Hauled out, engine run regime?

No need for antifreeze in NZ The fresh water system will have coolant in it. There is really no need to do anything and certainly no need to run the engine unless you do work on it and want to check before the launch. change oil and filters when in the water so that you can run it first to get it warm which makes the oil easier to get out.
 
If it is going to be cold (below freezing), my advice would be to inhibit the raw water system. Flush through with a (non-toxic) antifreeze mix, then cap off the exhaust and drain the waterlock (if possible). Check the coolant in the fresh water system has enough protection for the temperatures expected - it's always colder in an engine bay on the hard. If it will be seriously cold and power is available, a small tube heater in the engine bay does wonders for the longevity and protection of the engine.
General advice when laying up for this period of time is to clean the engine and engine bay, slacken the drive belts and remove the sea water impeller. (I also like to disconect the engine harness so there is no possibility of an accidental start if you forget to refit the impeller!) If the impeller has no damage, I put it in a bag with some french chalk/talc and keep it as an emergency spare.
Some like to do a service before a layup, my personal preference is to do it before the launch, I can appreciate the merits of both. There is something satisfying about putting an engine 'to bed' with fresh oil in her - but I am an engineer and mechanically sympathetic! 😂
 
When the boat comes out I like to run fresh water through the raw water system to flush the exhaust then finish it off with an antifreeze mix. Running the engine further loses this mix.Hence, I would avoid. But I would put the batteries on charge at regular intervals to top up against any parasitic discharge
Edit
Clashed with #4 all of which makes perfect sense. I do change the filters & run the engine after to heat the oil to change it. It is so much better at the start of the season to hear the engine start on the first push of the button
 
The boat is in Christchurch New Zealand where the air temperature does not fall below freezing (currently 11 degrees daytime 1 degree nightime) so no need to put antifreeze in the raw water system (never really is even in UK0. The engine raw water system will already have coolant that includes antifreeze.

The boat will be out of the water for just 2 months which is no different from not using it in the water for a similar period. The OP will need to check that raw water flows when put back in the water - but that is not what he asked about.
 
Good to know there is no need for temperature protection.

There are differences with a boat on the hard vs being in the water for 2 months - maybe not enough for some to be concerned about, but enough for me. The purpose of inhibiting with a/f in the raw water system means the engine doesn't need to be run at all any further, and it adds corrosion protection (useful for those that have cast exhaust elbows).

Personally, I wouldn't advise running the engine frequently when the boat is on the hard, and some yards (many in the UK) prohibit it due to concerns that the vibrations could loosen the supports.
 
When I leave my boat ashore it is for six months, unattended. I carry out similar pre-layup actions as others have described but it is then left entirely. During covid it went three years without running but started in about 10 seconds of turning over.

There is quite a lot of evidence that running occasionally for short periods is particularly poor for diesel engine life, although less so since sulfur levels in fuel have reduced.
 
No need for running the engine.
A friend had his boat ashore 20 months without running the engines.
 
One anecdotal reason why it 'might' be peace of mind to inhibit an engine on the hard.
Many moons ago, the company I worked for had a repower project on a very nice Hallberg-Rassy. The reason: when hauling the boat, the yard lifted the stern too high and the sea water in the exhaust system backfilled the engine. The boat was out the water for 4 months over winter, by the time the owner found the problem the engine was seized solid and internally a mess. Due to lead times, the owner lost almost all the season by the time the project was complete.
On the plus side, the owner really appreciated his shiny new Volvo Penta, especially as the insurance covered it all!
 
Moodysailor said:
Good to know there is no need for temperature protection.

There are differences with a boat on the hard vs being in the water for 2 months - maybe not enough for some to be concerned about, but enough for me. The purpose of inhibiting with a/f in the raw water system means the engine doesn't need to be run at all any further, and it adds corrosion protection (useful for those that have cast exhaust elbows).
Click to expand...
Can you explain how running antifreeze through the engine helps the exhaust elbow? Really would not want any water left there for the reason you explain later. The water drains into the waterlock, so would prevent that from freezing in extremely low temperatures. If that were likely i would be much happier draining the raw water system completely and emptying the waterlock.
 
vyv_cox said:
When I leave my boat ashore it is for six months, unattended. I carry out similar pre-layup actions as others have described but it is then left entirely. During covid it went three years without running but started in about 10 seconds of turning over.

There is quite a lot of evidence that running occasionally for short periods is particularly poor for diesel engine life, although less so since sulfur levels in fuel have reduced.
Click to expand...
I left my Nanni 14 for 8 years drained of raw water and emptied the fuel tank. Changed the oil and filter, hooked up a water supply added fresh fuel and it started instantly.
 
Tranona said:
Can you explain how running antifreeze through the engine helps the exhaust elbow? Really would not want any water left there for the reason you explain later. The water drains into the waterlock, so would prevent that from freezing in extremely low temperatures. If that were likely i would be much happier draining the raw water system completely and emptying the waterlock.
Click to expand...
Hi, sure.

On small engines with cast iron exhaust elbows, as you know the water is injected into the elbow for cooling prior to mixing. Sea water and diesel exhaust fumes forms a mild caustic mix that accelerates corrosion.
As anti-freeze contains corrosion inhibitors, running this through the engine helps to coat the elbow and slow down the process.

In addition, there are often bigger temperature swings in the the engine rooms on the hard as opposed to when in the sea. The ocean acts as a heat-sink and stabilises the temperature swings. Without the sea surrounding the boat, the temperatures can vary a surprising amount and this leads to condensation forming on the metal parts. Add in the relative humidity being higher in winter, if the exhaust isn't capped off and the valve train is open even slightly, the exhaust mixing elbow on a cold boat is not a nice place to be with cold, damp air swirling around.

I have pulled apart engines and found traces of water damage on main bearings which has been attributed to condensation droplets in the engine. Running the engine for short periods does not generate enough heat to evaporate the condensation, it will actually contribute worse as a small amount of heat is generated and then the engine is shut down which allows more condensation to form due to the temperature differences. It will do the same in the exhaust. This is one reason why the statement from a previous post is correct that it is actually worse to run an engine for short periods.
 
When winterizing (Denmark, so gets a bit colder than NZ) I check/change antifreeze in the engine water jacket. Even if not freezing cold, the antifreeze contain inhibitors, as mentioned, that protect internal engine components from rust and corrosion.

Usual maintenance is done to oil/filters, protective spray onto engines and moving parts, impellers when required.

Any coolant drained from the engines is kept and used for flushing the sea water side, by pouring 10 liters into each seawater strainer at idle.

Batteries are laden fully and kept in storage mode by Victron chargers.

Domestic water system and holding tanks are emptied.

After 5-6 months on the hard during winter, it always starts at first turn of the key, no issues at all.

FYI: Toyota Landcruiser based Nanni diesels on shafts.
 
Moodysailor said:
Hi, sure.

On small engines with cast iron exhaust elbows, as you know the water is injected into the elbow for cooling prior to mixing. Sea water and diesel exhaust fumes forms a mild caustic mix that accelerates corrosion.
As anti-freeze contains corrosion inhibitors, running this through the engine helps to coat the elbow and slow down the process.

In addition, there are often bigger temperature swings in the the engine rooms on the hard as opposed to when in the sea. The ocean acts as a heat-sink and stabilises the temperature swings. Without the sea surrounding the boat, the temperatures can vary a surprising amount and this leads to condensation forming on the metal parts. Add in the relative humidity being higher in winter, if the exhaust isn't capped off and the valve train is open even slightly, the exhaust mixing elbow on a cold boat is not a nice place to be with cold, damp air swirling around.

I have pulled apart engines and found traces of water damage on main bearings which has been attributed to condensation droplets in the engine. Running the engine for short periods does not generate enough heat to evaporate the condensation, it will actually contribute worse as a small amount of heat is generated and then the engine is shut down which allows more condensation to form due to the temperature differences. It will do the same in the exhaust. This is one reason why the statement from a previous post is correct that it is actually worse to run an engine for short periods.
Click to expand...
I agree with all of that except that I am sceptical of any benefit of running a small amount of cold antifreeze through the engine in the hope that some of it will reduce corrosion in the elbow. The elbow spends all its life being attacked by hot salt water and combustion residue and after running the antifreeze solution it will do nothing to remove those corrosive elements and just evaporate. Equally in temperate climates like most of southern UK and New Zealand there is zero chance of anything in the cooling system freezing. Of course there may be localised conditions where freezing is a possibility and precautions may be needed. I leave my boat in the water all year round and in the last 30 years even in Poole the sea has frozen more than once but I have never seen temperatures anywhere near freezing in the engine box.
 
Tranona said:
I agree with all of that except that I am sceptical of any benefit of running a small amount of cold antifreeze through the engine in the hope that some of it will reduce corrosion in the elbow. The elbow spends all its life being attacked by hot salt water and combustion residue and after running the antifreeze solution it will do nothing to remove those corrosive elements and just evaporate. Equally in temperate climates like most of southern UK and New Zealand there is zero chance of anything in the cooling system freezing. Of course there may be localised conditions where freezing is a possibility and precautions may be needed. I leave my boat in the water all year round and in the last 30 years even in Poole the sea has frozen more than once but I have never seen temperatures anywhere near freezing in the engine box.
Click to expand...
I agree that the benefit is marginal at best, but a flush through with fresh water is definitely better than leaving salt water there for corrosion, and the a/f does help mitigate the increased risk of fresh water freezing. It certainly isn't a silver bullet, but it's one less cut to bleed.

I used to work around Poole and the S. Coast, it's amazing how much of a good job the sea does of preventing freezing conditions in the engine bay. Anecdotally, I worked on one (steel hulled) boat out of the water in Portsmouth that had ice in the bilge water. That was around 2010 when we had the very cold winter.
 
Mt Perkins 4-107 ... raw water cooled .... was lifted over 2yrs ago ... seacocks open to drain as much as possible from system.

I flushed system when ashore with 10ltrs of Antifreeze by pouring into seacock inlet (now closed of course) ... collected exhausted via a plastic drain pipe lent against boat covering exhaust into large bin ...

2yrs later ... the other day - boat was lifted into water after repairs and engine started in secs ... no problems except gearbox morse cable had broken !!
 
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