Running an inboard diesel ashore without cooling water?

[black mercury]

Worked in a yard for couple of years. Starting a motorboat that is sitting on blocks and shores is a no no. The boat could sit through a force 10 blowing through, but you start the engine and she will sure vibrate the shores from under her and if you were to rev the engine you would loose the boat immediately. Think of car with big engine sitting revving, you see the car leaning to one side as the engine is revved up, that is the engine trying to rotate the car on its mounts. You do that on a boat that has a lorry engine and it too tries to rotate the boat. But a yacht sitting on a stand/trailer/cradle, you could rev the engine all day and it won't move, no problem. A yacht supported by shores only, I would be cautious, depends on weight of boat etc. Seen an owner put his engine in gear, don't think he'll forget the screaming noise his cutless bearing made.

 

[DaveS]

Worked in a yard for couple of years. Starting a motorboat that is sitting on blocks and shores is a no no. The boat could sit through a force 10 blowing through, but you start the engine and she will sure vibrate the shores from under her and if you were to rev the engine you would loose the boat immediately. Think of car with big engine sitting revving, you see the car leaning to one side as the engine is revved up, that is the engine trying to rotate the car on its mounts. You do that on a boat that has a lorry engine and it too tries to rotate the boat. But a yacht sitting on a stand/trailer/cradle, you could rev the engine all day and it won't move, no problem. A yacht supported by shores only, I would be cautious, depends on weight of boat etc. Seen an owner put his engine in gear, don't think he'll forget the screaming noise his cutless bearing made.

I'm sure all yards will have their own rules, but where I am it's standard procedure to run the engine with the boat in shores to draw in anti-freeze from a bucket as part of the winter lay up. Shores are properly set up with cross bracing. Never seen a problem. Masts must be taken down, however, and no boats have fallen over yet.

 

[pheran]

I'm sure all yards will have their own rules, but where I am it's standard procedure to run the engine with the boat in shores to draw in anti-freeze from a bucket as part of the winter lay up.

But why don't you do this while the boat is still in the water and avoid the risk? I do and I know the capacity of the raw water system so only pump enough through to just fill it. Saves wasting expensive anti-freeze or contaminating the water. Its no problem to then tow or pole the boat to the lifting point.

 

[vyv_cox]

But why don't you do this while the boat is still in the water and avoid the risk? I do and I know the capacity of the raw water system so only pump enough through to just fill it. Saves wasting expensive anti-freeze or contaminating the water. Its no problem to then tow or pole the boat to the lifting point.

I suggest this is impossible. On a raw water cooled engine the thermostat has to be open to ensure that the antifreeze enters the block. Otherwise the only part that will receive antifreeze is the bypass, which is less than helpful. I guess that theoretically you might get the engine up to temperature, turn off the seacock, substitute a reservoir of antifreeze, run the engine for the calculated time to fill it with the solution and turn it off, but I suspect this to be asking too much in practice. Far more sensible to run the engine ashore on fresh water first, then add the antifreeze, catching the solution in a container and feeding it back to the engine.

Alternatively, drain it down, remove the thermostat and pour the solution in without running the engine, although again, it has not been flushed with fresh water.

 

[DaveS]

Reply to Pheran:

Because the system with us is that you prepare your boat to be lifted out, tell the yard it's ready, and sometime the following week they motor it to the hoist. Since the water is over 10m deep, I doubt they would welcome a suggestion of "poling" , and while they can tow (and do if they can't get an engine to start) this is chargeable.

On the subject of risk, the shoring is, as I said, done properly, and no boats have fallen over to date, despite some pretty severe winter storms.

 

[Pye_End]

Alternatively, drain it down, remove the thermostat and pour the solution in without running the engine, although again, it has not been flushed with fresh water.

If you can drain it down effectively, is there a need to fill it back up again with antifreeze?

 

[chewi]

I do this every year. I disconnect the hose from strainer to seawater pump, and put the end in abucket of water. The sea water pump sucks up the water from the bucket, and I use a garden hose to refill the bucket.
This prevents over pressuring the pump (and risking water into cylinders), and being able to see the water going in means being assured it is.
Then I change to glycol last thing and suck that in before draining down for the winter.

I run from a bucket too, but the OP was asking about running briefly with NO cooling at all. Not what I'd choose to do.

 

[Halo]

I do this every year. I disconnect the hose from strainer to seawater pump, and put the end in abucket of water. The sea water pump sucks up the water from the bucket, and I use a garden hose to refill the bucket.
This prevents over pressuring the pump (and risking water into cylinders), and being able to see the water going in means being assured it is.
Then I change to glycol last thing and suck that in before draining down for the winter.

+ 1 This is a good method
Myself I just take the top off the Vetus strainer and stand by with a watering can full of water. Get someone to crank her and when she fires up I pour in the water (or antifreeze mix when laying up) . No need to remove hoses etc
If running longer I open the sea cock then put a running hose pipe into the strainer (lid removed ) then start the engine and close the sea cock so that the hose puts water into the system. The revs can be adjusted to more or less balance the water taken by the engine
I would prefer any of the bove to running dry even for a 20 second period

 

[vyv_cox]

If you can drain it down effectively, is there a need to fill it back up again with antifreeze?

When I had a raw water cooled engine I used to flush it while it was still warm, drain it down and leave it. I never used antifreeze.

 

[pheran]

I suggest this is impossible. On a raw water cooled engine the thermostat has to be open to ensure that the antifreeze enters the block. Otherwise the only part that will receive antifreeze is the bypass, which is less than helpful. I guess that theoretically you might get the engine up to temperature, turn off the seacock, substitute a reservoir of antifreeze, run the engine for the calculated time to fill it with the solution and turn it off, but I suspect this to be asking too much in practice. Far more sensible to run the engine ashore on fresh water first, then add the antifreeze, catching the solution in a container and feeding it back to the engine.

Alternatively, drain it down, remove the thermostat and pour the solution in without running the engine, although again, it has not been flushed with fresh water.

I think you've misunderstood vic. I said 'raw water system' ie separate from the engines own water jacket which is cooled by heat exchangers between the two. The block is already filled with its own antifreeze mixture and the thermostat, open or closed is irrelevant. The pumped in 'bucket full' is there just to protect the heat exchanger, exhaust
muffler etc

 

[vyv_cox]

I think you've misunderstood vic. I said 'raw water system' ie separate from the engines own water jacket which is cooled by heat exchangers between the two. The block is already filled with its own antifreeze mixture and the thermostat, open or closed is irrelevant. The pumped in 'bucket full' is there just to protect the heat exchanger, exhaust
muffler etc

No, I didn't misunderstand, you said 'I know the capacity of my raw water system'. I think you meant 'sea water system' to differentiate it from the indirectly cooled fresh water plus antifreeze in the engine and heat exchanger. Why you would want to put antifreeze through the seawater side is beyond my understanding..

 

[pheran]

Reply to Pheran:

Because the system with us is that you prepare your boat to be lifted out, tell the yard it's ready, and sometime the following week they motor it to the hoist. Since the water is over 10m deep, I doubt they would welcome a suggestion of "poling" , and while they can tow (and do if they can't get an engine to start) this is chargeable.

On the subject of risk, the shoring is, as I said, done properly, and no boats have fallen over to date, despite some pretty severe winter storms.

OK. Ours is very much a do-it-yourself marina. We get together as a group and have to hire in and pay for a mobile crane for the lift out/lift in which obviously has to be on set dates. No 'I would like to go back in on xx/xx/xx' possibilities. Despite there being over 100 boats in the marina as a whole, all management do is impose conditions, collect money...............and moan a lot. There are no full-time staff but it is cheap by local standards!

 

[pheran]

No, I didn't misunderstand, you said 'I know the capacity of my raw water system'. I think you meant 'sea water system' to differentiate it from the indirectly cooled fresh water plus antifreeze in the engine and heat exchanger. Why you would want to put antifreeze through the seawater side is beyond my understanding..

OK. Where I come from and indeed in all of my boating career, both rag and stick and mobo, 'raw', 'sea', even 'river' water are synonymous. But no matter.

Why you would want to put antifreeze through the seawater side is beyond my understanding.

Really? As I said 'to protect the heat exchanger, exhaust muffler etc.' By definition, the heat exchangers are going to contain both 'engine water' (which already contains antifreeze) and raw/sea water that doesn't. On many boats, mine included, it is not possible to drain these components completely and thus they are exposed to the risk of freezing. Running an antifreeze mixture through this system expels the 'raw' water and replaces it with something that wont freeze, avoiding potential damage.

 

[JumbleDuck]

I suggest this is impossible. On a raw water cooled engine the thermostat has to be open to ensure that the antifreeze enters the block. Otherwise the only part that will receive antifreeze is the bypass, which is less than helpful. I guess that theoretically you might get the engine up to temperature, turn off the seacock, substitute a reservoir of antifreeze, run the engine for the calculated time to fill it with the solution and turn it off, but I suspect this to be asking too much in practice.

That's more or less what I do. By the time I have motored from my mooring to the lifting place in the adjacent marina the engine is nicely warmed up. When she's in position I stop the engine, whip off the sea water inlet hose from the cooling pump (1GM10), substitute a short length of hose into a bucket of fresh water and antifreeze, 50-50, then restart the engine and run until the water coming out the exhaust is bright blue. It sounds involved, but in practice it's about 5 minutes work and, it seems to me, an awful lot easier than faffing about with hoses on land, trying to get an idling engine to warm up.

 

[ditchcrawler]

With my raw water cooled engine I run it up whilst the boat is in the water until it is nice and warm with the thermostat open and the batteries are charged, take the top off the filter on top of the seacock and pour the 50/50 antifreeze mix into the filter until it comes out of the exhaust and then switch off.On tickover I can get the top off the filter but at higher revs there is too much suction.I also use the environmentally friendly pink antifreeze not the blue stuff.

 

[vyv_cox]

Really? As I said 'to protect the heat exchanger, exhaust muffler etc.' By definition, the heat exchangers are going to contain both 'engine water' (which already contains antifreeze) and raw/sea water that doesn't. On many boats, mine included, it is not possible to drain these components completely and thus they are exposed to the risk of freezing. Running an antifreeze mixture through this system expels the 'raw' water and replaces it with something that wont freeze, avoiding potential damage.

I prefer to ensure that my heat exchanger and trap are fully drained than relying on a rather 'hit or miss' method of getting antifreeze into them.

 

[CAPTAIN FANTASTIC]

With my raw water cooled engine I run it up whilst the boat is in the water until it is nice and warm with the thermostat open and the batteries are charged, take the top off the filter on top of the seacock and pour the 50/50 antifreeze mix into the filter until it comes out of the exhaust and then switch off.On tickover I can get the top off the filter but at higher revs there is too much suction.I also use the environmentally friendly pink antifreeze not the blue stuff.

I though the pink antifreeze could attack certain rubber seals in odler engines; it is suitable for the "new" generation engines.

 

[ditchcrawler]

I use Starbright non toxic antifreeze for marine engines.Says it is safe for rubbers and plastics etc.I buy mine from Seamark Nunn who are local to me.

 

[JumbleDuck]

I though the pink antifreeze could attack certain rubber seals in odler engines; it is suitable for the "new" generation engines.

I have been advised to avoid pink anitfreeze for my more, erm, mature cars. They contain acids, it seems, which can play havoc with all sorts of useful bits of engines unprepared for the assault.

 

[lw395]

Living on the South Coast, it is not very likely for the interior of the boat to get cold enough for long enough for the sea water to freeze.

But (rarity) I agree with, vyv, just drain the engine. You need to check the impeller anyway.
And you want to disconnect the coolant line from the exhaust.

If you want to flush the salt water circuit, connect another hose to the line that goes to the mixing elbow and just wash it all through without the motor running.