Is it possible to bypass cooling system......

[Dave B]

Is it possible to bypass the cooling system (raw water) and add a large (bus style) heater core with fan assembly rated at 20,000 btu or larger and operate it as a radiator and interior heater by looping the water through this set up? I do not need to use it as a heater by any means but rather use the heat as the by product of cooling the coolant. I live in Kansas and use my boat all the time and hate to keep wasting antifreeze every time I want to play. (every weekend that the lake is ice free) Also, it only takes me about 5 to 10 minutes to get from my slip to open water so if this system would work for say long enough to get in and out, is this something that could work for the cold months? Keep in mind that I would install a series of bypass valves that would allow me to open up to raw water if I saw a temperature problem. Any body ever think this through? My boat is a Catalina 30 with LOTS of engine access and numerous locations for installation either permanent or temporary (seasonal) I would use this ONLY for months that I winterize.

[Marian Claire]

With no water entering the wet/dry junction the exhaust line down stream could get rather hot. More thoughts later. Dan S/V Marian Claire

[ndutton]

I see a few issues that could be deal breakers. Most importantly is uncooled exhaust. Without raw water injection, your exhaust line is going to get really hot and that includes the aqualift muffler, the areas behind the stove niche and ice box, through the port locker and to the transom exhaust fitting.

Then there's the issue of cooling efficiency. Fluids transfer heat between each other (i.e. heat exchanger) 25 times more efficiently than fluid and air (as in the case of the suggested heater core). That's why small heat exchangers do such a good job.

If the foregoing isn't enough, you'll have to disengage the raw water pump to keep from destroying the impeller.

I'm thinking an antifreeze recovery system might be a better approach.

I see Dan was typing at the same time as me, he's a little faster on the post. We're on the same page.

[Dave B]

Bypass issue

My main concern overall is the cost (financially and environmentally) associated with winterizing every time I run the motor. Even with the heat exchanger kit through Moyer Marine, you have to winterize the exchanger. Could I install this system (heat exchanger)then evacuate the raw water with a compressor? I just hate to waste antifreeze all the time. There just has to be a way to make a totally "green" system. Help! By the way...what is the very best product for winterization?

[keelcooler]

You can use a little antifreeze to protect the pump and open the two block and one manifold plugs to drain out.

[rjm]

I have the same setup on my boat and wondered if I could just disconnect the fresh water pump (take the belt off) as the antifreeze runs threw the engine already with another pump...the only issue is the strainer and the heat exchanger..at present I have an Extreme electric heater that seems to work and even with that, I still antifreeze when it might get cold enough to do any damage or we start to loose power at the docks... either way it seems to be a pain at times to be able to use the boat all year..

[Marian Claire]

I use the RV type antifreeze. Non toxic, good to -50 and about 5 $ a gal at Wally World. Several boats, mine included, have T valves installed to allow for closing the raw water and drawing up the antifreeze. You could take it a step further and also have a T valve before the wet/dry junction. Then you could capture and reuse the antifreeze. Wish I could draw a sketch but I think it could work. Dan S/V Marian Claire “one coat closer to splashing”