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03-08-2018, 20:15
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#1
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Registered User
Join Date: Dec 2012
Posts: 4
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Engine replacement Nord Havn 46
We have a John Deere 6068 (TO6068D) by Lugger in a Nord Havn 46. We have to replace the engine. Does anyone know of a comparable engine to the John Deere? Any experience with replacing with another engine? Any advice would be helpful! Thanks
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03-08-2018, 20:22
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#2
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Moderator Emeritus

Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,348
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Engine replacement Nord Havn 46
Why not overhaul the JD?
From my understanding it’s hard to get better than a JD.
I have no idea if it would fit, but I believe the Rolls Royce if you will is a Gardner.
You know that JD is a wet sleeve engine and can easily be returned to new status if you will, you don’t bore them out, you replace the cylinders with new ones.
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03-08-2018, 20:51
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#3
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Registered User
Join Date: Dec 2012
Posts: 4
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Re: Engine replacement Nord Havn 46
We had a piston melt down after 10 hours from last overhaul. Undiagnosed faulty fuel injectors (also rebuilt) or timing. Not sure the cause. We are in Philippines and not easy shipping parts again for another overhaul. The block appears ok, but head is cracked. Shipping replacement parts will cost as much as some new engines, so trying to look at a comparable solution with availability in Philippines.
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03-08-2018, 20:59
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#4
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Marine Service Provider
Join Date: Mar 2008
Posts: 7,709
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Re: Engine replacement Nord Havn 46
Laura....
Consider a de-rated Cummins 6BT-5.9M
180 HP continuous. Bulletproof. I have a pair in a 35 ton power cat with now 12,000+ hours, never had their heads off. They just run and run...
@A64...
A Gardiner would never fit. I tried, but it is a beast....
Good Luck
Dave
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03-08-2018, 21:21
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#5
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Registered User
Join Date: Dec 2012
Posts: 4
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Re: Engine replacement Nord Havn 46
At the risk of appearing obtuse on this, could you please explain de-rated? Thanks very much.
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03-08-2018, 21:31
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#6
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Registered User

Join Date: May 2008
Location: We're technically refugees from our home in Yemen now living in Lebenon
Boat: 1978 CT48
Posts: 5,970
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Re: Engine replacement Nord Havn 46
I replaced my ford mermaid with a JCB 85hp.. no idea about how much trouble it would be as far as required changes.. but I do believe JCB is used in the PI
__________________
James
S/V Arctic Lady
I love my boat, I can't afford not to!
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03-08-2018, 21:41
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#7
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Marine Service Provider
Join Date: Mar 2008
Posts: 7,709
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Re: Engine replacement Nord Havn 46
Laura...
De-rating, simply, is an adjustment to the fuel system to limit the maximum fuel flow rate to the engine, and thus the maximum horsepower produced.
Of course, one can do this manually, by not using full throttle. And most displacement trawler operators do this naturally. But many commercial operators prefer that the engine be physically de-rated to a maximum continuous rating, so that full available throttle for days-on-end will be safe and reliable.
The Cummins 6BT block can be found in 300+HP variants with aftercooling, etc. At those power ratings there is a specified duty cycle, i.e. no more that 30 minutes per 6 hours of operation at the extreme power, for example.
https://cumminsengines.com/ratings-and-definitions
Dave
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03-08-2018, 22:49
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#8
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CF Adviser
Join Date: Oct 2007
Boat: Van Helleman Schooner 65ft StarGazer
Posts: 10,280
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Re: Engine replacement Nord Havn 46
Hi Laura, are you in Subic or further south?
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04-08-2018, 00:55
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#9
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Registered User
Join Date: Dec 2012
Posts: 4
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Re: Engine replacement Nord Havn 46
Danao, Zekes boatyard.
It's on Cebu.
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04-08-2018, 04:32
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#10
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CF Adviser
Join Date: Oct 2007
Boat: Van Helleman Schooner 65ft StarGazer
Posts: 10,280
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Re: Engine replacement Nord Havn 46
Mark Pragnaul from HYS in Subic, had brought into Subic a few engines from Singapore, so is worth contacting
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04-08-2018, 06:47
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#11
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Registered User
Join Date: Oct 2009
Location: Annapolis
Boat: Nordhavn 47
Posts: 797
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Re: Engine replacement Nord Havn 46
I believe you can also run the Nordhavn 46 with the smaller JD 4045 if you wanted to stay with JD and just can’t find the larger engine.
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04-08-2018, 06:55
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#12
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Moderator Emeritus

Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,348
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Re: Engine replacement Nord Havn 46
De rating an engine pretty much assures a very long life, cause when it's being run wide open, it's not really wide open.
it's very common in aircraft, and may be where the term came from.
Cummins is a very good engine as well. and very prolific and as it's an automotive engine and literally millions have been made, parts will be available for a long time.
Then of course there is Yanmar, but I'd rather have a Deere first, then a Cummins, and lastly a Yanmar.
I have an aversion to Green engines and to not offend I'll leave it at that
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04-08-2018, 19:52
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#14
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cruiser
Join Date: Jan 2012
Location: Pangaea
Posts: 10,856
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Re: Engine replacement Nord Havn 46
Quote:
Originally Posted by bdbcat
Laura...
De-rating, simply, is an adjustment to the fuel system to limit the maximum fuel flow rate to the engine, and thus the maximum horsepower produced.
Of course, one can do this manually, by not using full throttle. And most displacement trawler operators do this naturally. But many commercial operators prefer that the engine be physically de-rated to a maximum continuous rating, so that full available throttle for days-on-end will be safe and reliable.
The Cummins 6BT block can be found in 300+HP variants with aftercooling, etc. At those power ratings there is a specified duty cycle, i.e. no more that 30 minutes per 6 hours of operation at the extreme power, for example.
https://cumminsengines.com/ratings-and-definitions
Dave
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I’m also very curious about how his practice works. Our Perkins-Sabre M225ti was de-rated to 185hp from a normal 225hp rating, which is still plenty. We can cruise along all day at only 1200rpm which gets us 7 knots, then 1400-1500 gets us up to hull speed. Is it done mostly for reliability? I’m just used to the high revving Yanmar on our 53 with it’s 3500 red line.
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04-08-2018, 20:28
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#15
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Registered User
Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 3,823
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Re: Engine replacement Nord Havn 46
Quote:
Originally Posted by Kenomac
I’m also very curious about how his practice works. Our Perkins-Sabre M225ti was de-rated to 185hp from a normal 225hp rating, which is still plenty. We can cruise along all day at only 1200rpm which gets us 7 knots, then 1400-1500 gets us up to hull speed. Is it done mostly for reliability? I’m just used to the high revving Yanmar on our 53 with it’s 3500 red line.
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IMO, derating is done to allow the same engine to fill a broader set of requirements. If a new engine design was required for every application, cost would be significantly higher. e.g., the Yanmar 3TNE in my genset is available with various fuel options creating 12hp - 30hp, depending on application, or the Suzuki 20hp outboard on my dinghy...same engine for 9.9hp and 15hp, just alter the fuel system.
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