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vic008

Keel cooled

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Why would you want to change it?
To change, you are going to need a Salt(Raw) water pump and an exhaust mixer. It is possible you will need a larger diameter exhaust to handle the extra water. To marinise the engine, you will need additionally and heat exchanger and you may want to include an exhaust manifold if you want to reduce the exhaust temperature in the engine room.
Obviously a hole in the Hull for the water entry, valve and a strainer and throw in all the required hose work and etc

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If it works I would think that closed circuit keel cooling would be great with no salt water in the motor. Pumping clean coolant around only.

+ 1   Keel cooling is by far the best solution for any inboard motor. You would need a very good reason to want to change it.

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Is a dry exhaust not on?(a few ex lifeboat engines popping up.)Including Bukh 28 hp twin,- never heard of before.

How about: what mods if had a turbo on that you didnt need?Remove easy?

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Dry exhaust shouldn't be a problem if it is insulated, A dry exhaust can be water jacketed and used for water heating.

A turbo can give you better mileage, excellent at constant revs. If removed the injector pump would likely need to be re-calibrated.

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You would need expert advice removing a Trubo. Some engines have lower compression to compensate for the extra air forced in, some don't. Removing the turbo on low compression engines only causes them to smoke and hard to start. Some it is nothing more than injector pump adjustment. Others may require different injectors to suit the required fuel dose. You will also lose about 50% of the rated power, maybe more.

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Before our time, Wild Bird had a keel cooled system for the engine (60hp Nissan). Had a 500 litre tank of fresh water low in the bilge. The previous owners had issues with the cooling being inadequate to let them develop more than about 40hp. This is a steel boat, so good thermal conductivity. They could get better in Winter when the sea water was a bit cooler. Boat was based North of Auckland. I suppose that a larger keel tank would help there, but say you had a 1000 litre cooling tank - you'd be lugging an additional 1000kg of water around all the time.

 

What we have now - which the previous owner installed - is a dry exhaust, fresh water engine cooling, a Savage heat exchanger with raw sea water supplied via a belt driven pump. Certainly works, and we can maintain cruising revs on the diesel for days at a time, going into adverse weather, with no abnormal temperatures.

 

From my point of view - this being my first boat with a dry exhaust system - there are a few drawbacks. The exhaust runs hotter, not a major issue for us. The exhaust system isn't muffled as effectively as it is with a wet exhaust. Depending on the position of the exhaust through hull and the direction of the breeze, the fumes can get quite unpleasant in the cockpit, not a problem when you are sailing, but you inevitably need to run the donk for a while at some point. Whether you have a system like ours, or a keel cooled system, they are all things  which will need to be considered.

 

For us, and it may well just be to do with the exhaust through hull location, the issue with fumes is enough to have us toying with changing over to a wet exhaust.

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