Closed cooling conversion with high hours

[sgs01]

The engines on my seadancer are both RWC. They have over 1600 hours on them but they have NEVER been anywhere near saltwater.

I've heard that high hour engines will have problems with a closed cooling conversion because of scale and rust building up and blocking the inner heat exchanger tubes, thus overheating the engines.

Is this doable? Because I'd really like to do this to be able to use the boat over the winter.

Thanks!

 

[BurgundyS24]

I dont think it would be a bad thing. Might want to look at some engine descaler or some sort of treatment for it first.... and do that a few times

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[BillK2632]

Definitely doable, but I would give some thought as to why - I would not worry about any existing rust scaling etc - in freshwater it is just not an issue. If the only reason you are considering this is the winter/freezing weather use, I would look at some other solutions. The closed cooling is only going to cover the engine block, you still have to protect the manifolds which would still have freshwater in them. If the boat is in the water and on shorepower, I would really look at a bilge heater - in the south (I am on Lake Norman) it is a very good alternative to winterizing, most people who keep boats in the water in my area use the heaters. You do have to be prepared for that once every 5yr event where the power goes out during freezing temperature - but not that often here. To sum it up, closed cooling is definitely better and given two boats exactly the same except one is closed cooling, of course I would take the closed cooling. If it's an option when buying new, probably a good idea in freshwater, a must in saltwater. An aftermarket conversion on a boat older than one or two years, unless it is moving from freshwater to saltwater, probably not much benefit - you do something like this because you want to (nothing wrong with that), not because it is needed.

 

[sgs01]

I've thought about a bilge heater, but I live over 100 miles from my boat and my boat does not have a genset so I am totally at the mercy of the shore power at the marina, which is in Chattanooga.

With this winter predicted to be as bad as it is, using a bilge heater would be a huge gamble for me.

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[BillK2632]

So, like I said the closed cooling would solve the engine blocks, but you still have to protect the manifolds (maybe those are easy enough to drain after each use?) and the freshwater system (some people go ahead and winterize this and still use the boat).

When I had my 290 that stayed at a marina on Lake Norman, in the water year around. I didn't winterize and had a bilge heater - I worried all the time when it got cold. I put a thermometer in the bilge that recorded high/low temp, I was always surprised at how cold it had to get outside before the bilge cooled even below 45deg where the heater turned on. Really on all but the coldest days I don't think I even needed the heater. But, I was 30min away, not 100mi, so I understand where you are coming from. But, given the right conditions, an unprotected engine will crack, I've seen it and it's not pretty.

 

[sgs01]

With a full FWC system, the manifolds are cooled as well by the antifreeze. The only thing that is not is the risers and the auxiliary coolers like the oil cooler and transmission/reduction gear cooler.

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[BurgundyS24]

What engine/drive combo?

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[sgs01]

I have 2 Mercruiser MIE260 Bluewater direct drive inboards with Borg Warner VelvetDrive transmissions. Both engines are currently raw water cooled.

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[sgs01]

Another odd thing is that I have transmission fluid coolers but I don't have any oil coolers.

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[dpmulvey]

IMO, you're throwing good money after bad. You don't mention what lake, but what happens at the lake in winter? Bad winter...ice...no boating. Does it get lowered in the winter? What does the marina do with its docks? How cold are we expecting in the ATL area.

My money says that from January through March the boat won't get used 8 times max. That's a lot of money per use. If you insist on using her throughout the winter, get a couple of extreme heaters in the ER and be done with it. The whole concept of it can be blown apart in a night is nonsense in your area. It would take 4-5 days of continuous 20* temps to crack a block.

 

[sgs01]

There are 2 problems with bilge heaters for me.

1. My boat does not have a genset or inverter.
2. I live in the Atlanta area. My boat stays on Lake Chicamauga near Chattanooga. Its over a 100 mile drive for me to get there to do an emergency winterization.

The docks are floating at my Marina. They do draw the lake down but there is plenty of water left.

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[dpmulvey]

There are 2 problems with bilge heaters for me.

1. My boat does not have a genset or inverter.
2. I live in the Atlanta area. My boat stays on Lake Chicamauga near Chattanooga. Its over a 100 mile drive for me to get there to do an emergency winterization.

The docks are floating at my Marina. They do draw the lake down but there is plenty of water left.

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An inverter wouldn't cut it. Your batteries would be dead in short order. Is there power to the docks? If so you'll be fine.

Unless you are running air evac systems (think Horizons), even with FWC, you are going to have to drain the blocks every time you use them with out an ER heater. I'm assuming if you are driving 2 hours each way, you are spending the weekend. How are you heating the cabin?

 

[Westie]

Unless you are running air evac systems (think Horizons), even with FWC, you are going to have to drain the blocks every time you use them with out an ER heater. I'm assuming if you are driving 2 hours each way, you are spending the weekend. How are you heating the cabin?

Can you explain why you have to drain the blocks if you have a FWC system?

 

[sgs01]

There is power to the docks but what happens when the power fails?

Also with FWC the blocks and manifolds are cooled by antifreeze. The only stuff that needs draining or filling with antifreeze are the risers and auxiliary oil and reduction gear coolers.

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[sgs01]

Can you explain why you have to drain the blocks if you have a FWC system?

I think he is thinking about the risers. Still have to drain those. Manifolds too if it's a half system.

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[Westie]

I think he is thinking about the risers. Still have to drain those. Manifolds too if it's a half system.

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Ya I think so too. I have a half system on my boat and it takes me about 10 minutes total to do what I call my fallization. We can get freezing temperatures here in the fall but some nice weather too. During that time I just drain the manifolds and remove the fuel cooler drain plug.

On my old boat I added a full system to it when the boat was already about 12 years old. It is a straight forward job. Took about a day to install all the components. Before I added the conversion I did flush the engine out with muriatic acid to remove the internal scale.

 

[sgs01]

An inverter wouldn't cut it. Your batteries would be dead in short order. Is there power to the docks? If so you'll be fine.

Unless you are running air evac systems (think Horizons), even with FWC, you are going to have to drain the blocks every time you use them with out an ER heater. I'm assuming if you are driving 2 hours each way, you are spending the weekend. How are you heating the cabin?

I don't spend the night on the boat. The boat does not have a.c. or heat (yet). Its about an hour drive. Its easy to spend the day there. Cabin climate control is nice, but it is a non-essential right now. Perhaps in the future.

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