Which engine?...............

[Nautical]

Suppose ( hypothetically of course ) one was to commission a new build for a 53' heavy displacement go any where, any time, any weather type of expedition type boaty thing. Fully custom built to your exact spec. Steel hull (based on north sea fishy boat design) weighs in about 45 ton fully loaded with about 9000 litres of fuel. Yard give you option on main engine propulsion of following.

Cummins QSM11 continuous rating 455hp

Cat C12 Continuous rating 460hp

John Deere Continuous rating 400hp (more torquey though)

Volvo D12 (commercial version) rated 450hp

Man D2876LE403 continuous rating 450hp


Which motor does the esteemed panel feel the best engine for the job, price isn't a major issue (but does matter) but absolute total reliability is (if there is such a thing with engines).

Or as they have also suggested, a remanufactured Gardner 8LXB but they are serious money these days and although only push around 230 hp do have absolute whopping torque displacing 24 litres. However chap says switch on and don't worry about switching it off till few weeks later it would run for months non stop.

All this not my bag normally so haven't much experience but I know there are some serious cruising folk out there that know the score.

Thanks

 

[Nautical]

sorry should have said, two options Gardner can only be fitted to an existing hull with new upper works and refitted cus doesn't have all the emmissions gubbins. tothers would be for a new build.

 

[burgundyben]

which one gives best after sales support in the areas you'll be visiting?

 

[Deleted User YDKXO]

You should read Robert Beebe's book Voyaging under Power which has recently been revised by John Leishman of Nordhavn. Coincedentally, I was reading the chapter on engine selection for long distance ocean cruising type boats last night
Basically, you need an engine whose life is measured in tens of thousands of hours rather than just thousands. Leishman reckons you need an engine which is going to operate for upto 20,000 hrs before requiring a rebuild, equivalent to 1-2 circumnavigations. His advice is to look for an engine with 'loads of iron and naturally aspirated'. That means no turbocharging, no aftercooling and a power to cubic capacity ratio not less than 1hp per 4 cu.in. Most marine diesel engines are turbocharged and aftercooled and have power/capacity ratio of 1hp per 1-2 cu.in. This is a reflection of the drive to get ever increasing power out of ever smaller engines; the trouble is that, in Leishman's opinion (IMHO he's right), such engines will have relatively short lives
In fact he states that it is increasingly difficult to find engines that meet his criteria for an ocean cruiser and, in his opinion, two of the very few manufacturers that produce suitable engines are Lugger and John Deere which is why he fits them in his Nordhavns. He also looks for serviceability in engines. For example he won't consider engines that have unlined cylinder bores, as some Cat engines do. His views in the book on keel cooling for the engine and dry exhausts are worth reading too. He considers that saltwater in the cooling system with wet exhausts, as fitted to the vast majority of boats, is detrimental to component life and unsuitable for a long distance boat
Interesting that you've got a power requirement of over 400hp. This seems higher than other displacement boats. For example the Nordhavn 55 which displaces 56t and carries 9000l of fuel makes do with 1 x 330hp John Deere engine. Any idea why you need 400-450hp?

 

[Nautical]

Thanks for that mike, good question why 450 hp, so I asked, hull is acutually 61' OA and displacement is not 45 tons it would be approx 62 tons (ish) loaded, 45 is light so they reckon that is the size engine you need to run constantly for days at 2/3 rd power with enough oomph to run the pto for hydraulics for the stabilizers and steering gear. I am not so sure cus the commercial version for trawling only has 500 hp and they must be hauling hellish weight. Maybe its that peculiar curve that a bigger engine running slower burns less in a diplacement hull than a smaller one running harder.

Personally I like the idea of the Gardner in a refinished hull and new everything else, if I remember correctly Scott cowper's boat had a remanufactured 8LXB and he went the hard way round, boat was left trapped for months in ice and just restarted and off he went.

 

[whisper]

I've had Gardners in my trucks in a former life - wonderful tools, albeit totally outclassed in the power:weight ratio stakes.

How about fitting twins /forums/images/graemlins/cool.gif /forums/images/graemlins/cool.gif

 

[Deleted User YDKXO]

Leishman makes the point in the book that having too big an engine is almost as bad as having too small an engine in that an engine that is not sufficiently loaded may not be operating in its most efficient state and may suffer wear such as bore glazing as a result
A Gardner seems like a good choice but I guess they are massive for their power output. Any constraints on engine space?

 

[Nautical]

Good point, think it needs a bit more research and input from an engineer as obviously a crusing boat this size is not hauling tons of nets and running hydraulic winches etc. No real restrictions on the engine room its a stand up walk around affair. Gardner is big old lump though, its twice the capacity of the Cat C12 and twice the weight but no turbos or aftercoolers and not an electronic thingy in sight.

here...... Gardner 8

 

[Deleted User YDKXO]

Yup, that's the same Gardner that Noah specified for his cruiser

 

[PCUK]

Cummins are cheapest for spares and don't pretend their marine stuff is different from truck. That's why you can pick up all your marine spares from the local truck dealer. Wins hands down. US coastguard can't all be wrong.

 

[jets4me]

Hi what oil sould be use in a gardner 8lxb engine with 9000 hrs on clock thanks

 

[dieselboy]

just a thought... last two boats to hold the round the world record had Cummins fitted...

 

[davids0865]

OOH, different and interesting thread!

If I where speccing an explorer style yacht (in my dreams), my preference would be for an donk of the Gardner type, as instinctively a low output per litre engine should last longer and be more reliable.

I would also spec a wing/get you home engine that primarily ran hydraulics and or genny with PTO for emegency use.

Very interesting comments re keel cooling and dry exhausts, I would seriously consider that.

And a seachest rather than through hulls.

 

[gordmac]

What do they put in the fishing boats? I would think fishermen will have a good handle on reliability and running costs as it is their living.

 

[JerseyDiver]

Sounds like a great project if it comes to fruition.

Have a look at setsail.com. They have an interesting article about engine selection as well as loads of interesting articles about long distance cruising etc.

I can't remember in detail but the point above about having too big an engine as a disadvantage is also discussed.

 

[davids0865]

Go on then you big tease, are ORY planning a new product range?

 

[Vidas]

I'm possibly biased but Gardners would be the way forward, I've 2x6LW's on my 30 ton 49'steel boat
Go for twin 6's as opposed to one 8 easier manovering, and safety in the event of a failure!
I've a friend who ran his 12hrs a day 6 days a week for 12 years , only changed oil & Filters , no other servicing!!
Michael Harrison @ Gardner marine is extremely helpful and can supply re manufactured engines

 

[Whitelighter]

This thread is nearly 10 years old.

 

[davids0865]

Ooops, so it is:disgust:

 

[PowerYachtBlog]

Cummins are cheapest for spares and don't pretend their marine stuff is different from truck. That's why you can pick up all your marine spares from the local truck dealer. Wins hands down. US coastguard can't all be wrong.

This, and the Deere second. No experience on Deere but they seem to be put in a lot of displacement type craft in recent years.