Boating and fuel cost

[Marin]

Most things are designed to take advantage of the best technology available at the time. In the 1950s, when the Ford of England diesel (Dover model) that became the base engine for the Ford Lehman 120 was designed, jerk-injection fuel pumps (the Simms pump) and single-weight oils were considered the best technology at that time. Also, relatively low road speeds and lighter truck loads were the norm at that time.

However, both road speeds and truck loadings were going up rapidly during the later 50s and early 60s, which is why the Ford Dover proved to be an unsuitable and unsuccessful engine in over-the-road trucks.

So to build on Ken's comments, not only should the type of oil and type of fuel be considered when determining how best to operate an older engine, so should the manner in which it was intended to be operated when it was originally designed. Operating and maintaining an FL120 as though it was a more modern Cummins, John Deere, Volvo, Cat, etc. will simply result in the engine having a much shorter life. If you feed, operate, and maintain a 1950s engine as though it was the 1950s, you'll get the maximum possible life out of the engine, which for an FL120 is pretty long.

I believe this is harder to do with boats than it is with vehicles. Nobody expects a stock '55 Ford to perform like a 2007 Accura. The Ford doesn't even LOOK like it should perform the same way. But our 1973 Grand Banks 36 looks pretty much the same as the 1991 GB36 a few docks over. But where our GB36 has a couple of FL120s in it, the one on the other dock has a couple of Cummins Turbo 210s in it. If I tried to get the same kind of speeds and service intervals from our Fords, it's doubtful that our engines would get anywhere near the 12,000 to 14,000 hour life these engines have a reputation for.

-- Edited by Marin at 00:56, 2007-12-03

 

[Baker]

I'm gonna go along with 2buck. Go with what the manufacturer says. I have a car the "recommends" premium. It knows when it is not premium and actually remaps the fuel mixture and timing killing performance. Car computers are pretty darned smart these days. My engine also specifies Mobile One....but any other similar spec synthetic will do. The one thing synthetic ddoes do that dino oil does not is hold up over time. The oil in conjunction with it's filter is able to keep contaminants in suspension and filter them out whereas dino oil breaks down much quicker. If I used dino oil in my car and the engne failed I would most likely not get covered under warranty.

Now as it relates to boats....Cetane booster is most likely a waste of money for you Lehman guys.....not for me. My manufacturuer(Yanmar) specfies a minimum Cetane rating of 45....and as we all know, very rarely do you know or can you find out the cetane rating of the fuel you are putting in your tank. But when I do put it in, there is much less smoke, it idles much more smoothly and quietly...and I even think I get a little bit better economy. My engine is 213 cubic inches and puts out 240hp!!!

 

[Nomad Willy]

John,

What rpm does that Yanmar need to turn to make all that power? If it's not too noisy it must be sweet to run. I'm going to guess Yanmar specs Mobile oil because synthetics vary so much. Many are made from very different base stocks and have widely differently characteristics. Dino oil is the opposite. Very much the same. I'm sorry I said that about all boat engines needing straight 30 W Fortunately sometimes when I open my big mouth I learn new stuff. I think I'll still put Delo 30 in my new Mitsubushi ( over 100 cu. in. and less than 40 hp ) as it is almost no difference between it and the 33 yr old Perkins it replaced. Turned the same gearbox and prop only 80 rpm more. An interesting foot note on oil is that I think Subaru voids thier waranty if one uses 10-40 oil. Can anyone conferm this? Another foot note is that ( relative to my comments about gasoline and octane) is that diesel engines do benifit from higher cetane.

Eric Henning
30' Willard
Thorne Bay AK

 

[Baker]

Willy, sorry I was talking about my car when I was referring to synthetic oil.....not to my boat oil. Someone above had brought it up about cars and I was just answering along those lines....sorry bout that. I use (Rotella) 30wt just like you. The Yanmar turns 3100RPM continuous(190hp) and 3300RPM Max(1 hour and 240hp). It is a sweet running engine but it does make some noise. I think most of the noise is due to harmonic vibration in the hull. I think flexible engine mounts and couplings would eliminate a lot of that. Again, sorry about the misunderstanding.

 

[Nomad Willy]

John,

Your'e making over six times as much power as my Willard and probably weight less than half as much.Your engine is'nt even twice as large as mine...wow! I cruise mine at 2400 and max at 3000.
To make so much power it must a lot of heat. I'd think of going to 20-50W. What does Yanmar recomend? I don't envy you with a harmonic vibration. I fought that one for years. A lot of harmonics get blamed on propellers, shafts, mounts ect but I think much of it is in flat or nearly flat surfaces of the hull or bulkheads and cabin tops. If you need or want to fight it let me know. You should probably contact Mainship as they may have recently solved the problem if indeed it is that.

Eric Henning
30'Willard
Thorne Bay AK

 

[2bucks]

I know I'm resurrecting an old subject here, but the earth moved this month. Give me a minute to lay the foundation and then I'll tell you what I mean.

NomadWilly wrote: "My choice of boat was heavily influenced by seaworthyness, comfort and most importantly - fuel consumption. I wound up with a gallon an hour boat. One also needs to choose an engine that is small enough so the engine can be worked fairly hard if it is diesel. Steve DeAntoino of Passage Maker magazine ( technical editor ) says that one needs to work the engine at 75% load 75% of the time. He calls it the 75/75 rule. 75% load is determined by finding the engine speed that ones boat burns 75% of the fuel it burns at wide open throttle. Engine manufacturers or engine marineers ( such as Volvo and Cummins ) can usually tell you what the WOT burn rate is. I think the most common response to high fuel costs is to slow down. I shudder to think how many trawler yachts have diesel engines with serious problems ...even glazed cylinder walls from under loading. I choose an engine of only 37 hp and the boat only requires 18hp to cruise. I still am going to have trouble running it hard enough to comply with the 75/75 rule."

So with his 2 decades of experience Mr. D'Antonio has now changed his tune. 75/75 is no longer etched in stone as he would have had us believe last year. In the March 2009 issue of PMM Steve now says:

"Think of it this way: Running on two engines that are both operating at 30 percent load creates all of the aforementioned negative side effects of overcooling, carbon formation, sludge, and so on. On the other hand, running one of these engines at 60, 70, or 80 percent load eliminates or considerably reduces these detrimental effects."

"Perhaps of greater significance is the efficiency at which a diesel engine operates when heavily loaded. (snip.....) It therefore makes good sense to run one engine at 50-80 percent load rather than 2 engines at 30 or 40 percent load." (PMM vol 14 No. 2, Page 76 paragraphs 2 & 3)

Well, well, well. We've changed our tune and now admit that we don't have to "run 'em like we hate 'em". Maybe running easy is good for fuel economy AND longevity. It seems as if he now admits that 50% load doesn't cause rapid wear and failure.

The article also has many other points on keeping the bottom clean, keeping shafts aligned etc. which I think most of us are already keeping up on.

Ken

 

[Baker]

I seriously doubt there has ever been a catastrophic engine failure due to underloading??? I know my boat is never underloaded...

 

[RickB]

I believe it is difficult to "underload" a diesel which drives a fixed pitch propeller. We constantly see the results of low loading on generator engines, the same engines used as main propulsion engines on the trawlers we talk about on this forum. The problem arises from low loading at high rpm, a condition easily obtained on a generator but difficult to do driving a propeller.

My personal take on this "issue" is that DA and others have applied the generator problems to propulsion engines and created a straw man.

 

[Forkliftt]

The difference in economy at 6 knts vs 7 knts seems to be substantial on a boat my size. I generally run about 1600 RPM but may start dropping lower for the economics of it.Steve

 

[FF]

6 knts vs 7 knts seems to be substantia

The Sq root of the lwl times 1.15 and less is where the best fuel economy is, hull wise.

Weather your engine has any efficiency at all operating that slowly is a different question.

Best solved with a much lower HP engine working harder , but unless repowering no trawler would be used enough hours to pay for the difference , even if the fuel burn was reduced by 2/3.

 

[Nomad Willy]

****I'm with FF all the way on the oil changing issue. I run the boat specially for the oil change. Warm it up for 15-20min and then work it hard for 10 min* .. run back into the slip and pump it out ( the oil ). The filter can wait as settelment of sludge ect will not remain in the engine anyway. Marin, what do you mean " too hot to handle? ". With that upsidedown filter you probably get hot oil all over the place including your hands. Get a remote filter kit and mount it*on a bulkhead. After this discussion I think I'll run 30wt in the future.
*** Ken, Ill bet Steve DeAntonio thinks the same as in the past and put that comment about 50% loading in there because of all the flak and stuborness he undoubtedly recieved from old trawler guys unwilling to accept his platform. I agree with Baker and others that there seems to be little evedence that running light is harmfull. Per Sunchaser I also agree ( and to a greater extent ) that if one gets the lube oil up to 190-220 degrees there should be no problem.
*** Marin, that Northern Lights guy really needs to know about radial tires.

-- Edited by nomadwilly at 13:55, 2009-02-11

 

[RickB]

"... much lower HP engine working harder ..."

Not necessarily ... like someone else said, it takes X hp to move Y weight Z distance in T time. The premise of the argument for smaller engines is that generally a diesel engine has a lower brake specific fuel consumption (BSFC) at an output not too far down from its maximum rated power. The reality is often quite different when comparing large engines to small engines*as smaller engines generally burn more fuel to produce the same power and return a higher BSFC*than a larger engine.

For instance, let's take a trawler that was delivered with a Cummins
4B155B 4 cylinder turbocharged engine that produces 155hp at 2800 rpm. The owner finds that the boat runs best at around 2250 rpm which (according to Cummins) equates to 80hp and burns 4 gph.

If money were no object, and all we wanted to do was try to be as efficient as possible by following the advice to go to a smaller engine and work it harder, we could replace the Cummins with a Deere 4 cylinder turbo'ed engine rated*for 100hp at 2400 rpm and run it at 80hp in accordance with the "rule of thumb." According to Deere figures, that engine would burn around 4.7 gph to provide the same boat performance as the Cummins.

As the old internet saying goes, your mileage may vary but physics is physics and diesels don't read boating magazines.

 

[Nomad Willy]

Rick,
*** Thats true. I remember looking at an Isuzu that I liked for my Willard ( the engine was on the small side even for the Willard ). I was of course thinking of putting the smallish engine in and working it hard* ..* untill I noticed the best BSFC was at 1800rpm, well below where I was going to be running the engine. I also noticed that the best burn rate was frequently at the same speed as max toqure for most or many engines.
**** On the Willard Boat Owners Group we have been kicking around the stats and the record of a 57' George Beuhler desingned*Diesel Duck type passagemaker with a single*55hp Kabota. The boat has very low draft, about 30000lbs disp and beam of only 11'* ..* only 6" wider than my 30' Willard.*The boat went around the world and for a long segment of the journey ran at 50% ( or a little less ) loading. Obviously for range. The boat is named Idlewild and I belive it is on Yachtworld. FF, I would think*Idlewild has some things in common w your new boat. Idlewild is clearly ( in my opnion ) a look into the crystal ball. Some day, sooner or later the*cost of fuel will go up and stay there.

Eric Henning

Eric Henning*

 

[Allan]

I have my 65 foot trawler based in Singapore. The price of fuel here is $6.40 @ gallon. You guys in the states get it cheap.
Even at the price we pay it does not stop us from cruising all year round.
M/Y Monika holds 5000 Liters and this gets us close to 2000 miles range.
Its like smokers, if the price of cigarettes when up to $20 bucks a pack, people will still buy them.

The whole object of owning our boat is a lifestyle issue and I myself would pay anything to keep that lifestyle.
Freedom, achievement, adventure, satisifaction and pride in doing what you love.

Allan M/Y Monika

 

[2bucks]

NomadWilly says: "Ken, Ill bet Steve DeAntonio thinks the same as in the past and put that comment about 50% loading in there because of all the flak and stuborness he undoubtedly recieved from old trawler guys unwilling to accept his platform"

Stuborness? I'm looking around here trying to find some. Anybody see any? I don't see any stuborness. You see any stuborness?

))

Ken

 

[Marin]

nomadwilly wrote:

****Marin, ...With that upsidedown filter you probably get hot oil all over the place including your hands. Get a remote filter kit and mount it*on a bulkhead......*** Marin, that Northern Lights guy really needs to know about radial tires.

We already covered the upside-down filter issue earlier in this thread.* Punching holes in the bottom of the filter*(which is facing up on the stock oil filter mount of an FL120) before starting to pump out the engine's sump oil results in the oil filter being virually empty of oil by the time the sump oil is out, so there is no mess when the upside-down filter is unscrewed.* The holes release the vaccum and all the oil drains out into the engine.

I have no idea what your radial tire reference with regards to*my engineer friend at Northen Lights is about.* If it's an implication that he's behind the times, well let's see.....** Over the last thirty-plus years he*has been involved in everything from Lugger engine swaps in older boats like*Grand Banks, to*countless engine speccing and installations in commercial fishing, crabbing, and processing*boats,*to the engine and generator planning, speccing,*and installation design work for Paul Allen's current 400-plus foot yacht.

He also works with the*Northern Lights/Lugger base-engine suppliers in Japan, Germany, and the US to tailor their engines to Northern Lights' requirements.* I would say his knowledge and experience with marine propulsion*diesels and generators*far exceeds anyone on this forum with the possble exception of Rick B, and probably well exceeds even*the vaunted Steve D'Antonio.* So when he talks about oil requirements or any other aspect of marine diesel operation, he's not just spouting armchair theories based on heresay or being a boat owner for a few years.

If the tire reference had another meaning I'm afraid you'll have to clarify it for me.

Cheers from China,


-- Edited by Marin at 03:32, 2009-02-12

 

[FF]

Warm it up for 15-20min and then work it hard for 10 min .. run back into the slip and pump it out ( the oil ).

Better than not warming

BUT,

About 15% of the oil is the additive package which includes detergents.

The crud settles out of the oil and collects in pan and other slow drainibg areas.

It takes TIME , hours not min to re encapsulate the crud and get it into suspension , so it can be drained.

Observe how long it takes for the oil to get black, your way , then try a change after a 5 -10 hour long run , and see the difference.

Only works with OUT a bypass filer system (real , not toilet paper) tho.

 

[2bucks]

So help me understand this. The additives in the oil don't encapsulate and keep the contaminants in suspension? They only break them loose from the surface when the oil is flowing? How would that ever work on the bottom of an oil pan, especially in the corners where there is vitrually no agitation.

That seems counterintuitive to me. I've always thought that the way the detergent additives worked was to encapsulate the contaminant and keep it is suspension so they didn't build up on the walls or coagulate in the bottom of the pan. I remember the big sales pitch when detergent oils were first introduced, and my memory is that the advertising for detergent oils said it worked that way.

Ken

 

[sunchaser]

Of the many things to worry about on our toys, crud in our pans via organic osmosis is*not one. Just pump/drain out what your book says is capacity & you'll be fine. Not uncommon to have a remaining quart or so if you pump out through your properly installed oil drain pump fitting - which should be on the "bottom" of the pan.

According to Tony Athens at boatdiesel, engine failure due to lubrication issues are a very rare thing. This assumes you due the right maintenance and checks. I know a really lazy guy who never checks his gas engines oil level because the hatch is too heavy. But he does change the oil yearly. Never more than a quart down.

 

[Nomad Willy]

Hi Marin,

*** I hope you have time for this kind of chit-chat on the job over there in China. Your asumption about the inference to your friend ( NL )*is correct. Sometimes the amount of experence one has is not the bottom line. What they have learned along the way is. Iv'e seen many pilots with lots of air time both GA & UL but nearly all thier air time is in the pattern. Your friend dosn't sound like that kind of guy, so** .. I'll bite* .. next time you see him and have the time ask him what's wrong with*synthetic oil. Iv'e used a lot of synthetic oil ( mostly 2 strokes ) and read a lot about it ( mostly in motorsports magazines ) so I don't know all there is to know and I'm willing to learn.

Eric Henning*

 

[2bucks]

I think I hear Eric saying there is a difference between 20 years of experience and 1 years experience 20 times. I agree completely.

Ken

 

[RickB]

"So help me understand this. The additives in the oil don't encapsulate and keep the contaminants in suspension?"

They don't "encapsulate"* they are held in suspension. It is a colloidal suspension so it is very stable and not easily separated when cool. Nearly all the contaminants are carbon, that's why the oil is black. They will settle after a considerable length of time if the oil is not circulated*and is kept hot, but that's not exactly a common condition on recreational boats. The stuff won't settle out of cold oil in a boating season.

If the level of contaminants exceeds the capacity of the detergent or dispersant*additives to keep them in suspension, new particles will settle out. The way to avoid that is to change the oil before that happens. That is the*reasoning behind oil changes based on*running time.*It doesn't matter if it is smoking hot or not, just so long as it is warm enough to flow.

On ships we have lube oil test cabinets and test oil for viscosity, TBN, water, and insolubles (soot) ... this gives us an idea of how well the filters and centrifuges are working and how the additive package is holding up. We still send samples to a lab because*onboard testing does not provide any information about internal wear - unless*we find*large chunks of metal. *

-- Edited by RickB at 17:01, 2009-02-12

-- Edited by RickB at 17:02, 2009-02-12

 

[Marin]

nomadwilly wrote:

Hi Marin,

*** I hope you have time for this kind of chit-chat on the job over there in China......next time you see him and have the time ask him what's wrong with*synthetic oil.

Eric--

Between the occasional downtime on this project here, the ability to access the internet from our hotel, and the time difference across the Pacific*it's not too hard to find time to participate in the forum.

My friend does not say anything is wrong with synthetic oil.* I believe some or most of Northern Lights/Lugger's current engines use synthetic oil, or have the ability to use it.* In the conversations where oil types have come up, my friend is supportive of using synthetic oil in engines that are designed to take advantage of it.

Ten years ago,when we acquired our boat and asked him for advice regarding lube oil, he was less enthusiastic about synthetics as he felt more experience with these oils was needed before his company*jumped on board the bandwagon.* Many of their engines and generators end up in commercial vessels where very long term reliability is paramount and downtime due to having to make premature repairs is a Very Bad Thing.* So they, like many manufacturers of commercial-use engines, tend to take a fairly conservative approach to engine design and operation since the consequences of shortened service life or higher maintenance costs are pretty severe.

But in the ten years since he helped us acquire our boat, advances have been made in synthetics and there is much*more in-service evidence of their benefits, which he fully acknowledges.

What he HAS told me is that he does not feel synthetic oil should be used in old-generation engines like our Ford Lehman 120s.* The exception, in his opinion, is if the old engine has just undergone a total overhaul/rebuild during which*components, mainly seals,*that in their original composition could be susceptible to leakage or deterioration*with synthetics, have been replaced with components that are compatible with synthetics.* He says the newer synthetic oils have supposedly reduced this problem, at least to a degree, but his general recommendation is still*not to use synthetics in old-generation marine diesels.

In the case of our boat, which has its orignal engines which have never been overhauled, he recommended that we stick with the oil they have been run on since they were new, which is single-viscosity "dinosaur" oil.* His recommendation, and that of our diesel shop, too,*is Delo 400 30wt, which is readily available in the Puget Sound area.

So that's what we use.

When I get home I'll ask him specifically how he feels about synthetics today, and if he tells me anything that might be of interest to this forum I'll pass it on.

Cheers from China


-- Edited by Marin at 20:45, 2009-02-12

 

[FF]

How would that ever work on the bottom of an oil pan, especially in the corners where there is vitrually no agitation.

HEAT helps the oil to recapture the gropsh , as does time.

FF

 

[RickB]

"How would that ever work on the bottom of an oil pan, especially in the corners where there is vitrually no agitation."

The oil in a running engine is very much agitated. The pump suction generates a current drawing oil toward it, the oil slung off the crank and*spraying down from under the pistons coats every surface and flows downward to the pan from all sides and corners. This flow washes every surface. There are no little pools*with no circulation.

The idea that there might be probably comes from the old days when straight mineral oils deposited layers of oxidized crud in the low spots every time the engine stopped.*That happened because there were no detergents or dispersants to keep the crud suspended, it fell out almost instantly and hardened so that circulation could not mechanically remove it and there was nothing in the oil to chemically *hold it until an oil change.

 

[2bucks]

That's a pretty interesting bit of physics. The oil running down the sides flushes all the way to the bottom of the pan thru the couple inches minimum, of oil that is always sitting there. And the suction of the oil pump draws oil from the bottom so fast that it keeps the oil agitated but not aeriated.

That seems totally different than how my bilge pump works. You see it draws quite a bit of volume, but never scavages the bottom or sides of the bilge. It seems that the dirt/sand a foot away never gets drawn by the pump.

Now I'm also imagining that the spray washing down the sides from the crank and from the bottom of the pistons keeps the pan clean like a swimming pool stays clean from the rain pouring down and washing the sides. The pool circulation pump, like the oil pump is drawing a suction which pulls all the debris across the floor of the pool and into the filter? Is that how it works?

Ken

 

[RickB]

"Is that how it works?"

If the total volume of your swimming pool is circulated every minute or so, yeah, that's how it works.

If you think the insolubes in lube oil are the same as dirt and sand* in your bilge or leaves in your swimming pool then there is little hope of your understanding the subject.

If you are just trying to start an argument you should pick another thread.

-- Edited by RickB at 11:29, 2009-02-14

-- Edited by RickB at 11:30, 2009-02-14

 

[sunchaser]

This is really pretty simple. For some of you the answer to a perfect oil change is to remove your pan along with the filter each and every time you change your oil. While you're at it coat the now scoured out pan with marvel mystery oil before re-installing. For the other 99.999% of us just pump out or drain the warm oil as normal and refill with "modern" (last 45 years or more) detergent oil that is designed to emulsify or hold in supension*the normal crap and gunk.

 

[2bucks]

Your quote; "If the total volume of your swimming pool is circulated every minute or so, yeah, that's how it works."

Perhaps you can point me to a source that backs up your claim that the oil volume is circulated every minute. I've searched quite extensively and only find one source that gives a volume of oil pumped each minute.

This site: http://www.motorera.com/dictionary/OI.HTM says:
"Oil circulation The passing of oil throughout the engine. The engine oil circulation is maintained by a gear-type pump with an output of up to 35 liters per hour"

That seems to be a little over 1/2 liter per minute, a far cry from 3 gallons per minute.

If you're not just shooting from the hip, perhaps you can identify a source to back up your claim. Now remember we're talking about marine diesels here, not dual oil pump truck engines which use the engine oil to cool the injectors.

Ken

 

[RickB]

"Perhaps you can point me to a source that backs up your claim that the oil volume is circulated every minute."

Detroit Diesel Engine Division, General Motors Corporation
Form DE-MOM Three, Four, and Six-Cylinder Series 71, Two-Cycle Diesel Marine Propulsion Units

Section II Page 15 Figure 8:
Unit model 4073 Engine model 4-71 RC-48
Lubricating oil capacity: 17 qts
Lubricating oil flow at rated speed: 20 gallons per minute

Section II Page 21 Figure 11:
The 6-71 pumps 28 gpm with a sump capacity of 26 qts (depending on installation)

Satisfied?