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I'm a little suspicious of the 75/75 "requirement" myself. I understand the need to avoid excessive idling and unloaded operation (like running an engine 2-3 hours to charge batteries), but haven't seen any hard evidence of long term 40-50% power shortening engine life.

Go to the John Deere marine engine web site, for example, and note that they show the identical engine with three different power outputs depending on the duty - and the engine with the lowest power rating has the longest life. For example, the 6068TFM is rated at 225 HP for "up to 800 hrs/year", but 154 HP for "over 3000 hrs/year".

Nowhere do I see any "minimum load" requirement.

Like Marin, I have an aviation side. Same discussions there - "run them at 75% or harder all the time - they love it." But those folks seemed to keep complaining about how they were always replacing cylinders once or twice between major overhauls.

Perhaps Northen Lights means "You ***can*** run them as though you hate 'em" - not "You ***must***".
 
Steve,
Indeed it was. I wonder how many of us read PMM ? Last year I went nuts buying and reading back issues. I even made lists of all the articles, categorizing all the subjects filling my head with all kinds of stuff. Couldn't get enough. This year read them all but don't find them a priority at all. There was another large yacht ( old and wood ) on the west coast, also powered by a Gardner that only had 2 hp per ton. I'm supprised Krogens run around 7 hp per ton. I saw Radiant Star for sale last fall for 825K. I could buy my favorite boat ( Nordhavn 46 ) and some real nice real estate here in SE Alaska for that.

Eric Henning
30'Willard
Thorne Bay AK
 
Hi Marin,
Yeah, I wish we had CHTs on our boats too. I flew ultralights for years and I remember my eyes were glued to the CHT on climb out. Some engines ran 425 degrees all day long and others would sesize up every time we got to 401 degrees. Engine coolant tempeture on a diesel boat is a very bad thing to use to gauge engine load or when when an engine is ready for heavy loading. Most boats will indicate over 95% heat soaked at a 25% load. The coolant is forced to get hot fast by keeping the coolant mostly out of the heat exchanger at low loads. At 25% load the pistons, rings and valves are very cool ( relatively speaking ). Lube oil temp is a better gauge but boat engines vary too much in design to through numbers out to the general public. On some boats the lube oil cooler gets the sea water first. Here in Alaska that thats almost freezing much of the time and if this oil cooler was extra large and the engine also had a large capacity oil pan the oil would stay quite cool even at heavy loads... and the opposite is also true. The 75/75 rule won't be really effective unless we can define exactly what 75% load is. I think the fuel burn method is good but how many boaters know thier burn rate at WOT? There is a lot of guys out there that don't even know thier WOT rpm. Ther'e not even proped right much less loaded right.

Eric Henning
30'Willard
Thorne Bay AK
 
I don't subscribe to PMM but Carey has given me his back issues to read. I have found some of the articles on VHF radio, navigation, etc. interesting and educational. The problem I have with the magazine (and this DOES tie into the topic of this thread) is that it is aimed almost exclusively at the top of the boating food chain. Big boats, expensive gear, etc. Folks who don't have to paw through their wallet to see if they can afford the fuel for next weekend's cruise, or who have to make do with their back-straining manual dinghy lift system because the price of a new Seawise Davit isn't in the cards right now. It's aimed at folks who can ask the question, "should I get the Fleming or the Nordhavn?" and then when they've made up their minds actually go out and buy one of them.

Now I'm well aware that magazine subscriptions don't begin to cover the cost of publishing a magazine, advertising does. And other than boat brokers, there are no companies out there pushing 30 year old boats and motors. And advertisers aren't going to cough up advertising rates unless they're confident that potential customers for their stuff are going to be reading the magazine. So it's a vicious circle-- the magazine needs to attract the kind of people who are inclined to buy the stuff their advertisers are selling, and their advertisers are selling new and expensive stuff. So gradually the anchoring technique articles get pushed aside in favor of a review of an Aleutian 70.

Some people--- maybe a lot of people--- like reading reviews about boats or equipment they can never afford to obtain. But I think a lot of people would like to read about stuff that relates to them. I'm not interested in the latest 900 kabillion horsepower, V-12*engine from MAN, but I would be interested in reading about some long-time boater's experience with the Lehman 120 in his boat and what he found to be helpful in prolonging its life. But that sort of subject matter won't attract advertisers (except maybe American Diesel) so it won't pay for the magazine.

The boats and engines Steve D'Antonio writes about have zero relevance to the boating world my wife and I live in-- a 34-year old "beater" GB with a pair of low-tech, low-rpm, low-power thumpers that have been out of production for almost three decades. So the engine management rules and suggestions that Steve preaches have little or no meaning for boaters like me.

I'm not so interested in hearing that I should be running my engine at 75/75.* What I do want to hear about is how can I minimize my fuel burn while ensuring a long life for my*1950s-technology*diesels.* I know there are ways to do this.* I know what they are for an even older-technology*Pratt & Whitney R-985 Wasp Jr., but we don't have those engines in our boat so the knowledge does me little good on the water
smile.gif


I think this is why forums for specific brands like GB, Hatteras, etc. are so popular and well-used. They take the place of that impossible-to-publish magazine that's aimed at the old-boat boater. Ideally, this forum will serve the same role.
 
Marin makes a good point. The particular boat that I won right now caused me some problem come oil change time. It has a fancy schmancy Oile X-changer system and I was really excited to use it the first time. So I got down to my boat and fired up the engine to warm up the oil. I ran it in gear for about 30 minutes with the coolant temp reading in excess of 160 degrees....perfect. Well I went to the X-changer pump and it started cavitating right away. I thought something was wrong. On further inspection, I pulled the dipstick out and it was not even warm. It was room temperature at best. So I said....alright....I fired it up and ran it out to Redfish and back(about 45 minutes under full load). I run 2900RPMs on a 3100RPM engine(3300 for 5 minutes). I get back and while it will pump the oil, it is STILL not hot to the touch.....it is warm but not hot at all. Anyway, that is where I am at now. I dunno if the oil cooler is too big or what. I take great caution in powering up now. I do it in stages if the engine is just getting warmed up. Makes ya wonder.
 
I dropped my subscription to PMM years ago. When they started building a picnic boat (probably to get a tax write-off for Palatore's new local toy) I decided they had totally lost their focus.

JB, there's something wrong for sure with your engine, running that cold. Did you do that recently when the bay water was cold? My first thought is that the thermostat is either missing or malfunctioning.
 
Interesting question as to whether there's anything to regulate the oil temperature. On an aircraft engine, there is a valve called a "Vern-a-therm" that only forces oil through the cooler when it hits 180 degrees or so. But in looking at the pictures of my T6.354's, the oil goes through the filter and raw water cooler with no obvious way for it not to do so.

So I think you can end up with cool oil even with the coolant temperature nice and toasty at the thermostat opening temperature.
 
Something is not right if your oil does not get hot. If my engine gets between 150 and 160 when warming up to change oil, it will burn my fingers right now. Even after all the oil is pumped out, and I go to remove the filter, it's too hot to handle without gloves.
 
I'll check it again next time I have it out.....
 
When we change oil in our Lehman 120s we run the engines in gear (one at a time) for about 20 minutes. The way I tell if the oil is hot enough to pump out easily but not too hot to handle is the temperature by feel of the oil filter. When it's "hot," but not too hot to hold my hand on, I know that the lube oil will flow easily.* But 15-20 minutes at about 1000 rpm in gear is all it takes to get the oil plenty warm.

-- Edited by Marin at 11:48, 2007-11-28
 
I also have nearly the same issues with PMM. I don't like the fact that small boats aren't represented well. Boats like the 25' Albin. There are only two ways to take giant steps toward reducing our fuel burn problem and they are 1. Go to a full displacement hull 2. Get a smaller boat. I'm about through with the power loading issue. I did some research and found a couple of paragraphs in a magazine article ( i'm scared to say which one ) that should be of interest to those of us that have not posted on this issue of power loading but are interested. A few years ago at a Trawler Port Forum Dick Gee ( Vice President of Engineering ) and a man named McElory ( Sales Director ) of Alaska Diesel Electric/Lugger/Northern Lights made this statement. " In general use the company recomends operating propulsion engines at a load factor of 50 to 70 percent of it's maximum power. A manufacturer's fuel consumption curve is needed to identify load factor. Devide the amount of fuel being used by the maximum possible consumption and you have the factor. On an engine that turns at a maximum of 2200-2400 rpm, the ideal operating range is going to fall in the general area of 1800 to 2000 rpm." Note the wide range ( 50 to 70 % ) and the expression " general area". I think Chris Foster and Marin have stated or implied that the 75/75 rule should't be taken literally and I agree. My own new rule is 50/80

Eric Henning
30'Willard
Thorne Bay AK
 
FWIW Dick Gee is the friend who advised me on the best way to run our Lehmans.
 
Finally found the article that I read a while back on lower power operation. It's on boatdiesel.com (pay membership) and also free at

http://sbmar.com/Articles.cfm

Scroll down to "Low Speed Running and Break-In Of Marine Diesels".

Money quote:
As for life expectancy on a typical modern high speed diesel engine (probably an old one too), when run at 10-50 % of its rated hp, you'll get longer life (substantially in many cases) when measured in engine hours, everything else being equal.

Read the whole thing if you get a chance.
 
Another thing that you might wanna think about is the power curve is not necessarily linear. My engine is rated at 190hp@3100rpm and 240hp@3300......50hp in just 200 rpm. So don't necessarily relate power loading with RPMs....of course there is a turbocharger involved here.
 
Marin wrote:

FWIW Dick Gee is the friend who advised me on the best way to run our Lehmans.
Click to expand...
Marin:

So, what is the best way to run your Lehmans?* I could use some advice.

- Darrell

*
 
With the boat we have and the props currently on the boat, we run at 1,600 - 1,700 rpm (the tachs aren't all that accurate). That gives us a tad over 8 knots at 6 gallons per hour (total both engines). Coolant temp is about 180, EGT is 600 degrees f.
 
"When we change oil in our Lehman 120s we run the engines in gear (one at a time) for about 20 minutes. When we change oil in our Lehman 120s we run the engines in gear (one at a time) for about 20 minutes. "

This is pretty much a waste of time and oil.

Modern oil has addative packages thart include detergents.

*These need time and heat to disolve the sludge and gunk that is fine enough to keep passsing thru the oil filter.*

To help the service life of the engine* a good days run , at load is required to disolve all the crap out of the engine , and get it suspended in the oil.*

That's the time to change the oil (even though it sucks working in a hot engine room) and actually help the engines service life.

*Prefill the filter and restart after the change to get the new oil in all the passages , run for a min to look for leaks. The restart while hot is so the oil hasent drained from the bearing surfaces , so no cold dry start wear.


This is also GREAT to do , just before pickeling the engine for a winter .

FF*

FF
 
Sounds a little extreme to me, after running your boat in 90 plus degree weather all day it would be hotter than he** in the engine room.
 
In addition to the good point made by Troy, the last thing we want to do after getting back from a cruise at the end of a day is screw around getting the oil evacuation pump out, opening up hatches, punching holes in filters, and generally getting all hot, sweaty, and dirty for an hour or two just for the sake of a few specks of sludge. Plus we don't use "modern" oil. We use the old standby Delo 400 and since we change it every 100 hours it's not in there long enough to get very dirty
smile.gif


I have a Land Rover that I bought new in 1973 (same year our boat was made). I change the oil in it (and all our other vehicles) every 3000 miles. I don't run it at all before changing oil, I just change it cold. At 120,000 miles we had to replace a valve that was starting to burn, so we went ahead and replaced all the bearings and seals in the engine since we had it apart anyway. The engine build-up specialist who did the rebuild for me was amazed when he pulled the crank and camshaft out of the engine--- he said all the bearings and bushings and wear surfaces looked as though they'd hardly been run at all, and the inside of the engine was clean as a whistle. That's just from being religious about changing the oil and filter.

-- Edited by Marin at 15:00, 2007-11-29
 
FF wrote:
This is pretty much a waste of time and oil.

Modern oil has addative packages thart include detergents.

These need time and heat to disolve the sludge and gunk that is fine enough to keep passsing thru the oil filter.

To help the service life of the engine a good days run , at load is required to disolve all the crap out of the engine , and get it suspended in the oil. (endsnip)

Well, I think this is the new dumbest thing I've read lately. If running at load will disolve all the crap out of the engine, then all the crap will be in the oil and warming it will work just fine.
Trying to change oil in a boat engine at running temps would be dangerous, uncomfortable, and totally un-called for.

I think I'll keep doing it my way.
 
You Failed to notice the requirement for modern detergent oils to function,HEAT AND TIME .

A modern diesel is far too efficent to do very much heating at idle in a slip , and the folks that own the marina get whizzed when you run it in gear , washing bottom material aft.

When warm it takes hours+ to pick all the gunk that has settled and get it into suspension.

It is A delusion that you can forgo the requirements cause it SUCKS to climb down into the Hell Hole , when completing a long trip , and youre done with the boat ,because Dello is "old oil".
ALL modern oils are CE or CF or better as modern as required for todays engines .

How you treat your vessel is your concern , but for the folks that wish the LONGEST service life from the powerplant , HOT change & warm restart is STILL the best procedure.

FF
 
I still think that is nothing more than a bunch of BS, besides far superior navy vessels should be immune to such issues.
 
FF, I think it is safe to say you are a theoretical boater!!!
 
Nah ,, We did our 5000miles in 4 months so far this year ,I'm a LAZY boater.

For me its far easier to follow Da Book (as I had to do for 25,000 hours of airline bus driving) than do forced maint.

The chance of ever having an oil related problem is lowest IF one follows the "best" procedure.

I love being inventive and doing creative prpblem solving , an engine change , or just a set of bearings is simply WORK (a 4 letter word to this retiree) so I take the time to find out the "Right way" and do it.

Not very creative , but sure saves that 4 letter word!

FF
 
I asked a good friend of mine who has been the head of the
engineering department of one of the industry's most respected diesel
manufacturers for several decades about FF's recommended oil change
procedure. His response was to laugh and say that if I wanted to change
our oil when it's scalding hot after a cruise it won't hurt anything.
But changing it when it has been just warmed up enough to flow OR is
still COLD won't hurt anything either. Regardless of which method you
use, it will not make one iota of difference to the life of the engine.

What DOES makes a difference to the life of an engine, he said, is how
often the oil and filters are changed, how the engine is operated, and
how it is maintained.

He said that any differences between changing the oil when hot, when
warm, or when cold will be so insignificant that an engine will fail or
wear out for some other reason LONG before the oil change method has any
positive or negative effect on the engine's longevity.

So if you believe changing the oil when it's at its max temperature is
the right thing to do, no problem. If you believe changing your oil when
it's been warmed up by running at fast idle or in gear at the dock so it
will flow through the extraction system you use (dipstick tube, etc.),
no problem. And if your engine is mounted in such a way that you can use
gravity to get the old oil out as you do from a car's engine, no
problem. No matter what method you elect to use, you won't be affecting
the service life of the engine.

I believe him because in 40 years of paying attention I have NEVER seen
any professional mechanic--- automotive, aviation, or marine--- run an
engine up to full temperature and keep it there for a period of time
before changing oil. At best, they've run an engine long enough to get
the oil warm so it will flow out of the engine faster and more
completely. Or they've changed the oil cold. I'm including engine types
that range from old technology 1950s car engines to brand new BMWs, to
Peterbilt and Kenworth tractors, to Ford Lehman 120s, to brand new Volvo
marine diesels, to 1940s radial aircraft engines, to the GE90s on a 777.
 
Marin,
For a change I agree with everything you said ( that I can Remember ). But what is a straight and regular guy like you doing punching holes in oil filters? Sounds like strange and irregular behavior for a straight and regular guy like you. Got my curiosity up there Marin, way up there, two thumbs up. Are your filters remote and high so you can opke a hole and let all the oil drain into the crankcase? Do you drain the bottom of the filter to see what interesting stuff comes out? I hope you post a confession soon as my imaginations headed for la la land.
Why are you using old fashioned oil? More strange behavior. Whats old fashioned about Delo 400?Even I use Delo 400. I think Delo 400 will be around as long as there is Dinosaurs to make it out of. Ok i'm old. So enlighten me...what is a modern oil. One would need to know that to know what " old fashioned oil is.

Eric Henning
30'Willard
Thorne Bay AK
 
Eric---

The spin-on oil filter on a Lehman 120 is mounted upside down so it will clear the engine stringer underneath it. The following references to top and bottom apply to this upside-down mounting. The first time I serviced our engines I unscrewed the filter (knowing what would happen) and a quart or so of dirty oil poured out the bottom of the filter and of course the rags I had wound around it were not enough to catch it all. Big Mess ensued, including getting oil on the engine mount beside the filter which is bad for the mount.

Then someone told me the trick of punching a hole in the top of the filter after you run the engine to warm up the oil. During the time it takes to pull the oil out of the sump with the dipstick pump, the oil in the filter will drain into the sump because the air hole punched in the top defeats the anti-drainback valve. So after the oil is pumped out of the engine, I wrap a rag around the bottom of the oil filter and take it off. There is hardly any oil left in the filter at that point, so no mess.

FF talked about "modern" oils, so I didn't know if he meant newer multi-vis oil, synthetic oil, etc. Delo 400-30 has been around (apparently) since the Spanish Inquisition. I have no idea if it conforms to the particular characteristics of "modern" oils FF was referring to, but I figured if anything didn't it would be Delo 400-30.
 
Old oil is single viscosity dino oil. Modern oil is multi-viscosity oil and the synthetic and synthetic blend oil. Modern engines are designed and built using materials and clearances which work best with the newer oils. My daily driver requires full synthetic multi-vis oil, or at least that's what the manufacturer says. My lehman was designed and built using 1950 (1940?) technology and material. It doesn't need or expect synthetic multi-vis oil. Therefore it gets the old style oil when available.

What we haven't discussed yet, is the reformulation taking place in oil which has fewer of the old style additives in it. I forget the exact additive which is being phased out, but the old car industry is starting to perk up and take interest. I suppose I'll have to start paying attention and buy a few cases for my old BMW (1957) This is particularly aimed at gasoline engines but it may involve diesels as well. The thrust of the debate is that while the oil is the same brand and viscosity, the API classifications are changing and not meeting the old classifications that the engines were originally designed to run with.

Ken Buck
 
2Bucks

There are millions of people buying premium gasoline when thier engine never knocks on regular.There are millions of people useing synthetic and synthetic blend oils that need it like a platinum plated valve cover. Viscosity improvers only effect the oil's vis only very slightly. 999% of the time straight 30W oil will give better performance ( because there isn't something in the oil that adds no luberacation ) than all the high tec oils. The only reason to use high tec oils is when the tempetures of the oil reached during operation of a machine exceed the abilities of regular high quality oil such as Delo 30W. Your train of thought is that if we have something new all the " old " things don't work anymore. They work just exactly as good as ever before except when they are asked to do something new like cool and lubericate a turbocharger. Then you do need to see your engine specifications. Most all naturally asperatied diesel marine engines should use 30W.

Eric Henning
30'Willard
Thorne Bay AK
 
Hmmmm....... my modern car doesn't knock on regular because the knock sensor on the engine retards the timing so it won't. The performance suffers when that happens. I've tried both grades of gasoline and the 0-60 is different. I'm willing to take the manufacturers word for it when they specify a particular oil and fuel for that car. I'm not willing to bet the price of a new engine that "oil is oil" and any old type will work. They say to use 5w-20 so I believe that 30w doesn't flow into the closer tolerances of the new engines and provide proper lubrication.

snip "Your train of thought is that if we have something new all the " old " things don't work anymore." endsnip I'm not sure how you got that impression from my post. I think that the new things are designed with the new oils in mind. The old things, my Lehman and my 1957 car were designed with the old oil technology in mind. I think I stated that I intended to stay with that technology oil by buying some to keep on hand as the new formulations have changed and did not have the same additives.

Sorry if I left the wrong impression before.

Ken Buck
 
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