Running Engines in Winter

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DougH

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Was recently out in Mallorca and got into conversation with some Professional Skippers and a couple of Engineers on the subject of running engines during the winter closed period.

It was a real amazing experience to hear so many diverse opinions on the subject.

Unfortunately all of them relied on the ' I was always told' principle and could not give an authorative answer.

I presume the oil plays a vital part in this argument so are there any Oil Experts who can give an opinion as to whether this practise is recommended?
 
DougH said:
Was recently out in Mallorca and got into conversation with some Professional Skippers and a couple of Engineers on the subject of running engines during the winter closed period.

It was a real amazing experience to hear so many diverse opinions on the subject.

Unfortunately all of them relied on the ' I was always told' principle and could not give an authorative answer.

I presume the oil plays a vital part in this argument so are there any Oil Experts who can give an opinion as to whether this practise is recommended?
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Ahhhhhhhhhhhhhhh!

Expecting to see lots of contradictory posts following.

Personally, for my one winter with working engines I did start them from time to time because it gave me reassurance. Whether it actually did the engines any harm I don't know. Probably far less than unknown marine engineers over the years that make various 'c**k-ups' now being uncovered and rectified at my expense.

I probably need to say that I have 100% confidence in Gingie of this forum that is the process of rebuilding them and uncovering past 'sins'.
 
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My opinion is to run them as often as you can, it will help to reduce corrosion on every part of the engine from turning the seacock open ad closed, which cleans the ballvalve of marine growth, to the brushes in the starter and alternator just by spinning them up keeps thing clean, certainly the raw water pump impeller suffers being bent over up against the cam.

The oil is pumped around the engine washing all parts internally and externally, ive seen many rocker shafts and associated parts rusty after being stood.

The downside after running is the condensation that forms all over the engine creating corrosion eternally, a spray with wd 40 or similar does no harm on the bare metal bits.

The downside is if you have winterised the coolers are full of sea water again.

After doing this have a check round for any leaks, at least if a problem is going to occur it will be now rather than when you want to start the season.
 
I was reading the Volvo engine manual the other day and, like Paul said, it tells you to run the engines up as often as possible in order to keep it lubricated. It actually says that this should be done at least once every couple of weeks....
 
Aigua said:
I was reading the Volvo engine manual the other day and, like Paul said, it tells you to run the engines up as often as possible in order to keep it lubricated. It actually says that this should be done at least once every couple of weeks....
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Hows the new toy going? funny thing I was only talking about your sc35 today, was at the yard here in the midlands.
 
Absolutely loving it thanks Paul, massive difference over the last one! Couple of minor bits that are in the process of being sorted, Pete @ BW is being really good and sorting stuff without a fuss.

Sorry to the OP for the Thread drift!
 
Aigua said:
I was reading the Volvo engine manual the other day and, like Paul said, it tells you to run the engines up as often as possible in order to keep it lubricated. It actually says that this should be done at least once every couple of weeks....
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I've always been advised, to only start an engine, when your actually going to use it, as the vast amount of damage will be done on start up, more so if it never gets warm. Not saying that this would be right for a year or two.

The proof of the pudding being, my fathers trucks that were only likely to go a hundred yards between shops, lasted about ten thousand miles, where as the truck I took to the middle east, did around 500,000 miles, totally abused and still perfect.
 
The consensus is to run the engines for several reasons, oil circulation is one issue, basically keep it lubricated, and to ensure the oil gets hot enough to boil off any moisture in it. Turbochargers and other items also get a change of oil which they like, but the downside is if you have winterised the boat.

Never just run an engine for a short time, ensure its at working temperature and it remains there for at least 30 minutes, its not compulsory to run the boat, but its best to if possible.
 
omega2 said:
Run a diesel off load and glaze up the barrels!! wonderful.
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I was wondering how long it would actually take to glaze an engine and I came across this article on running in diesel engines in trucks. I was wondering how this will apply to new or rebuilt marine engines?

As usual,wikipedia has a good description of glazing in diesel engines. Clearly, not something that one wants to do to marine engines that are likely to need to be removed in order to fix this problem. From this article:

"Once glazing or carbon build up has occurred, it can only be cured by stripping down the engine and re-boring the cylinder bores, machining new honing marks and stripping, cleaning and de-coking combustion chambers, fuel injector nozzles and valves. If detected in the early stages, running an engine at maximum load to raise the internal pressures and temperatures allows the piston rings to scrape glaze off the bores and allows carbon buildup to be burnt off. However, if glazing has progressed to the stage where the piston rings have seized into their grooves, this will not have any effect."

I take this as meaning running our engines for a short while may cause some glazing but as long as it isn't too often then it will sort itself out on the next proper run out.
 
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The bores will glaze very rapidly on a new motor.

I was involved in running up newly built motors in a test cell in a former life and if I get my way will be doing so again soon. Just got to prise the dosh out of the MD's pocket as engine rebuilding is a new venture for him.

The key is to avoid sharp temperature gradients and get them under load as soon as possible to avoid glazing.

Start up and slow idle for about 3 or 4 minutes, ensuring the pressures are stable.

Introduce a moderate load at 50% power for a couple of minutes then wind the brake down to around max torque rev band. Leave at this setting until temps stabilise.

Wind off the brake and conduct high idle test.

75% power and wind down the brake again. Wait for temps to stabilise.

Wind off the brake and reduce power to 50%. Wait for temps to stabilise.

Repeat for about 2 hours then you can wind it right up to get the readings you need to sign the engine off.

No glazed bores, reduced oil consumption and happy, well lubed piston rings.

Going too gently is not good at all.

Every manufacturer will have their own method, but this way worked well with all makes and models of motor with the exception of the Cummins 504 which needed gentler handling for some reason.

EDIT: I forgot to mention, it is important to recognise bore glaze as opposed to bore polish, both of which can be caused by light loading but one is a function of wear, the other a function of incorrect operation.
 
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Running diesel engines in Winter

Whether running a diesel engine in Winter or Summer in the UK makes no difference, the important thing is whenever it is run to run it to full working temperature and ideally above 50% load.

This running will kep the lubrication system properly primed and all faying surfaces well fed with luibricant. The cooling system will be well flushed, and any salt deposits washed out, and the water pump lobes will not have time to develop a 'set' against the cam.

But it is also important to keep the load much lower until after the initial warm up period has passed, when the revs and load should be kept lower to allow the initial oil circulation to establish and warm up.

When the engine starts the oil will be cold and at its most viscous (thickest). It is during this period that the faying surfaces will also be at their driest of oil, so getting this oil film established quickly is important, as is using the correct grade of oil.

The pressure on the gauge will be higher, because this is measuring the pressure just after the pump, but that is because its higher cold viscosity has increased its resistance to flow, and the volume flowing to the bearing surfaces and the narrow operating clearances is actually significantly less. This means any higher load should be avoided until it has commenced warming, and this means you are seeing a notable climb on the temperature gauge (indirect cooled engines) above 40oC.

With my engines (Volvo Penta TAMD60C) I start them well throttled, but immediately limit the revs at 1,000 RPM and reduce them to idle as soon as the injectors have all clicked in properly and the engine will run at idle without hunting - approx 20 - 30 seconds.

For most boats following the engines being started will be a period of slow running whilst the boat manoeuvres from the mooring and this is just what the engine wants to get warmed up gradually. Once this period has passed bringing the load up will clear any glazing or other gums from the period of start up, that otherwise prolonged low power running can create.

Leaving the engine shut down for a prolonged period leads to the bearing surfaces losing the vital coating of oil from the previous run, the critical difference in Winter during the colder ambient is that condensation can form directly onto the faying surfaces and corrosion could occur. Although in Winter the cold viscosity will be higher (oil thicker) and the warm up period will be longer, so this also emphasises using the correct SAE rating.

However, in the UK most quality diesel oils are good for 0oC and not many of us will be going out on colder days. SAE30 is the basic choice (from 0oC), and if you run a multigrade such as SAE15W40 or 15W50 you will be covered for most operating conditions.

Oil left coated on the surface from the last run is a similar to the Tomato Ketchup left on the walls of the glass sauce bottle after it has been shaken & poured. You put the bottle away with large qtys liberally coated on the walls, but next time you get the bottle out these have all run down to the bottom. Oil left on the faying surfaces does much the same thing.

Firms like Castrol have spent £ Millions developing oils such as 'Magnetec' which is intended to keep the oil literally stuck where it was left, ready for the next start.

One of the worst things at shut down is to give the engine a rev up, as so often seen by motorcyclists. All this does is squirt excess fuel into the cylinders, which does not get burnt, and instead dilutes the oil and washes the cylinders. If your engines have just been operating at high power when it comes time to shut down the oil will be at its hottest and thinnest, and the run down period of the surface layer will be less as will the qty of oil left behind. Therefore it is better to allow the engines a period of warm down, so the excess heat from the high power run can soak away, and the oil can cool to a better level. Again the slow drive back to the mooring helps greatly with this, as does keeping the engine room vent fan going to assist the engine cooling down after the coolant circulation has stopped.

So it is the prolonged stop period and subsequent start that is the most critical.

The choices therefore are either run the engine properly and regularly all year round, i.e. at least once or twice per month, or Winterise it. If you cannot get off the mooring then run the engine at as high a power as you can, e.g. one ahead and one astern, but the power with the boat still will be difficult to get much above 25%, but this should be enough to stop bore glazing, just make sure the engine reaches its full temperature (20 - 30 minutes running).

Another feature of prolonged periods not running is the affect of marine growth and crevice corrosion on water lubricated bearings, such as the Cutlass Bearing. Regular rotation of the shafts prevents any build up of marine growth, that can otherwise form a very hard and rough mineral deposit along gaps between the flutes of the cutlass bearing, and these if form they are very effective at rapidly wearing the cutlass bearing down.

Similarly if the stainless shaft is left unmoved for extended period crevice corrosion where the shaft bears against the rubber flutes can lead to severe pitting, and the sharp edges of these pits can also scrape the rubber cutlass material away.
 
In winter, I will only run the engine if I take the boat out for a spin or going somewhere. When I first got my boat I was told by Volvo agent never to run the engine without load at it's berth, as this can do more harm than good, in particurlar bore glazing.

I'm am no expert on this, and it is interesting reading all the posts here, especially superheat6k. So, rather than sit at your berth running the engine, why not go out for a spin and enjoy it.
 
Superheat6k and Tinkicker0 many many thanks, this was just the advice I was seeking.

It now gives me the excuse to go to Mallorca every month.
 
Just use the blimming thing...

My opinion is to run them as often as you can,
After doing this have a check round for any leaks, at least if a problem is going to occur it will be now rather than when you want to start the season.[/QUOTE]

In a nutshell. IMHO
 
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Engine´s winter - sleep ?

Hallo ,
my engine is allowed to have a very deep winter - sleep like lots of animals.
before going to sleep : changing oil and filter , runnig to warm up and a pice of cloth
coatet with oil into the exhaust and intake. Good night engine ! See you again in the spring time. I do so since 1979.
Greetings

Hermann
 
HermannLenz said:
Hallo ,
my engine is allowed to have a very deep winter - sleep like lots of animals.
before going to sleep : changing oil and filter , runnig to warm up and a pice of cloth
coatet with oil into the exhaust and intake. Good night engine ! See you again in the spring time. I do so since 1979.
Greetings

Hermann
Click to expand...

Beautifully put Hermann.

Happy boating.
 
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