That’s why.
key is to do it sooner than later. I was 2K into old engine when I decided so could have been worse
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19-05-2019, 07:12
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#159
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Registered User
Join Date: May 2014
Boat: Beneteau Idylle 15.50
Posts: 349
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by olaf hart
Interesting, I just checked up the internets.
The VP 2001, 2002 and 2003 series all have PCV, it’s just the whole system including the inlet port is incorporated into the valve cover, so you can’t see them.
Anyhoo, thanks for the warning to look out for glazing, I will push the engine even harder from now on.
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I never actually saw the 2003 without the head on it. The owner of the 50 told me it did not have PVC. Maybe the blow by was so great the PVC system could not handle it. I did see the glazed cylinders though and they were shiny shiny.
I am very concerned about fuel usage on our boat as we move to long distance cruising. Its not so much the usage as the range. At 8 knots or 2000 rpm we use 8 liters per hour. At 1600 rpm we use maybe half that. I am also very concerned about engine life. Some where there is a balance. As at least one person has said. You don't have to run them wide open to keep them alive.
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19-05-2019, 07:42
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#160
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Registered User
Join Date: Nov 2013
Location: Philadelphia
Boat: Hinckley 59
Posts: 144
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Re: Why do people replace diesel engines in a sailboat?
Three vital factors haven't been mentioned yet - all related.
1. Was the engine built into the hull - requiring significant deck/cockpit surgery to remove it?
2. Can the mechanic, practically speaking, get access to the bottom end ?
3. For a the proposed new one, how much engine bed modification would be needed ?
I've both replaced and removed/rebuilt smaller Volvos. In neither case could we have opened the sump (with the engine still mounted) to make measurements of the crankshaft, much less remove the crank.
Then, I just heard about a 1995 Pearson 36 owner who spent $20 k on a rebuild. The warranty on a new one would have driven me to replace it (subject to #1 and #3 above).
CA
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19-05-2019, 15:32
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#161
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Registered User
Join Date: Feb 2013
Location: Oregon
Boat: Seafarer36c
Posts: 5,563
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Re: Why do people replace diesel engines in a sailboat?
Nascar Cup engines have a really high idle because of the fat tappet cams. Xfinity engines have roller lifters and a lower idle. When they talk about using high tech coatings, I bet cams and lifters are one place they need them.
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19-05-2019, 15:50
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#162
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Registered User
Join Date: Jun 2010
Posts: 726
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by Dark Horse
I never actually saw the 2003 without the head on it. The owner of the 50 told me it did not have PVC. Maybe the blow by was so great the PVC system could not handle it. I did see the glazed cylinders though and they were shiny shiny.
I am very concerned about fuel usage on our boat as we move to long distance cruising. Its not so much the usage as the range. At 8 knots or 2000 rpm we use 8 liters per hour. At 1600 rpm we use maybe half that. I am also very concerned about engine life. Some where there is a balance. As at least one person has said. You don't have to run them wide open to keep them alive.
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I would imagine running hard for an hour at the end of a days motoring would be just as effective as flat out all day, but I have no evidence to back that up.
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19-05-2019, 16:26
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#163
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Registered User
Join Date: May 2014
Boat: Beneteau Idylle 15.50
Posts: 349
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by olaf hart
I would imagine running hard for an hour at the end of a days motoring would be just as effective as flat out all day, but I have no evidence to back that up.
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That is actually recommended if your running slow. Run hard for 20-30 minutes every 2 hrs of slow.
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19-05-2019, 16:59
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#164
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Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by olaf hart
Interesting, I just checked up the internets.
The VP 2001, 2002 and 2003 series all have PCV, it’s just the whole system including the inlet port is incorporated into the valve cover, so you can’t see them.
Anyhoo, thanks for the warning to look out for glazing, I will push the engine even harder from now on.
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All internal combustion engines I am aware of have some form of crankcase vent.
However PCV stands for positive crankcase ventilation, a Diesel has no vacuum so unless a pump has been fitted for this purpose it can’t be a positive crankcase vent, that is on gas engines that have vacuum, the vacuum in the intake manifold is what makes it a positive crankcase vent.
Trivia really the result is the same, but hopefully the manual doesn’t refer to it as a PCV system does it?
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19-05-2019, 17:01
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#165
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Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
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Re: Why do people replace diesel engines in a sailboat?
Quote:
Originally Posted by Ecos
Nascar Cup engines have a really high idle because of the fat tappet cams. Xfinity engines have roller lifters and a lower idle. When they talk about using high tech coatings, I bet cams and lifters are one place they need them.
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Actually nearly all race engines, especially naturally aspirated ones idle at high RPM, this is due to the radical camshaft timing, they won’t idle at low RPM, they will shut down.
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