Gardiennage - starting engines, definitive consensus?

markc

markc

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Hi

Reading through recent threads there were plenty of differing opinions on this subject, but having just signed a gardiennage contract I'm sort of seeking consensus one way or another on starting the engines during the winter.

Engines are MTU 770hp - recently factory rebuilt on the bench 30 hours ago (700 hours total)

Question is

do I leave them unstarted for maybe 4 months ?

OR

Have them started once a month, just for 2-3 minutes off-load at idle to circulate oil & fluids with no intention to get them up to temp.

I realise that the best option would be to have the engines run up to temp under load, but that's not an option in this scenario with the gardiennage company as I don't want them attempting anything whilst moored up.

Cheers
Mark
 
I think its better to leave them alone unless you are going to run them properly and warm them up completely. Lots of short start/stops just increases oil contamination and creates the most wear. Anything covered in oil now, will stay covered in oil too.
 
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I am going to disagree with the prior two posters. I feel it is important to turn over not only the engines but also the shafts. Shafts left sitting in the same position in the cutlass bearings are prone to crevice corrosion where the rubber flutes are in hard contact with the shaft, and the areas exposed to seawater can build up a hard scale. A brief spin once each month allows the oxygen rich water to get to the stainless steel shafts (the oxygen maintains the stainless surface), and the motion will wipe away any growth before it gets a hold. This does not have to be a long run, just a minute or so at idle (obviously the ropes have to be well secured especially with 700HP engines).

Oiled surfaces may not hold their oil indefinitely, think of oil like sauce in a ketchup bottle - when you put the bottle back in the cupboard there is ketchup all over the surface, but a few days later when you next get it out it has all run down. Over a longer period of time oil does the same.

There is also a condition known as brinnelling where heavy shafts left sat stationary on bearings for extended periods can cause the bearings to deform.

I start mine at least one a month all year around, and allow a run until the temperature gauge is at least showing some temperature rise (at least 5 minutes). Doing this say 4 or 5 times over the Winter is not going to be enough to cause any noticeable bore glazing, or excessive carbon build up on the turbo blades.
 
I think it's all rarther a bit academic in the diesel engine longevity bigger picture .
In the sence of 10,s of Thousend,s of hours .
Think about it ,let's assume one way or the other does actually extend a big rebuild from 10000 to say 14000 hrs
Are you gonna be the owner doing less than 100 hrs /year to feel that benefit ?

I don,t think a short run of 3-4 mins is of any benefit infact harmful because the cylinder temp to burn the diesel in the least damaging way has not been reached .

A lot of German ,engines and poss others have a slight delay on the ignition ,or turned around a squirt of the oil pump to negate what Superheat6 K infers about drying journals /bearings ,-so that's a none issue
Personally I like them run up , periodically , but on the dock we rev ours up ( no rpm restrictions ) to temp .

"To temp "being the important thing .

Shift condensation ,mix sedimenting oil ( assume you do a Easter change ) , move the belt ,move the alternator , turn both impellers , stop water "setting " , lub the turbo bearings ,etc , excercise valves and springs , reposition the crank + pistons + camshaft when stopped .
As said above a quick , nudge into F ,the. R to turn the shaft + stir the gearbox oil .

What's the advantage of doing nowt for 6 /12 or what ever --- btw ?
Somebody sell the idea to me ps
 
quote; "This does not have to be a long run, just a minute or so at idle (obviously the ropes have to be well secured especially with 700HP engines)."

I'm not sure my pontoon cleats would cope, I used to let my sail boat engine run under a little load like this from time to time, but haven't dared to try it with even just one of my C12s in gear... perhaps I'm being too timid?
 
Phildorset said:
quote; "This does not have to be a long run, just a minute or so at idle (obviously the ropes have to be well secured especially with 700HP engines)."

I'm not sure my pontoon cleats would cope, I used to let my sail boat engine run under a little load like this from time to time, but haven't dared to try it with even just one of my C12s in gear... perhaps I'm being too timid?
Click to expand...

If we all get together maybe we can drag a whole UK marina down to Ibiza and pay UK mooring fees.
 
I'm with superheat. I'm not bothered about engines but like to spin the shafts once a month. I wouldn't trust a guardiennage service to do that though with monster diesels and coarse propellers. I just flick them into gear a couple of times, with just one prop revolution or for each in-gear stint. I also do this with freshwater raw water hosepipe cooling to the engines- qv other thread.
 
I had a chat with the MAN engineer who serviced my engines this year about this subject and he unequivocally said dont start the engines unless you intend to put them under load and warm them up to full operating temps. FWIW I have instructed my guardiennage provider not to start my engines regularly as they wanted to do but I know a skipper who I trust and I encourage him to take my boat out to sea whenever the opportunity arises so that the engines and props get a good work out. Again FWIW I have informed my insurance company about this
 
jfm said:
I'm with superheat. I'm not bothered about engines but like to spin the shafts once a month. I wouldn't trust a guardiennage service to do that though with monster diesels and coarse propellers. I just flick them into gear a couple of times, with just one prop revolution or for each in-gear stint. I also do this with freshwater raw water hosepipe cooling to the engines- qv other thread.
Click to expand...

I'm liking the idea of adding a little plumbing to allow freshwater flushing before longer periods of no use - have I missed a link to the mentioned previous thread on this? My raw water hoses are pretty fat - are there fittings around to enable me to add in a flushing point?
 
Phildorset said:
I'm liking the idea of adding a little plumbing to allow freshwater flushing before longer periods of no use - have I missed a link to the mentioned previous thread on this? My raw water hoses are pretty fat - are there fittings around to enable me to add in a flushing point?
Click to expand...

Yup I'm interested in that too
 
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