The Offshore Voyaging Reference Site

New Engine For “Morgan’s Cloud”—What We Chose

We decided that we wanted to stick with a simple machine without a turbo-charger or a controlling computer. And that we wanted an engine based on a block designed for commercial/industrial use, and to run for at least 10,000 hours without rebuild and with only routine maintenance—this is my third repower (two in this boat and one in the last) and I don’t want another before I retire from offshore sailing!

Finally, it had to be an engine that is available to our long time preferred boatyard, Billings Diesel and Marine, since we were not willing to get into this project with a yard we didn’t know.

The first thing we discovered when we started the search for our new engine was that there were very few choices available that met our criteria. This is at least partly due to new emission controls, which are most easily met by higher revving engines with common-rail computer controlled fuel systems.

Our first choice was a John Deere 4045D, a four cylinder 4.5 litre 80 HP engine with a reputation for reliability. However, the Deer’s mounting points are substantially wider set than the existing beds in Morgan’s Cloud. I’m sure that Billings could have modified the boat to accommodate the engine, but it would have been expensive and access to the lower parts of the engine would not have been good.

The envelope, please.

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David Head

I am certain that you will be more than pleased with this choice. I feel a little vindicated as my prediction was for the JD4045. Shame that the feet spacing was an issue. Is there no way that a manual override cannot be arranged for the fuel solenoid? I cannot believe that with the vast number of these engines being sold worldwide that a manual kill is not readily available or adaptable. Other engines I have experience of, in particular Yanmar, use a spring device in a sliding slot thus allowing manual override even when the solenoid is still energised.


Hi David,

Yes, I agree, there should be a way to run and stop the engine without the whole solenoid and inverter rig. I have asked the distributor to get with Sabre and see if they can come up with something. It will be a good test of manufacturer responsiveness too.

The problem is that, based on only a few minutes investigation, it looks to me as if the solenoid is energize-to-run and there is no evidence on the fuel pump of any mechanical lever to do the same job, like there was on the Cummins.

PS. If it had not been for the size of the Deere, you would have had the prize!


None of your cons bother me except the last one…I would be livid enough with this one to insist on a much more currently manufactured engine or at least a significant discount on the price of the one you now have…They should have made you aware of this before sending it to you and given you the option of it with the significant discount or full price for one of current manufacture…My experience is that only Yanmar is free of the maddening attitude that they are doing me a favor by allowing me to avail myself of their product under any circumstances…I hope this works out well for you anyway as I’m sure by now you are already well into the new installation..


Hi Richard,

Yes, we were disappointed too. However, the distributor has confirmed that the warranty will start from the in service date. While undesirable, I suspect that after the recent recession there are a lot of older engines sitting in dealer inventory that were bought before the melt down. Rest assured that if we have any problems with dried out seals, or the like, due to the age of the engine, we will hold Perkins/Sabre’s hand to the fire for a fix on their dime.


I recently did a delivery from San Diego to Costa Rico on a sportfisherman powered by two new MAN common rail engines with the same lovely automatic solenoid that must be activated in order for the engines to run. Result— diode failure in the charging system- voltage drops below 24 volts— and you are now adrift without power. The boat was wired with no crossover to the house bank and no way to charge the engine bank except through the 110v charger.
So before I go to sea again with any “modern” power train engineered by landlubbers i will have a spare solenoid or a way to mechanically bypass the shut off valve.


Good choice. Perkins has been around forever in this world, so it shouldn’t be hard to find parts or skilled mechanics wherever you are. Congratulations and good luck. I also agree to stay away from a lot of electronics and turbos when it comes to marine environments. Take care out there.

vince bossley

Pleased to see you have chosen a Perkins. Their track record is second to none and you can get them serviced anywhere in the world – along with generally, good availability of parts. I had a venerable (1988) marinised (Spanish) 4108 in my Ron Holland 43 which gave undying service.
Even after overheating mid Atlantic and setting off the powder fire extinguisher, I was able to run her when needed at 1200 rpm for the rest of the crossing without damage. At 9000hrs I replaced the bearings in Auckland (1999) and she is still running good as ever today.
Good choice and good luck.


I have a coupple of questions regarding engine selection on an older boat.

First question:
I heard good things from a trusted diesel mechanic about the engines from Beta Marine Engines ( So when I some time later was contemplating buying a boat that would need an engine replacement as part of the CE certification process, did I call Beta for info and pricing. According to the Beta rep is this engine designed specially for low rev low load and they meet the very stringent CE emission targets also on naturally aspirated Beta engines. The pricing was comparable to Yanmar (the other favourite engine brand of my diesel mechanic friend).

Is this an engine you are familiar with, and do you have any insight to share?

Second queston:
A boat I am thinking at trading upto now has been mothballed for a decade or more since completion. The engine is a Gardener 6LXB with only a few hours on the clock. The boat is already in Europe, so an engine replacement for CE certification purposes is not necessary. Do you think it would be worth while to, if the seals etc are dryed and useless, to have this engine rebuilt, or would I be better off replacing the engine altoghether with something new and wonderfully modern?

Alan S

Hi John, I was having a re-read of this old posting and noted your comment about Kubota vs Yanmar. In fact the Yanmar base engines for the marine GY, JH and LH series are all derived from their TN series industrial range, eg the 4JH4/5 engines Dick Stevenson & I have in our respective yachts are based on the 4TNV88 engine (the 88 signifies the bore in mm).
Similarly the turbocharged JH range is based on the 4TNV84 series, with an 84 mm bore.
Some of the industrial features include the 2 oil fill points and a dip stick low down beside the oil fliter on the JH. The latter on the marine engine has its handle cut off and instead we have the long stick tapped into what was the sump plug, making fitting a sump pump a bit of a mission
The larger Yanmars used in power boats have their basic engines sourced from a number of OEM suppliers, principally Toyota but also BMW & Scania

Victor Raymond

Hello John
We have the Perkins 4-236 on our new old boat. Not sure how many hours are on the engine since the tach has no Hobbs meter. However this engine purrs along more reliably than most cats and will propel the boat at 9 kts at 1400 rpm. That is too fast for me so I usually run it at less than 1000 and I increase the electrical load so the engine works a little.
The previous owner used 15w-40 but I think a straight 40 weight oil would have less detergent and better for an older engine. Any thoughts on that subject?
Thank you in advance.


Hi victor.
Well I,m not an oil-expert but I have some experiance of engines. First, check inside your valve cover, how does that look? 1) a lot of ” mayo looking coating” = lack of detergent. Buy some ship multigrade and wash (run the engine) the engine with it for some hours and then drain it. A straight 40 or 30 oil are fine if your engine runs hot. When I was racing cars in the older days I used a straight 40 oil. Today on my boat I run a modern multigrade 10/w30 with all additives modern oil has. I do change oil often ,,,,,,probably to often but what a heck it,s for the boat and when I look under valve cover and the valve-train it look clean and golden brown,,,No thick Mayo deposit. My opinion is that todays multigrade oil does not hurt old engines,,,mine is 30 years and overhauled once 1994, still runs fine. In todays heavy duty diesel engines in the trucking industry they use Mobil 1 synthetic….and now we talking power of 400 – 750 hp. Another thought is that carbon built up on the piston and piston rings are very harmful and will polishing the cylinder liners and will eventually cause a seized up engine. The reason is that the cylinder liner get to glossy and polished so the oil film cannot stick to the wall. A lot of carbon built up on the piston rings hurts too. The sign for that is blue exaust and high oil consumption plus a lot of “blow by”. My conclusion is, do not be afraid of multigrade oils in old engines.


You are right never be to gentle to a combustion engine. An engine should run at least in the range of 75-90% of it maximum power most of the time. Running to cold on part load create carbon built up. Always strive to have a complete combustion as possible to avoid unburned HC in the exhaust. Once in the while stress it to max power for a time.. The most important is the operation temp of the enginge , do not let and an engine run cold like 60 C what is most likelely in older days when they used sea water. Todays engines use heat exchangers and internal cooling system with antifreeze which is very good for a lifetime of a marine engine,,,the higher temp the better regarding wear,,,use a thermostate around 90 -95C that will minimize wear and tear . The worst case for an engine regarding wear and tear is ” cold starts” that really hurts on bearing, cylinder liners and pistons I would say all moving parts in an engine. An engine who have a lot of cold starts increase the wear dramatically. So there is a reason why truckers and other big vessel never shut the engine off..they would like to keep the temperature of the engine .
Happy sailing to you all!,,, I’m currently moored in Grimstad Norway.

Victor Raymond

Dear John and Conny
I am sorry to appear rude to not acknowledge your responses to my submission. I have been offline while sailing in the San Juans for a few days before my refit starts.
All your points are very well taken and I will follow through with them shortly. Before my refit I plan to drain and replace the oil and filter then replacing the oil after refit is complete .
John, I think you are right on about the tach being screwy. When I push the throttle a bit past 1400 it reaches it’s limit so that leaves me to believe 1400 is more like 2200-2400 rpm. This is all good news because it means I was not really running the engine at 800 rpm but probably closer to 1200 and fuel burn less than one gph.
In any case a lot to be uncovered and resolved before another long passage.
Thank you both again for your sage advice and suggestions.
now if I can only find a good engine mechanic comparable to Brion Toss for rigging and Carol Hasse for sails. Wow, these two are amazing.


If you are in the Seattle/Port Townsend area can I recommend Pat’s Marine Engines located just past the Ballard Bridge in the ship’s channel between Salmon Bay and Lake Union in Seattle. (206) 285-0184 – .

Two years ago Pat’s Marine Engines installed a new Yanmar and shaft seal on my 34 foot cutter, and did a very tidy job that left me with easy access to all engine service points.

Pat’s Marine Engines does not come cheap, and they work only by the hour so estimates are only estimates. In my case did they go 25% or so over the given estimate. Still worth it and I would use them again if I buy a larger boat, even if outside the Seattle area, as they are willing to travel. (I have been burned a few times by smooth talking assholes, so when I find a good shipwright, diesel mechanic, or sailmaker, do I stick to him/her.)

Sailmaker: Schattauer Sails 206-783-2400 in Seattle. Made beautifully artisan crafted new sails that fully complied with my wishes of UV protected cloth and battenless main (my boom is longer than standard, so the loss from the missing roach is covered by the longer foot.) Also not cheap, but to me worth it.

Victor Raymond

Thank you Eva, I will look them up. I am looking for some honest mechanics not ones who try and sell you a new engine just because yours has a few hours on it (read 6,000) plus.

What they don’t consider is that I have enough spares to replace every major component on the engine less the cylinders themselves, that engines starts faster than a person can release the starter switch after turning it, and that newer engines while they come with warranty will not help me much until I am somewhere near a dealer.

So unless proven foolhardy I will stick with what I have.

Thanks again for your recommendation.


I bought the engine from the MER Equipment, the Yanmar dealer in Seattle, before contacting Pat’s Marine Engines about installing it. Pat never mentioned to me that it might have been advatageous for me to buy the engine through him before the engine I already had bought was in place. This annoyed me at the time, but seen in retrospect is this indicative of Pat’s discretion. I now use Pat as a sounding board on the existing engines in the somewhat larger boats I am considering moving into. Plain good advise, not salesmanship. To call him pushy is to wrong him.


Hi John

Need some advice here. I just bought a 44 fiberglass boat in Singapore that comes with a Yanmar 4JH-HTE (turbo with intercooler) 1986 which was rebuild in 2003 in Fort Lauderdale. The clock shows 3,300 hours.

I will be living aboard with my wife next couple of months and plans to take the boat to Indonesia and Indian Ocean for diving and if time, money and passion permits , a journey further away.

I am considering of taking out the turbo and intercooler unit to make the engine a simple aspirated engine with some loss of power at top end. I will be cruising most of the time at 2,400 rpms.

What do you think of this conversion?

If I were to take out the turbo and intercooler, what else do I have to replace ie injctor pumps? The Yanmar people in Singapore were not helpful as they say nobody does this this thing.

Any suggestions and advice?



Rob Bordner

I am looking to repower an old Perkins 4-154. The boat is a Metalu Jade 48′ aluminum ketch, center cockpit, plenty of room. The M92B would be perfect, but the problem is that I cannot get one in North America at this point. Would you have a recommendation? One option is to re-power with a remanufactured 4-236 – OR – wait, take my chances, and re-power when I get to New Zealand? Thoughts?! Rob S/V Athanor, Seattle, WA

ste nautique amure et vent

prix du moteur perkins M92B livraison a faire a st Mandrier
var France

Alan Bradley

This is late in coming, but it seems like the most appropriate post to ask an engine question. After reading all you’ve written about your re-power and about the desirability of low-rev, industrial block diesel engines, I still have to live with my fairly new (1200 hours) 2008, 54 hp, naturally aspirated Yanmar 4JH4AE in my Caliber 40 LRC.

I did take a look at the power curves for my engine after reading your posts, and lo and behold, I figured out I had been doing things all wrong. (This is my first boat.) I had always heard that “diesel engines like to be run hard” and proper loading was very important to engine longevity. Consequently, I always tried to run my (3000 rpm redline) engine at about 75% power, 2200-2400 rpm. BUT, the power curves showed me something different. The best range for torque and fuel efficiency was more like 1800 rpm.

Since changing to a new cruising speed of 1600-1800 rpm, I have lost only a little bit of speed and gained a huge amount of fuel economy. I have gone from close to 1.5 gal/hr at 2400 rpm to 0.6 gal/hour at 1800 rpm.

I still hear people saying all the time how their trusted diesel mechanics always want them to run the engines hard or at least to run them hard for the last 5 to 10 minutes before shutting them down to burn off any carbon deposits on the valves/pistons from running at lower rpm’s.

My question is… What do your trusted diesel mechanics at Billings Diesel & Marine have to say on this subject? I really don’t want to give up this great fuel economy. Am I hurting my engine in the long run? Should I “run her hard for 5 minutes” before shutting down?

Please feel free to edit this long question and still help me and any others who have always heard the same advice.


Eric Klem

Hi Alan,

I can’t speak for John or Billings but here are a couple of my own thoughts on this.

Engines will typically be most efficient at wide open throttle at the RPM corresponding with the torque peak. The limiting factors on power output from the engine’s standpoint are the cylinder pressure and the ability to dissipate heat. In general, an engine will have constant cylinder pressure at WOT across most of the rev band because this is what determines the loads on head bolts, con rods, wrist pins, cranks, etc. If the efficiency were the same, this would mean that torque would be constant (this is a bit of a simplification but not too far off) across the entire band. Because the efficiency is not the same, the engine will produce the most torque at the rpm with the least losses. However, when you need less power, the most efficient rpm will be lower. The most efficient operating point will lie somewhere between idle and your torque peak rpm depending on the power output required. Of course, you can’t actually pick how hard you load the engine in a sailboat unless you use a controllable pitch propeller or some form of multi-speed transmission. If you really want to analyze all of this, you need to look at the “fuel island plot” for your specific engine but they are usually only available to the engineers.

The other important thing is the load on the engine. As you approach hull speed, the required power goes way up and you will necessarily burn a lot more fuel independent of engine efficiency. Many people confuse power and torque so make sure you are clear on that.

So the real question is then, will it hurt the engine to run it at these lower speeds and loads. First, it is important to note that many people talk about running at 70% or 80% load when they in fact mean speed because the load falls off much faster than the speed (it is often closer to 50% load at these speeds). Of course, the answer to how hard you need to run the engine depends because all engine designs are different but you can make some generalities.

Engines typically wear out by loss of compression. Ring wear is proportional to the cylinder pressure and the ring velocity so running your engine less hard and at a slower rpm is better. Actually, one of the best predictors of engine life is the total amount of fuel burned because it is proportional to the PV for the rings. You don’t want to go overboard with running the engine lightly because there are problems related to thermal growth (definitely get the engine up to temp) and carbon deposits. I haven’t done a scientific study of this but my gut reaction is that with an appropriately sized engine spinning a reasonably pitched prop, running at your torque peak rpm or higher is probably just fine. If you want to start to push the limits on this, I highly recommend some extra instrumentation such as exhaust gas temperature (EGT).

The only caution that I would have with running the engine hard just before shut down is if the engine has a turbo which I realize yours does not, you need to let the turbo cool down. The best way to do this is to monitor EGT and make sure that it is below 300F or so. The consequence of not doing this is cooking the oil inside your turbo after shutting down because it won’t be flowing anymore.

I hope that his helps.


Alan Bradley

Thanks for taking the time to explain things so clearly. I’m going to have to revisit those power curves to make sure I’m doing this correctly.
Thanks, Alan

Marc Dacey

Eric, thanks for this. You are further convincing me that EGT sensing of some sort would make a valuable diagnostic tool for us in order to balance the desire to reach peak fuel economy while limiting engine wear as much as possible.

We have a four-bladed feathering Variprop on a Beta 60 set to the nominal “factory pitch” of 19 x 15 in forward. I intend to see if I can increase the pitch in reverse for stopping/maneuvering power and flatten it a bit in forward for economical motoring and range extension. Assuming I have the means to measure my fuel usage, would you suggest that the installation of an EGT would give me the data I need to effectively “profile” my engine’s loads properly? Thank you. Again, an example of the vast amount of knowledge on this site.

Eric Klem

Hi Marc,

John’s reply is absolutely right.

Overpropping is an interesting subject. If you can just reach max rpm at WOT, you will generally get the maximum power out of the engine. This is really helpful when punching into head seas or something like that. If you are willing to give up some of this max power, you can increase the pitch a bit and more heavily load the engine at lower rpm improving fuel economy for the same boat speed. This is a real tradeoff and one where I personally prefer to keep the prop close to “correctly pitched”. If you do overprop a lot, watching EGT is really important. Many smart people have weighed in on this subject including John in another post and Steve Dashew (who overprops slightly).

EGT is a number that engineers and performance engine builders love but is largely meaningless to the average person as you need to have more information about the engine than is publicly available unless you are simply trying to avoid burning up pistons. On our boat, we do not have an EGT gauge and I don’t think twice about it because we are only slightly overpropped. I used to do a bit of performance engine work (I have grown up from this thankfully) and I used EGT probes all the time in that but we were pushing the envelope a lot and we had a lot of other instrumentation as well. The only reason that I would want one in a small sailboat is if I could vary the load on the engine through gear ratios or prop pitch. One note that I realized that I haven’t mentioned is that on a turbocharged engine, there is a big difference in whether the EGT probe is before or after the turbo.

I am looking forward to Matt’s series on this subject.


Conny Harlin

Hi Eric.
Here are some thoughts and experience from me.
I would recommend to increase the prop diameter instead of pitch in order to increase the load on a marine engine in a displacement boat. The reason is that you will gain better grip/bite (less slip)in the media water. This will keep your speed much better in rough seas,the reason is increased prop surface exposed to water.Pitch should only match the boat speed through the water, over pitched prop will increase cavitation and loose grip. Why have a pitch for a speed of 12 knots when your boat only is capable and design for a speed of 6- 7 knots??? The trade-off in Diameter is really noticeable in heavy seas and handling in harbors. Above is what I have done on mine boat and happy with,,,I have 7,5 -8 ton sailboat with a 23hp/2400rpm engine, gear ratio 1,61:1,, Prop 17″x9″. With this set up I go 6 knots at 1650rpm, Max rpm with this prop is now 2200 vs 2400 rpm,, A test is to borrow a dynameter and measure the propulsion at different rpm at the doc with either larger diam vs increased pitch.

Good Luck

Conny Harlin

OK,,Got you. I thought the pitch was set right for this boat speed. Regarding increase diameter,,,keep in mind to have at least 2″ distance or greater to the hull from the tip of the prop to avoid noise and vibration in the hull.
Fair winds guys // Conny

Alan Bradley

Hi John,
Here are the specs on our 2008 Caliber 40LRC:
LOA 40’11”
LOH 39’1″
LWL 32’6″
Beam 12’8″
Draft 5’5″
Displacement 21,600 Lbs
Ballast 9,500 Lbs
Of course, with a 212 Gal fuel capacity and 165 Gal water capacity, a dive compressor, small diesel generator, a bunch of tools and spares, and all the stuff that two full-time, live-aboard cruisers and cram onto a boat, I can’t even guess what she really weighs.
Thanks, Alan

Alan Bradley

Hi John,

Sorry for the delay; it’s often a challenge finding a good internet connection while cruising in Mexico.

No need to apologize for the additional questions. I should have thought to include the transmission and prop specs, since we are talking about propulsion after all!
Transmission – 2:33.1
Prop – Original from factory, fixed, 3-blade, 17R13

I remembered a couple more things after re-reading a lot of the comments on this thread: I did always have that “exhaust halo” back when I was running at 2400 rpm; and I have no problem reaching the specified 3000 rpm with even a bit of throttle left to go.

I’ll be looking forward to the new posts from you and from Matt.

Thanks, Alan

Bob Muir

Link to Matt’s theory post?

Adam Kerner

Hi all. We are currently planning the build of a new Boreal 52. I’ve read with interest the story of the Morgans Cloud repower, and the discussions of engine evaluations. Engine choice for the new boat is proving to be a challenge, and perhaps some on this site can offer some insight. The “standard” engine offered by Boreal is a Volvo D2-75. A common enough engine. However, I would really like to steer clear of Volvo for reasons primarily dealing with service and parts availability. Outside of Europe it can be a real challenge. Also, the D2-75 is the same basic engine as the D2-55, just w/ added turbo and a few other tricks to tweak the HP and torque. Not my preference. It’s often used in raceboats where it’s really just to get out to the start line, charge batteries, and perhaps get back to a safe harbor. Many of the Volvo race boats use them for that reason, (oh, yeah…’s called “Volvo” for a reason!) buts its a very different use than ours. The only other engine that Boreal has identified which will fit is a Yanmar, but unfortunately in the larger sizes these are now all common rail, which I also aim to steer clear of. Problems with fuel in remote parts of the world where we cruise just don’t seem compatible with the injection pressures seen in common rail design.

I’ve spoken with Boreal about other options, such as the Perkins, Beta, etc but all are too heavy / large to fit into the boat.

So, given these two choices: a Volvo D2-75 or a Yanmar 80 w/ common rail, which would you recommend and why? (I’m not thrilled with either one!). Do you have any other engines that we should look at?? For example, I’ve been reading about the Vetus VH4.80 as a possible option. Seems light enough, but WOT is 4000 rpm…..yikes! Based on a Hyundai truck engine, but I don’t know much about them. The Volvo and Yanmar are both in the low 200kg range, so that seems to be the goal. Your thoughts?

Marc Dacey

I installed a Beta 60 naturally aspirated engine on this basis and I believe it’s an M2 (but please confirm that). I am slightly adjusting my feathering prop to get into the most econommical zone for cruising, plus the most torquey zone for reverse (it’s a metal boat and when we wish to stop or back down, it’s rarely gradually). The Beta/Kubota blocks are simple to service and the parts, cross-referenced to the tractor/construction vehicle Kubota numbers, are cheaper than anything else with the word “marine” on it. We are very pleased to date with our choice, which was right for our boat, but I can certainly see the same or an even smaller Beta (like the 50 HP) in your Boreal. You may wish to consider soft engine mounts and a CV joint/thrust bearing, which would be considerably easier to spec in the build process than afterwards. People stepping aboard sometimes can’t tell the diesel is idling on our boat, which is a nice thing to experience.

Adam Kerner

Good one, Marc. Nice to hear that the Beta 60 is working well for you. I can’t recall what design your boat is??? Would be interesting to see it, as well as the displacement and WL specs. What performance #’s are you seeing at cruising rpm? I see above that you’re using a 4 blade Variprop. We have this same prop on our current boat (Kelly Peterson 46), married to our Yanmar 4JH4-TE (75 HP). It’s been an excellent combination.

I do like the Beta’s. As said below, Boreal has looked at them in the past without success, but they have said they will take another look now. Will see what they decide.


Marc Dacey

Adam, our boat is a custom full-keeler motorsailer displacing at light load (full fuel, no water and few stores) 29,500 pounds in the slings. The WL is a modest 31 feet, meaning a hull speed limitation of 7.3 knots (although I usually motor around six knots and we’ve sailed in the high sevens), which we can achieve at present at 2,100 RPM out of a total of 2,700 RPM at wide-open throttle. This suggests that the forward “stops” on the four-bladed Variprop (which we love, by the way, and which helps us do far tighter maneuvering than our appearance suggests) are, at 19 inch width by 15 inch pitch, could be flattened slightly in forward to get to hull speed at 2,250 RPM, which would put us more on the sweet spot for economy for motoring. I hesitate to do this, however, until we have full cruising load on and the boat is fully on her lines. So there are a few things to consider. The Beta 60 is not very wide to my eye, and we got it with a shallow sump because I was not sure before we’d zeroed in the stringers if I could take the deep one. My blog has a great deal of photos and commentary about its installation you may find helpful. I do not resent commenting that the Boreal 52 would be undoubtedly easier driven than my Land Rover-like boat, and that driving a Beta 60 at 75-80% would be a good solution unless you anticipate “parasitic” loads from ambitiously sized alternators. Good luck with your solution. My Beta 60 cost me about $11,500 Canadian in 2012.

Adam Kerner

Thanks for this, John. I have asked about the Beta, but was told that they’ve looked at it in the past, and it was too wide to fit down into the keel box. They will check again, but I don’t want to shoehorn an engine that just marginally fits. That said, I really do like the Beta’s, and think the 70 would be a good engine for us.

It is a difficult decision, as the new emissions regulations have really narrowed down the choices, especially in these larger sailboat sizes, and are forcing us to go in the direction of common rail, which I believe are the wrong tool for the job of voyaging boats. Time may prove me wrong on this, but for now, I don’t want to risk it.

Carl E.

Hi Adam,

I don’t know whether the 52 has a smaller engine bay than the 55, but according to Colin’s report of the 55:

…a 55 was fitted with a:

“French-made Nanni N4-85hp based on the highly-respected Kubota motor”. Going by John’s reply, that may be overkill, but would the 52 be able to fit the Nanni?

Adam Kerner

Hi Carl
You’re right, Eala Bhan does have the Nanni fitted happily to a MaxProp, and they have been happy with it to date. Unfortunately Boreal has had several bad experiences w/ Nanni’s, and don’t want to go down that road again. Even though both are based on a Kubota engine, the Nanni appears about 3 inches narrower overall than the smaller HP Beta when I compare their drawings. They must be using a different Kubota base engine.

Marc Dacey

Yes, although you pay in diesel when you run WOT, I have heard the same thing. That and the comparative mechanical simplicity and the huge range of customizations (we have a dual PTO, a shallow sump, a remotely mounted oil filter, “soft” mounts and a ZF hydraulic transmission, for instance, were compelling arguments in favour of Beta. Others that don’t apply to people who have a 360 degree engine bay include the logical placement of and access to “consumables” near the front of the engine. I’ve seen nothing to date that I have to pussyfoot one bit and if I’m being chased through a narrow seawall by a big stern wave, I do not hesitate to “floor it” to get inside with authority.

Adam Kerner

Thanks, all. I’ve asked Boreal to have another look at possible options from Beta. I like the way it sounds as though Beta may have some customization options up its sleeve to allow for challenging fits. Hope to get it figured out soon. Cheers!

Rob Gill

Hi Adam,
We own a Beneteau 473 (14.5 m) which in cruising mode has a displacement of around 14 Tonne. From new she has had a Volvo D2-55hp diesel which was the Perkins engine – it’s even got a “made by Perkins” plate on the rear of the block.
We run a single Mastervolt 130 AMP alternator rated at 5HP when fully loaded, with a soft override switch to shut down the alternator if we need all the engine power and torque for the propellor (say in rough head-seas). A three bladed Maxprop gives great grip ahead and good response in astern with only moderate prop walk. Being naturally aspirated, the engine has been extremely reliable and we can motor in good sea conditions at 8.5 knots (hull speed is about 8.7k), cruising at 6.5 knots at about half revs. In cruise mode, we use about 2.3 litres of fuel per hour. The engine service interval is annual or 400 hours which is fine for offshore work.
If your 52 is significantly heavier and you feel you do need the turbo power, based on what we hear in the Pacific the Yanmar is the more reliable of the two. Three friends with B473 have had either Yanmar 75 or 110s fitted. Interestingly, although each owner has been happy with their Yanmar engine, none have been faster under engine that our Volvo 55Hp.
The bigger Volvo Turbos don’t have so good a reputation, labelled unkindly as “green death” by some, but I have no first hand experience of this.
Based on the above, I would be very happy with the Volvo 55 or Yanmar 75 – I think there may be some (potentially serious) unintended consequences in trying to shoehorn a bigger engine block into a small engine bay. I would go with what has been proven before by the builder, especially if you are going to extreme latitudes. John wrote an excellent article on not pimping up your engine and I feel your situation has a few parallels.
Either way I am sure you will have a great boat.

Adam Kerner

Hi Rob. Thanks for this. I agree with you about shoehorning too big an engine into the engine space. It’s bound to lead to access issues down the road. And unlike some manufacturers, Boreal smartly requires that all engines can be removed from the boat down the road if necessary

It sounds like you’ve got an excellent match of your boat to your D2-55. In “wet” cruising trim, the Boreal 52 has a displacement of 19.8 tonnes. Though they use your D2-55 on the 44 and 47, they go to the D2-75 as their “standard” engine on the 52 and 55. I agree with you about the reputation of this engine…..not at all good. The turbo’ed Yanmar 75, the 4JH4-TE is much better regarded. I installed this engine on our current boat about 12 years ago, and have been happy with it’s record for us over the 2000 hours since. I’d be ok going this route again, but this engine is now only available for repowers, not for new builds in Europe due to environmental regulations. The replacement of it’s HP size is the 80, which is common rail, as is the 110HP.

I would agree with you about going with the builder’s “standard”, as I obviously think highly of Boreal’s design expertise. However, in this case, there are not too many of the 52/55 series to look at. I’m not sure how many have been built with any time yet “out there”, but fewer than 6 or 8, I’d guess. Far fewer than the 44/47’s. Of those, I now know of one with the Volvo D2-75, one with the Nanni, and one with a 110, Yanmar, I think. So it’s tough to get a meaningful consensus of opinion yet. You take Nanni out of the equation, and I prefer to stay away from the D2-75, and the only available Yanmars are now common rail, and it is a limited field indeed. Perhaps a smaller Beta than they’ve previously looked at, like John suggests could fit. That would likely mean the 60 or the next smaller, the 50. I know most install over sized beasts on sailboats, but I’m just not sure how small I can go and still have the requisite grunt to power into head wind and seas when needed on occasion. Cheers!

Bruce Bayne

Some really great information in these posts! Enough to cause me to put fingers to keyboard and ask a few questions on repowering.

First the specs:
Boat: 1980 Fast Passage 39
LOA: 39.5′
LWL: 33.5′
Beam: 11.83′
Draft: 5.5′
Displacement: 21,000 lb. Weighed 25,000 lb on last haulout, so I would consider about 26,000 ready to cruise.
Engine: Perkins 4.108
Transmission: Velvet Drive 1.91:1
Prop: MaxProp 3-blade 16″. I’ve played with multiple pitches and now am a bit over pitched.
Alternator: Balmar 94-12-210 with serpentine 6-groove belt. For reference as to drain on the HP of the engine.

I’m looking to repower as I’m not confident in the engine. Our last trip we burned 1.25 gal of oil in approximately 100 hours. No heavy smoke from the exhaust, just light gray that is sometimes almost invisible. I had a very reputable mechanic take a look an he thought the engine seemed quite good, and couldn’t for the life of him, understand where the oil was going. He had an oil analysis done and it indicated some metals in the oil, which was of concern. I did a compression test and found #1 was lower than the rest of the cylinders, so did a leak-down test on #1 and found leaking through the intake valve, so did a head rebuild. It’s still too early to tell if this has had an impact, as I just finished the hot engine torque down of the head bolts. Over the next several weeks I’ll do a trip to see if I’m burning oil at the rate I was previously. If I am, a repower is in my future.

Since I’m in the research stage of this I’ve focused exclusively on Beta Marine engines. My posts with the US distributor has them stating that either the Beta 38 or Beta 43 would be the best options. I’m not liking the Beta 38 as it is a 3600 rpm engine (they want to put a 2.45:1 transmission on it) vs. the Beta 43 which is a 2800 rpm engine. After all the AAC reading I’ve done, you have me paranoid about high revving engines. I know there’s a bit more to it than that, but suffice to say I’d rather have a lower revving engine based on the posts and comments here.

The people at Beta have been quite good at answering my questions and making suggestions as to size of engine, prop size, and gear ratios. One issue they are struggling with is that I can’t fit a larger prop than the 16″ one I currently have, and most of their calculations are calling for a larger prop. There just isn’t much room above the prop for anything larger. I also have your prop tip speed calculator and am wary of spinning the prop too fast.

The latest feedback from Beta has been a Beta 43 bobtail with a Velvet Drive kit so I could move my current transmission to the new engine, after a rebuild of the transmission. According to their calculations this would give me a configuration that would efficiently spin a 16″ prop.

They also have a smaller Beta 35 that I haven’t had any conversation with Beta about. Knowing that you like bucking the inclination to go up in horsepower, I figured I’d throw this one into the mix as well. 🙂

Any feedback would be greatly appreciated and if I’m missing any info, please don’t hesitate to ask.

Thanks for putting all the effort you do into this site. It’s a wealth of knowledge that I find very useful.

Bruce Bayne


Good point on the transmission. My problem is that none of the transmission options are available with 1.91:1 ratio. I can get close with a 1.96:1 ration that jumps the spec to a 17″ propeller. I guess I could pitch my 16″ a bit more and suffer with a bit of a loss on prop efficiency. I’m not sure how much that matters though. Thoughts?

Patrick FitzGerald

We recently installed an M92B in our boat and it purrs like a kitten . . . that is until it is revved over 1800rpm at which point it produces copius amounts of white smoke which seems to be unburnt fuel. The local diesel mechanic cannot seem to deduce the problem and several inquiries to Perkins have gone unanswered. Have you ever heard of or experience a similar problem with the M92B? Could you suggest someone who might be more familiar with this engine?

Patrick FitzGerald

Thanks for the suggestions John. Ours is a new installation with less than 20 hours on the engine. As I mentioned it runs quite smoothly under 1800 rpm with no visible smoke after startup. It is far quieter than the 80’s era Detroit 353 that we removed. I think that you may be onto something regarding the injector pump. Our new M92B had to be largely disassembled in order to fit through the companionway hatch and was put back together by a yard that had limited knowledge of anything other than Yanmars. We subsequently moved the boat to another yard and found a more capable mechanic to complete the install but he has run all of the usual tests and has been unable to find the source of the white smoke. He has checked the injectors but says there is no way to adjust the pump timing so perhaps it was reinstalled incorrectly. There seems to be no one I can talk to at Perkins (why is that?) so I will talk to Caterpillar next to see what they suggest. We’re on the Delaware, just north of Philadelphia, so I’m sure there are some capable Cat mechanics there. Thanks for the insights.