A case for running engines off season (not?)

On the Cummins tech course I attended for Play d'eau's 6CTA 8.3 - M3 engines, I was specifically told it was bad practice to run them at the dockside 'just to warm them up' given the engines would not reach operating temperatue which would cause potential damage, mainly from internal condensation.

However, if I had to, e.g., for oil changes, to run them in gear (secure well!) at displacement cruising rpm., which I do. The engines then reach temperature.
 
Portofino said:
In no particular order there could be more reasons ?

Spreads fresh oil .
Mixes up a stagnant sump .
Turns any gears .
Exercises springs .
Recoats the inside of the pistons with oil .They dry up .
Oils the valve guides - they dry up too and suffer max wear @ dry starts after 6 months or so .
Removes any surface rust from the cylinders and valves with open exhaust valves = salt air access . [ loads of threads on knackered but infrequent used geny s ] .
Wets any drying oil seals . They shrink when dry = seep / leak .
Shifts any damp if there is any ? From sensitive sensors and other electrotwackerey .
Fuel injection pump gets a run out - seals ,gears springs + fresh static dose of diesel after shut down which will have a fresh dose of good additives to soak inside the expensive internal bits who,s dims are critical .
Injector tips get a run out - spring and any corrosion on the tip from open E valve blown way —- Er for now ! + fresh fuel left inside the canals / pipe work .
Click to expand...

But most of that list could be satisfied with 10 seconds of running the engine.

For me, logic suggests that it's cold starts that create wear, so even if you run it up to temperature you're not fixing the damage that's already been done!

But, I do wonder if a period of inactivity would result in a delay to getting the oil up to pressure. In my younger days, messing about with car engines, I was always told to crank the engine with the coil lead disconnected (or similar) until the oil pressure light went out before trying to fire the engine up. I wonder how long it takes to build oil pressure on my engines after a period of inactivity, I would hope before the engine fires up?

Anyhow, I won't be regularly starting my engines in the winter season (although the marina offer this as a service) and will add this to the list of things that I DON'T worry about (along with not having a starboard battery bank batter charger, not having seacocks in between my legs and impellors, not having bilge pump seacocks, leaving my battery charger on when I'm not on the boat, etc).
 
Portofino said:
As I said in my opening post it’s important to differentiate how you run them , MapishM still has not made thar clear , I do not idle mine ( never said or implied that ) I get them over 60 easily north of 1500 rpm when the turbos spool up .
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What I used to do with the the old lady's Caterpillars was running at idle for 20 mins or so (which brought the cooling liquid somewhere between 50 and 60 deg), and then increase rpm at 1000 to 1200 for another 5 to 10 mins max. That was good enough to reach normal operating temp.

Now, with the MANs, the cooling liquid temp was still under 50 deg after 20 mins at idle, so I refrained from accelerating.
After another 10 mins or so, with the temp around 50, I did used a bit of throttle, but never going N of 1500rpm - it just didn't seem right (I'm not saying it isn't, just reporting what I did).
Eventually, after 40+ mins, the temp was still nowhere near 60 deg and I gave up.
But this was my very first attempt with the MANs, since last winter the boat was sheltered and winterized for several months.
And I wasn't so happy with the result - hence this thread.

In the future, based also on what was discussed so far, I believe I will only turn them on whenever I'll have the opportunity to go out for a spin.
Btw, I'm lucky enough to be in a place where these opportunities are not so rare, even in the worst months of the year, so it's more a matter of defeating laziness than anything else... :rolleyes:
And the fact that it's better to run the things under load gives a sound motivation! :encouragement:
 
Piers said:
On the Cummins tech course I attended for Play d'eau's 6CTA 8.3 - M3 engines, I was specifically told it was bad practice to run them at the dockside 'just to warm them up' given the engines would not reach operating temperatue which would cause potential damage, mainly from internal condensation.

However, if I had to, e.g., for oil changes, to run them in gear (secure well!) at displacement cruising rpm., which I do. The engines then reach temperature.
Click to expand...
I had zero concerns to put the engines in gear while docked with the old lady, whose reactions were always extremely smooth and predictable.
Which also means somewhat delayed, but that's something easy to live with, once you get used to it (clue ships).
The trouble with these blxxdy P boats is that they jump ahead like scalded cats, when you put even just one engine in gear - let alone if you dare to touch also the throttle...!

That aside, thanks for your further confirmation ref. not to run engines just to warm them up.
Pretty much confirms the conclusion I already reached, as per last para of my previous post. :encouragement:
 
MapisM said:
What I used to do with the the old lady's Caterpillars was running at idle for 20 mins or so (which brought the cooling liquid somewhere between 50 and 60 deg), and then increase rpm at 1000 to 1200 for another 5 to 10 mins max. That was good enough to reach normal operating temp.

Now, with the MANs, the cooling liquid temp was still under 50 deg after 20 mins at idle, so I refrained from accelerating.
After another 10 mins or so, with the temp around 50, I did used a bit of throttle, but never going N of 1500rpm - it just didn't seem right (I'm not saying it isn't, just reporting what I did).
Eventually, after 40+ mins, the temp was still nowhere near 60 deg and I gave up.
Click to expand...

What's the operating temperature band for the oil P?

MapisM said:
But this was my very first attempt with the MANs, since last winter the boat was sheltered and winterized for several months.
And I wasn't so happy with the result - hence this thread.
Click to expand...

What was the result?

MapisM said:
In the future, based also on what was discussed so far, I believe I will only turn them on whenever I'll have the opportunity to go out for a spin.
Btw, I'm lucky enough to be in a place where these opportunities are not so rare, even in the worst months of the year, so it's more a matter of defeating laziness than anything else... :rolleyes:
And the fact that it's better to run the things under load gives a sound motivation! :encouragement:
Click to expand...

I think there's lots of good reasons for giving a boat a run over the winter so I'm all for that suggestion!
 
petem said:
But most of that list could be satisfied with 10 seconds of running the engine.

For me, logic suggests that it's cold starts that create wear, so even if you run it up to temperature you're not fixing the damage that's already been done!

But, I do wonder if a period of inactivity would result in a delay to getting the oil up to pressure. In my younger days, messing about with car engines, I was always told to crank the engine with the coil lead disconnected (or similar) until the oil pressure light went out before trying to fire the engine up. I wonder how long it takes to build oil pressure on my engines after a period of inactivity, I would hope before the engine fires up?

Anyhow, I won't be regularly starting my engines in the winter season (although the marina offer this as a service) and will add this to the list of things that I DON'T worry about (along with not having a starboard battery bank batter charger, not having seacocks in between my legs and impellors, not having bilge pump seacocks, leaving my battery charger on when I'm not on the boat, etc).
Click to expand...

Our MANs and I suspect the others ( big ones ) run the oil pump before firing .Theres an alarm you wait fit it to go off when it’s ready for the final turn of the key to fire .
I know with outdrive VP stuff my old KAD 300 ,you could not rev above 1500 out of say 3600 /3700 ish in N at the dock .
I can WOT mine in N at the dock and see the temps jacket and oil rise as said over a 20/30 min build up and still obey the
“ thow shalt not idle for greater than 5 min rule “ cast in stone in the MAN manual.

The only thing I can’t get is the EGT s north into the zone around 550 /580 degrees .Only prop load dosas this .
Idke they drop to 100 maybe a bit higher v quickly even pooling in the marina returning from a fast run out .
I can get them to around 300 around 2000 rpm in N at the dock .
But as said I assume I,am blasting out any excess agglomeration products ( N of 2000 rpm ) ie not them build up at idle rpm , the 5 min rule .
600 rpm gets no where near the correct cylinder pressures even with the best electrotwackerey for the optimal burn of the fuel hence the agglomerations.
I think that’s what MAN are on about re prolonged idle not a temp issue per se , but related I guess from cold if you don,t or can,t in the case of VP stiff rev em up at the dock .
Remember after a run out in the summer evethings stinking hot in the ER and MAN still play the 5 min rule card .

Which let’s face it I think we all fail dismally., entering a marina , fendering up ,manoeuvring for docking , getting the lines etc .

@Piers I don,t get the condensation point ( well not in the Med ) -just run that by me ps .
Cold metal and damp ? Explain the mechanism please
Where’s the damp ? Air or oil or both ? .
Engine surely gets warmer when runing , more so we’ll mine do at 2000 rpm with the turbos howling away .
 
MapisM said:
What I used to do with the the old lady's Caterpillars was running at idle for 20 mins or so (which brought the cooling liquid somewhere between 50 and 60 deg), and then increase rpm at 1000 to 1200 for another 5 to 10 mins max. That was good enough to reach normal operating temp.

Now, with the MANs, the cooling liquid temp was still under 50 deg after 20 mins at idle, so I refrained from accelerating.
After another 10 mins or so, with the temp around 50, I did used a bit of throttle, but never going N of 1500rpm - it just didn't seem right (I'm not saying it isn't, just reporting what I did).
Eventually, after 40+ mins, the temp was still nowhere near 60 deg and I gave up.
But this was my very first attempt with the MANs, since last winter the boat was sheltered and winterized for several months.
And I wasn't so happy with the result - hence this thread.

:
Click to expand...
N of 1500 rpm ish , when the turbos spool ( and the bearings get a good lub btw - what’s not to like ) then you will see a real rise in temps .
The 60 degree rule from the MAN manual is quite interesting as below 1500 ( turbo spool trigger rpm ) it takes ages out at sea and as you have discovered at the dock .
What I do out at sea from a cold start - is push it over D speed , you know the award bow wave inefficient fuel burn place .
The jacket temps rise in few mins then , I am off as soon as I see 60 water temp push the sticks fwd and up she comes , then switch to the load screen and as said set the rpms at 80 % load .
Never set cruise rpm with the log / speed - always load every time .

Having said all this re winter use out of the 5/6 dead months last year we did take a blast around the bay with two of those the Feb and March , We were on our own .
All cocks are closed and exercising them is part of the monthly boat check as well as running up every system / pump / switch inc the main engines and geny .
Geny is easy to load up just turn a lot of stuff on .

What are folks view s on impeller set ?
 
MapisM said:
LOL, he's NOT in the Med, in fact! :)
Click to expand...


Yeh I know so the cold iron is colder than Med iron so that would imply a greater propensity for condensation esp in N damp climates - thus a greater more usefulness of trying to drive out the damp from the oil and internal ( now dry less oil coated cos they not been run for weeks ) .
Caveat- if you can get them up to temps , not talking dock idling I get that .
 
Assassin said:
Mapis, the reason they do this is nothing to do with the engines themselves as the marinised engines are different, most MTU engines are commercial or industrial engines and their differences are more than subtle, to begin with the industrial versions will nearly all have swirl filters or a swirl filter for the air intake and as many operate in less than ideal conditions such as dusty environments the reason they don't recommend idling them for long periods is that they do not pass sufficient air for the swirl filters to work properly. Basically it means that the engines are drawing excessively dirt laden air straight into their air filters and the lack of swirl means they aren't removing the larger particles from this incoming air as they would if they were running within their working range.
Click to expand...

Nothing like this was mentioned when I went on the MTU engineering course.
 
MapisM said:
Haha, good point.
An alternative moral could be "if you want to run your engines regardless, do it in the morning!" :D
You made me curious, btw: do you flush the engines and possibly the seals with fresh water, when you know that you are not going to move the boat for some months?
Besides, remind me which shaft seals you've got, PSS?
Click to expand...

I don't have a way to flush the seals with fresh water.
I'm not sure it would help anyway - the water feed flushes the seal towards the sea so sea water would quickly replace the area behind the gland.
Not sure what you mean by SS.
Like most, I believe, our seals are made by Tides Marine.
 
Hurricane said:
Not sure you are right these days.
I was lead to believe that the MTU CR2000 M9x series offerings were designed specifically for marine use.
See this data sheet
https://www.transdiesel.com/app_docs/mtu 8v2000 and 10v2000m94.pdf
Click to expand...

Those 16 and 22 L blocks in the link are prime size for none marine use a well .
Sure the bolt on bits like the HE,s CAC ,s water pumps are “ special “ but surely the block , crank , pistons , valve gear etc are common to none marine units .I know MAN are indeed totally interchangeable.
If I was CEO or head of development i would make sure too to stay competitive .

How ever let’s just run with your idea those examples are low Hp variants , for continued everyday , every week use like in a ferry , tug or support vessel so the 6 months stud about not run scenarios ( just because it’s cold outside / winter ) are not or were not factored in .Thats why the manuals are silent on prolonged stop periods .They assume you use the thing all year esp low Hp continuous duty stuff .

Just to be clear as said earlier prolonging stop times are in my book different to total winterisation and storage regimes which the manuals explain , but who pulls the injectors and sprays fogging agents in etc etc .

That adds strength to the give em a run now and agian as opposed to simply pull the keys in Oct and never touch until April school of thought . So you can tell I,am not in that camp with my IC engined powered toys
Stress as long as you can get some decent heat into them .

Each to there own but nobody’s thus far put fwd any sensible reason for leaving them stud unused for the winter .
Sure a lot of fear about ( VP stuff maxing rpm in N @ 1500 accepted ) about inability to get them up to a unharmfull temp .The Q if I understand it correctly is about is it ok to leave marine liesure high Hp variants unused “ as is “ for up to 1/2 the time in a year .- just take the keys out and forget .

If you can run them ( to reasonable temps ) why not ?
 
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Portofino said:
Those 16 and 22 L blocks in the link are prime size for none marine use a well .
Sure the bolt on bits like the HE,s CAC ,s water pumps are “ special “ but surely the block , crank , pistons , valve gear etc are common to none marine units .I know MAN are indeed totally interchangeable.
If I was CEO or head of development i would make sure too to stay competitive .

How ever let’s just run with your idea those examples are low Hp variants , for continued everyday , every week use like in a ferry , tug or support vessel so the 6 months stud about not run scenarios ( just because it’s cold outside / winter ) are not or were not factored in .Thats why the manuals are silent on prolonged stop periods .They assume you use the thing all year esp low Hp continuous duty stuff .

Just to be clear as said earlier prolonging stop times are in my book different to total winterisation and storage regimes which the manuals explain , but who pulls the injectors and sprays fogging agents in etc etc .

That adds strength to the give em a run now and agian as opposed to simply pull the keys in Oct and never touch until April school of thought . So you can tell I,am not in that camp with my IC engined powered toys
Stress as long as you can get some decent heat into them .

Each to there own but nobody’s thus far put fwd any sensible reason for leaving them stud unused for the winter .
Sure a lot of fear about ( VP stuff maxing rpm in N @ 1500 accepted ) about inability to get them up to a unharmfull temp .The Q if I understand it correctly is about is it ok to leave marine liesure high Hp variants unused “ as is “ for up to 1/2 the time in a year .- just take the keys out and forget .

If you can run them ( to reasonable temps ) why not ?
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Every time you start an engine from cold you are adding wear to it. It makes no difference whether it ends up at normal temperature, the wear has already taken place. It's simple logic!
 
petem said:
Every time you start an engine from cold you are adding wear to it. It makes no difference whether it ends up at normal temperature, the wear has already taken place. It's simple logic!
Click to expand...

Not n disagreeing with the “ simple logic “ but if you simplify stuff back and back and so forth at every step you lose a nuance or two and end up far away from where you started .

I thought I covered that point ( cold st ) in my post #18
For ease here it is

Mike F point - sum of cold starts - well I,am adding 5/6 on .
Since retiring we are on the boat the marortiy of a month from May to the end of Sept , this year the longest stint was over 3 weeks and every day we used it ,
Are folks saying “ I,am not going out today because I,am conscious I’ve used up me annual cold start quota “ ?

So how far back do you take the “ simple logic “ ————- to not using at all ?? , to staying in bed because of the fear of a piece of airplane blue ice ( frozen shit ) hitting you when you walk across the road ? .
Simple logic says there’s zero chance of that if you stay in bed .

The benefits of regular runs ( upto temps ) far out weigh not doing so .
Specifically regarding the valve guides the most at risk parts imho of prolonged un run IC engines , it’s those parts that REALLY benefit from a fresh dose of oil additives .You oil additives are chemicals which get spent doing there job while coated over time .Nice to re spread em out as opposed to let them literally distil in the murky sum for months on end .
Oil needs a good mix up and spread out , recoat as much as you can , as frequently as you can and of course as hot as you can .
 
Are you all worrying too much about the theory of all this. I cant help thinking that compared to the number of cold starts a car has over a boat (I would think at least a multiplier of 100) it is all rather irrelevant. Most of my cars are terribly abused re servicing and starting etc by me and I have to say I seldom have any issues.

I am sure someone will now wade in telling me how different a boat engine is over a car or lorry............................ In advance and in modern speak my answer might be Really !
 
So let’s declare a score draw!

Some do some don’t. There is no evidence that either suffer huge problems either way other than hurricane sinking!

The engines rot long before they wear out in boats. I have just fresh water flushed mine ( did consider Evian!) as it stopsxanode corrosion and critters in the heat exchanger so no is starting my engines until April !
 
Hurricane said:
I don't have a way to flush the seals with fresh water.
I'm not sure it would help anyway - the water feed flushes the seal towards the sea so sea water would quickly replace the area behind the gland.
Not sure what you mean by SS.
Like most, I believe, our seals are made by Tides Marine.
Click to expand...
Actually, as I understood (straight from the horse's mouth, i.e. the chap in charge of technical support at Fluiten, the builder of my seals), it still makes sense to flush shaft seals with fresh water.
The logic is that salt water is heavier than fresh water, so after "filling" the through-hull section of the shaft behind the seal with fresh water, there will be very little (if any at all) sea water finding its way back upward, while the boat is sitting there unused.

Ref. PSS (not SS), it's just another type of shaft seals, made by PYI, a US Company. For some reason, I had in mind that Princess used their stuff...
 
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