Making an engine flusher system for antifreeze in the winter..

[wipe_out]

Hi,

I like to use the boat in the winter so I don't want the hassle of properly "winterising" the engine after each use because it's a hassle.. So I want to make a "quick flush" system that I can use to pump some antifreeze around the raw water cooled engine after use.. We are dry stacked in the winter so this is relatively easy in terms of access..

Idea at this stage is to get a long narrow and fairly shallow plastic box that can go under the outdrive from the transom to the prop to catch the circulating antifreeze.. This will be pumped back into the earmuffs to recirculate until I am happy it's completely circulated..

So the process would be a fresh water flush from the hose to clear the salt and get the engine to temperature.. Then place the box and put about 10l of antifreeze into it.. Connect the pump to the earmuffs and run the engine again to circulate the antifreeze.. Once done collect up the antifreeze for the next use (I know it will be a little diluted but still means I can get a fair number of uses out of it before it needs replacing)..

Has anyone tried anything like this?

Probably the main thing I am not sure about is which pump is best suited to the job.. A bilge pump would give high volume of water at low pressure which might be ok since the raw water pump on the engine would assist in pumping the water around.. Alternatively an in-line pump would deliver higher pressure at al lower flow rate.. The in-line pumps seem to have a short duty cycle though of about 10-15 min which should be enough but I would prefer to be able to run it as long as I like..

Any thoughts of the pump selection?

 

[Ex marine industry]

You face two potential problems
If you pump water into the cooling system with the engine not running you run the risk of water going the wrong way down the risers into the cylinders.
You can never be sure the engine has warmed up enough for the thermostat to open, only this allows antifreeze to circulate around the block. With the thermostat shut cooling water is diverted direct into the exhaust system.
My choice would be to fit good quality taps to the four drains on the manifold and block which can easily be left open whilst you’re away.

 

[wipe_out]

You face two potential problems
If you pump water into the cooling system with the engine not running you run the risk of water going the wrong way down the risers into the cylinders.
You can never be sure the engine has warmed up enough for the thermostat to open, only this allows antifreeze to circulate around the block. With the thermostat shut cooling water is diverted direct into the exhaust system.
My choice would be to fit good quality taps to the four drains on the manifold and block which can easily be left open whilst you’re away.

The taps might be an additional plan.. What taps would you suggest? and where could I get them?

My flusher plan would be to have the engine running while flushing through with antifreeze.. My theory was that the recirculating antifreeze would get warm quite quickly so the engine would have warm water cooling it and so would get hot enough to open the thermostat quite quickly and would be pre-warmed from the hose flush.. Obviously I would have to watch the temperature and shut it down before it got too hot..

Your point is valid though so maybe the high volume low pressure of the bilge pump is better than the in-line higher pressure pump.. Of course the in-line pump would be similar flow and pressure to a normal tap which has no problem with earmuffs so it probably wouldn't be an issue either..

 

[annageek]

Hi,

I like to use the boat in the winter so I don't want the hassle of properly "winterising" the engine after each use because it's a hassle.. So I want to make a "quick flush" system that I can use to pump some antifreeze around the raw water cooled engine after use.. We are dry stacked in the winter so this is relatively easy in terms of access..

Idea at this stage is to get a long narrow and fairly shallow plastic box that can go under the outdrive from the transom to the prop to catch the circulating antifreeze.. This will be pumped back into the earmuffs to recirculate until I am happy it's completely circulated..

So the process would be a fresh water flush from the hose to clear the salt and get the engine to temperature.. Then place the box and put about 10l of antifreeze into it.. Connect the pump to the earmuffs and run the engine again to circulate the antifreeze.. Once done collect up the antifreeze for the next use (I know it will be a little diluted but still means I can get a fair number of uses out of it before it needs replacing)..

Has anyone tried anything like this?

Probably the main thing I am not sure about is which pump is best suited to the job.. A bilge pump would give high volume of water at low pressure which might be ok since the raw water pump on the engine would assist in pumping the water around.. Alternatively an in-line pump would deliver higher pressure at al lower flow rate.. The in-line pumps seem to have a short duty cycle though of about 10-15 min which should be enough but I would prefer to be able to run it as long as I like..

Any thoughts of the pump selection?

If you do go with your idea, would it not be better to have a smaller 'catch' tank at the bottom and pump up to a header tank that feeds your water intake? This way you can run with more surplus capacity of AF incase the pump isn't coping so well / not pumping at sufficient rate then you get some warning rather than potentially running dry / partially dry without realising. I realise this complicates the pump selection though, as you you need a high rate pump (bilge sounds the best to me) that'll pump at reasonable rate to 1.5m of head or so.

This solves the.problem with water being pumped into a non running engine too, doesnt it?

 

[lynall]

Buy a neutra salt kit and just run anti freeze in the dosing tank instead of neutra salt.
Google image it, loads of info out there.

 

[ExcaliburII]

Idea at this stage is to get a long narrow and fairly shallow plastic box that can go under the outdrive from the transom to the prop to catch the circulating antifreeze.

I used to winterize Excalibur II's engine using this method with the boat on its trailer. However, your shallow box turned out to be a full sized domestic cold water tank which needed to be filled almost to the brim to get the level above the water inlet on the leg. Your recirculating pump idea would obviously cut down on the volume of water/antifreeze needed, but you may still need quite a big tank to catch all the run off and spatter coming out of the exhaust. Excalibur II had an Alpha 1 drive, with the exhaust bellows replaced with a straight tube as recommended by Mercruiser, so not sealed to the leg and a lot of water came out around the transom shield and sprayed everywhere. The noise of the unsilenced burbling V8 was glorious though.

 

[spannerman]

The easiest way to get the antifreeze mix into the engine at the correct rate is how we do in the workshop, we use a set off muffs with a few feet of hose leading up to a funnel which is tied to the back of the boat, usually a cleat and we simply pour the mix in from a bucket while the engine is running, you can still catch it as it comes out with a box to reuse if you wish.

 

[jimmy_the_builder]

http://www.flushsok.co.uk/

 

[aquapower]

http://www.flushsok.co.uk/

Just a PITA having to remove props every time but otherwise could be good solution.

When I had my V6 I would drain block by removing bung, and then run up with antifreeze mix going in via muffs from a can on the bathing platform, all done in no more than 10 mins.

 

[wipe_out]

If you do go with your idea, would it not be better to have a smaller 'catch' tank at the bottom and pump up to a header tank that feeds your water intake? This way you can run with more surplus capacity of AF incase the pump isn't coping so well / not pumping at sufficient rate then you get some warning rather than potentially running dry / partially dry without realising. I realise this complicates the pump selection though, as you you need a high rate pump (bilge sounds the best to me) that'll pump at reasonable rate to 1.5m of head or so.

This solves the.problem with water being pumped into a non running engine too, doesnt it?

Yes, I did think of this as an option as well..

Thought I would try without the "header" tank in the first instance and see if it worked.. Can always add the header tank later if it's needed..

 

[tribblehunter]

Nice to see the FlushSok mentioned here.

Being the inventor and proprietor of the FlushSok I am bound to be biased, so all I will say is it works well, gets engines up to temperature, can be used with various fluids for protection and cleaning, and once used a couple of times removing props becomes less of a PITA.

Looking into setting up hire locations around the UK in the new year so getting your hands on one may become much easier.