The Offshore Voyaging Reference Site

New Engine, The Proof is in The Voyage

JHH5_102200As most of our regular readers know, we completed a 10,000 mile, eight month voyage to the Arctic and back on Morgan’s Cloud, our 56-foot McCurdy and Rhodes aluminum cutter in 2011. A voyage that constituted a gruelling test of all the gear on the boat. Here is our report on how the engine and drive-train did:

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Dick Stevenson

John, What do you see as the advantages/disadvantages of a high torque/low revving engine? It sounds as if one of your reasons was for fuel savings which you are pleased to have accomplished. To what degree do you attribute the fuel savings to the low rev/hi torque engine vs the new engine just being 25% smaller? I am also interested by what you mean when you describe the Perkins as an “industrial” engine? Thanks, Dick Stevenson, s/v Alchemy

Dick Stevenson

Dear John, I would like to comment on your statement that parts are readily available by couriers like FedEx. Some parts of the world that may work well, but in many of the countries I have spent time, Customs waylays the delivery and puts complications/expenses in the mix that effectively undermines delivery. Many countries, even 1st world, the best advice, (as absurd as it sounds) for important items, is often to fly out yourself, get the part and return with it in luggage. “Yacht in Transit” usually makes no difference to officials as well. So couriers can and do get the part to the country with speed only to have actual delivery become infuriatingly elusive behind a web of rules, fees, forms and protocols, always in a different language, and usually in a different location from where you are. Dick Stevenson, s/v Alchemy

conny Harlin

Nice to hear that you guys are happy with your “Perkins” with low rpm /high torque layout. You see what a change in fuel-consumption that makes….I would also like to add that a low rpm engine last longer before it’s time for overhaul due to wear of bearing,bushings,seals.
And the best is “No worries about Turbo”failures!!!
ZF is a German quality brand and have been around in the industry like Perkins.
I do like your engine room,,clean, organized,and a NO bilge “Crap” floating around.
I’m glad that you guys are happy with your investment of power ,,,,Conny, S/Y Crusader


Hi John,
Your mention that your Perkins has a 24v energize-to-run solenoid switch certainly caught my attention! Let me describe the events of a delivery from hell, or more specifically from San Diego to Costa Rica. The boat was a 54′ sport fisherman powered two brand new MAN V-10’s. Upon arriving at the fuel dock in Cabo for our first 1200 gallon refill, we were unable to get the engines to restart. One engine would start, but as soon as you tried to restart the second the starter draw killed the first. The “yacht’s” tool kit consisted of a couple of rusty Craftsmen socket wrenches, and as it turned out the owner had run out on an outstanding bill in Cabo so no mechanic would touch it. Next morning everything was back to normal, so after scratching our heads we toddled on south. When we shut the engines down at our next stop we were again dead in the water. The background cause probably stemmed from needing to run the engines at too low a RPM for the regulator settings as we were trying to save fuel and make long runs. (the difference between 8 GPH and 80 GPH on a boat of this type is a mere twitch of the wrist!)

Here is the sequence of the problem: The engines will not run unless they are receiving the full 24 volts required to hold the fuel supply solenoids open. The boat had a generator that runs continuously producing 120v. This in turn was set up to charge the house 12 v battery bank through a charger unit and charge the 24v engine bank through a separate charger. Engine mounted alternators also charged the engine battery bank. There was no crossover switch between the house and the engine batteries, as this would have involved a voltage conversion.

In this set up either a deteriorated battery bank or regulator or 24 v charger failure creates a power boat with zero horsepower rather than 2400 hp! We finally ended up disconnecting the house bank, re-jumping it to produce 24 volts, jump starting the engines from it, and getting enough output from the alternators to bring the engine bank up to 24v.

The take away lesson:
If you have an energize to run propulsion engine system, you MUST have a back up energy source capable of independently producing the juice necessary to keep your engine running. If you depend upon an inverter I’d want two installed in parallel ready to switch on immediately, powered from two separate battery banks. If you are sailing to remote and challenging locations either install a generator as the independent energy source or choose an older engine design that can run independently of electricity.


Hi John,
Sounds like you have adequately thought thru the redundancy problem. Why am I not surprised!

One thing I did find surprising on the MAN installation was how little voltage drop from full charge was required to shut the solenoid.

ps; If you think the sport fisherman was overly complicated you’d love the 112′ Sparkman & Stephens twin engined, active stabilized, triple gen set sailboat I once managed the build for! In fact all boats that try to become floating houses are too complicated, with the possible exception of Steve Davis ‘s designs.

Dick Stevenson

Dear John,
Thanks for the clarifications which, for me, inexorably leads to more questions. Beta and Nanni engines are based on Kubota blocks, some Westerbeke on Mitsubishi blocks. Would you consider them “industrial” engines? The only “built for marine use from scratch” engine that I am aware of is Yanmar (unsure about Volvo, Vetus etc.).
I could see a high revving engine only getting 2-3000 hrs on a boat where there is only 50-150 hrs a year on the clock. Many (or most) sailboats likely fall into this category and they would likely figure they got their money’s worth at 20 to 30 years of use. Those of us who live aboard and go significant distances often clock up 500 and more in hrs. per year. Many (again likely most) have higher revving engines and I do not know any of my cruising friends who believe they will get so few hours out of their engines.
As for fuel economy, I would be very curious as to the actual figures comparing a well set up high revving engine and well set up low revving engine. I suspect it is not all that great for the average displacement sailboat. A conundrum is the fact that basically, lower speeds save fuel dramatically (as measured miles per gal.), but the engine “likes” higher speeds. (My Westerbeke 42B uses approx 0.55 gph to push me 5.0 knots and 0.95 gph gets me 6.0 knots—4500 hrs on eng). I almost never go optimal speed/rpm for the engine (70-80 % of power available if memory serves which would push me approx 6.6 knots) as the fuel usage just shoots up off the charts (mpg drops comenserately). I am not sure how to get around this we all want “reserve” power for emergencies and those times when it is important to pound our way up-current, up-wind and up-swell/wave.
Thanks as always for your thoughts, Dick


Hi John,
I’ve often seen identical block marine engines (including Yanmars) with two different power ratings and service recommendations available from the factory. Often the only difference is the governor settings for RPM, and perhaps the injector pump delivery mapping. So I’m not sure how much difference there really is between a “low speed” and a “high speed” engine in these smaller sizes.

That “yacht rated” 3600 rpm 75 hp engine you mention will in fact produce about 40hp at 2400 rpm. If it were coupled to a controllable pitch propeller like we sometimes use in large sailing vessels it might well run quite comfortably loaded up to work at 2400 rpm and last as long as the same engine rated at 40hp, assuming it has electronic sensor controlled fuel mapping. In order to use the available 75 hp. you need a way to change the propeller loading on the fly.

Choosing a broad torque curve and a simple, non-turbo design like the Perkins gives a long engine life and the widest usable power band that can be absorbed by a fixed pitch prop, even though it might theoretically be outperformed by the set-up I just described.

Keith Jones


I seem to recall that you changed your prop pitch with the new engine installation. Couldn’t some of the fuel economy and performance be attributed to that change?

S/V Pearl


I’ve done a couple of AquaDrive installations but have no long term experience with them. What is your bottom line conclusion? Is the cost justified?

Svein Lamark, Norway

Hi John, have had a Perkins like yours in a sail boat. The engine crashed after 12 000 hours by accident. I think they last about 22 000 h i fishingboats before main service. Clean dieseloil without water is important to make them run long and fuel polishing is good.
I put in a Yanmar with a ZF and Aqua drive. The Yanmar is still ok and I hope it will last til 22 ooo hours. The ZF broke down in The Arctric with no wind. A friendly fisherman told me that I used the wrong oil and gave me 5 gallons of SAE 30 single grade oil. ZF told me not to use it but I tried and has now made 8 000 hours on the wrong oil.
Aqua drive needs good alignment! The two shafts can be on different levels, but they must be paralell. It is a common mistake to beleave that they can absorbe everything. I make the alignment at normal speed with warm engine, ca 2000 rpm, off shore. Alingnment can not be done in harbour or ashore. To do this you need laser tools. Fixtur laser has the best tools, but there are many options. My aquadrive has lifetime of 100 000 hours. I was first offered the 3000 h, but denied, got 30 000 h offer, but choose 100 000h. It has now made 20 000 hour without service. It is bigger than yours, but the price is almost the same.
Your shaft seems to small, the bedding to light and the gearbox must be fixed. The bedding should be stiff also sideways, bed weight the same as the engine, but better two times the engine. Then it is quiet. If you have rubber moutings, get them as stiff as possible, but better is to leave the engine direct on the bedding.
In my motorboat the engine runs at 300 rpm and use 150 grams diesel oil pr. hour pr. HP. That is 40% less than your Perkins. It has has no gearbox, the ZF takes about 20% of your energi production. It has now passed 120 000 hours and is expected to do 200 000h before next service. I always heat the engine before start and start the lubrication oil pump before start. So when I start the engine is warm with 3 bar oil pressure. That makes the engine last.

Svein Lamark, Norway

Hi John, i do not expect to do the 100 000 h, I want the safety of it. The cost is almost the same. If you go to Svalbard, there is no boatyard.
The modern theories of rotating shafts are not well known. But all Nato-ships are very quiet, mostly the subs. When Kongsberg Weapon and Thoshiba published how to make a quiet propeller, all the Nato gouvernmets were angry. Norway had to send the spyship Marjata to the Murmansk fiord to observe the new russian quiet subs. This is why theories of rotation shafts are not known to you and your boatyard. But they are simple and not costly to follow and you can improve your boat a lot. It is the theory of the stright line. Easy physics for an old sailor used to the same maths with his sextant. If you know sinus and tangens, you can do the theoretical part of it.
Sweden is outside Nato and the swedish company Fixturlaser has published how to get a quiet engine and shaft. Some of those principels I have mentioned above. I understand that you do not want to take out your Perkins and do your istallation proper. We call that a comprimis. What risks do you take sailing your way: water leaks in the through hull fittings, oil leak in the gearbox, oil leaks between gearbox and engine, and bearings in the aqua drive break down. But with a good sailboat that is not important to many.
I have with a friend adjusted many sailboat engines like yours without doing any rebuilding. We use laser tools offshore. We try to find the best possible solution of the problem within the ecsisting frames. Often we just do small adjustments like lifting the front end of the engine something like 2mm. The normal result is: 30% noice and vibration reduction, 10 -20% reduction in oil consumption. Lifetime of the bearings increased almost to the normal 30 years. If you say you dont like the cost of this, I will do it for free to you in Norway.
Aquadrive is an offspinn from the car industry. Car parts are much cheaper than marine parts. I buy aquadrive parts by Kardang aksel in Oslo to a fair price. You do not have to pay much for that stuff.

Svein Lamark, Norway

Hi John, Morgan’s Cloud and crew are very much welcome back to Norway. You just have to cross the fiord. We will fix some laser sensors to your shaft, gearbox and Perkins and then sail off until the engineroom has the normal temperature. Then we do the alignment. We work mostly on The West Coast. The oil industry (drilling platforms, work boats) has lots of rotating shafts with lots of power and speed. They need perfect alignment. Here it is not a question of noise, but to prevent brake downs. Stops are costly.
Last week I was sailing in the Skagerak and reading 3 different pilot books of Norway. I have now ordered yours and will bring it with me on a two week trip in The Barensts Sea, starting next week. I look forward to that.
Best regards and fair winds to you.

Emery Laroche

Hello John,

Wow, I’ve been reading through your online book on ”Engines for cruising boats”, etc., and the wealth of information is, well, ….overpowering ( yeah, I couldn’t help that one…). But truly, it’s tremendous.
So, to make a long story short, we’re looking at possibly /probably replacing our 23 year old / 2600hr Perkins M80T on our 45′, 18 to 20 tons at full load, steel centerboard prior to departing with the kids on our longterm, part high latitude, life.
I’ve been able to get ”some” idea of where to start but would like the counsel of a pro on selecting the proper engine, transmision, prop, etc, and I want to pay for it! – do you have someone you could recommend?
Best regards


Hello John,
Thanks for the response – will get in touch with Matt for sure.
Best regards


Hello John,

While I wait for Matt to have a moment to respond to my email – To get me started, would you have some form of calculation guideline for sizing the appropriate engine that takes into account displacement as well as hull speed, plus the fact that with your latest re-power you still ended up with ”some” glazing – we are not at the moment planning to go to Antarctica, but Patagonia, Greenland and Alaska among others (dreaming big).
Many thanks again for all the info and best regards.

Marc Dacey

Emery, if it’s any help, I put in a new Beta Marine 60 in our 16 tonne 42 foot steel pilothouse cutter a couple of years ago, and we are very happy with it to date. I have a 19 x 15 four-bladed Variprop and I can maneuver with authority even with a semi-full keel. They seem to me to be great, strong engines and are easy to service. We installed it with a ZF25 M hydraulic transmission and had custom engine stringers, soft mounts and a thrust bearing for an Aquadrive unit, which I recommend for any metal boat that is re-engining, as (aside from addressing alignment issues) this set-up really reduces vibration and noise.

If you think the 60 isn’t enough, Beta sells a 75 hp today and are introducing a new 70 hp in September that might suit your needs perfectly.


Thanks John,
I was having a hard time coming up with HP size, as it would seem to me that displacement as well as hull speed were both important factors to consider as they can vary quite a bit + I’ve been seeing the rule of thumb of 2 to 5 hp per ton depending where you look – not much help that one…
FYI – Beta 60 = 4 cylinder – 2424cc – 56hp max at 2700rpm
Best regards


Thanks John,
I’ll hang on a little to see if Matt has a little free time for me – Was planning on re-powering in the fall but will probably get a better price if I order sooner rather that latter (new prices coming later this summer)
What are your thoughts on the Autoprop coupled to one of these (60 vs 75) – is it worth the investment vs the performance (light air, etc.) for our boat/hull type?
Thanks again, and again, and again….


Thank you John,
In the meantime, got in touch with Matt and looking forward to working with him.
Also got in touch with Beta in Vancouver about what they would recommend engine wise and to get the fuel consumption map

– on this last issue, Beta Canada’s answer;
”I have failed to obtain a fuel map, apparently Kubota guard this information closely. The consumption curve that Beta supply is all we can get from Kubota”

Any suggestions ?
Best regards

Frans Botman

Hello John,

Read your article with great interest.
Checking the Perkins site it seems they only have the low rev, high torque engine you installed.
Nothing smaller for 40~45 foot boats.
Any other engine manufacturer you are aware of that builds similar?



Rob Gill

Hi Frans,
Volvo D2 40 which might suit, is based on the Perkins Engine, or the D2 55 – ours has a “Proudly Made by Perkins” plate on the back of the block. Volvo has added more electronic timing and fuel injection controls which our fairly basic 2002 engine didn’t have. You would want to check this out carefully, because the electronics can be problematic on some Volvos I have heard.
Very satisfied with our Volvo/Perkins engine on our 47 foot yacht – reliable, frugal and almost no signs of wear in latest oil change analysis, after nearly 2000 hours.
Br. Rob

Frans Botman

Thanks John and Rob,

Will look into that. Should even be easier in Europe where I live given the provenance of the manufacturer


Kevin MacDonald

I repowered my sailboat with a Kubota D1105. It has a 12 volt energise -to-run solenoid that can be removed and the hole covered with a blocking plate. When the solenoid is energised the plunger retracts and is therefore the same as removing the solenoid. Now, no electric is needed for the engine to run. Of course the manual fuel shutoff lever must now be used to stop the engine. IMHO this is a better, more reliable and fault tolerant setup for a mechanical diesel. I don’t know if there is an energise-to-stop solenoid available for these engines but that is another option if wired to a momentary switch to turn off the engine. I wouldn’t even consider a 24 volt solenoid on a 12 volt boat. There’s nothing to like about that.

Vesa Ikonen

Hi Kevin.
There is an energise-to-stop solenoid available for the beta 25 at least. Actually, at least with the panel I have, it is the default. There is a momentary switch that is used to stop the engine.
I learned that there is also a manual stop lever on the engine in case the switch or solenoid fails. The battery negative cable got loose, and it took me a while reading the manual at the middle of the night to figure out how to switch off the engine.
Have been very happy with the small beta, quiet and very reliable.

Kevin MacDonald

I think all the marine and industrial diesels are good. It’s all about finding the best fit for the boat it’s going in. Knowing how they work goes a long way in fixing any issues that will arise. There are plenty of ranches and farms in florida that run irrigation pumps with Perkins diesels 24 X 7 for years, only stopping for the long overdue oil changes. They are in a lot of tractors also and parts may be available from the tractor dealers. Massey Ferguson uses or used them it a lot of their tractors. The high revving Yanmars are fine in pleasure sailboats and will most certainly rust out before wearing out. It’s the peripheral equipment that goes bad unless there is serious overheat issues that go unaddressed. If you want more torque, just increase the reduction ratio. (torque multiplier)

Matthew Clark

Hi John, first, thank you for an amazing resource, it’s been a huge help in so many areas. How did you end up grounding the engine and thus the whole boat with the drive saver installation and have you been satisfied with the results and durability of the ground?

Matthew Clark

Ahhh, right. Do you feel the the strapping or brushes are reliable enough? I’ve seen so many electrical issues come down to intermittent / poorly connected grounds, just trying to weigh potential pros and cons of a drive saver. Thanks.