| Author |
Message |
    
louq
Member
Username: louq
Post Number: 4
Registered: 09-2010
| | Posted on Tuesday, December 29, 2015 - 08:42 pm: | 
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I want to run fresh water cooling and was planning to use a couple of 1/2" copper pipes along the keel.
I have a three gallon holding tank for the cooling.
How many 10' copper pipes do you all think I need to keep this 5HP cool. The ocean around here is from 68-85 degrees.
The boat is a very heavy 16' fiberglass Cuban boat.
Thanks,
Lou |
miro
Senior Member
Username: miro
Post Number: 836
Registered: 11-2001
| | Posted on Wednesday, December 30, 2015 - 09:58 pm: |
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Each run ( 10 ft up and 10 ft back) is about 3.2 sq ft of surface are.
I reckon that 2 runs (40 ft altogether) should be more than adequate to keep that engine cooled.
I would connect the 2 runs in parallel.
Generally, most old marine engines are cooled too much even when they are working flat out full throttle.
But I expect that you will not likely be doing that in a 16 ft boat.
The so-called hull speed of a 16 ft displacement hull is about 5 mph. You CAN get the hull to go faster, but you'll be using a heck of a lot of power for almost no increase in speed.
I did some testing on a 16 ft displacement hull several months ago, and I found that the prop was making about 1/2 HP, driven by a ( supposed) 3 HP engine. I think the 3 HP was mostly made up of marketing hype.
Sounds like you'll have a nice cruising boat.
Miro |
louq
Member
Username: louq
Post Number: 5
Registered: 09-2010
| | Posted on Wednesday, December 30, 2015 - 10:34 pm: |
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Miro,
Thanks for the reply.
I was surprised that inlet on the pump on the engine is only 3/8". The boat is 16' displacement hull also, but very heavy (well over 1000 and closer to two). By parallel do you mean to go thru the bottom and Y into two pipes returning and going to a Y before going back thru the hull?
Lou |
miro
Senior Member
Username: miro
Post Number: 837
Registered: 11-2001
| | Posted on Thursday, December 31, 2015 - 07:47 am: |
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Yes, .
You don't need to make the pipe up to the Y any bigger than the pipes that you will be using for the keel cooler. It doesn't need to flow very fast.
I'd also suggest that you use a solution of water and anti-freeze.
That way you won't have to drain it for the winter, plus you'll get some anti-corrosion protection for the innards of your system.
Miro |
louq
Member
Username: louq
Post Number: 6
Registered: 09-2010
| | Posted on Thursday, December 31, 2015 - 10:06 am: |
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We are in Florida so the anti freeze will be for corrosion control.
Lou |
