Engine Driven Bilge Pump

[TwoD83]

Greetings! I'm working on a plan to install a belt driven bilge pump off of the engine. I'm planning to use a 7860 GPH "trash" pump with an electromagnetic clutch from a car AC compressor. Does anyone have a similar setup? Any and all input welcome!

[mitiempo]

Commercial boats around here usually have something similar, but often hydraulic. Certainly possible. What kind of boat do you have?

[TwoD83]

Good to know. I have a Cheoy Lee Clipper 42 with a Perkins 4108 engine ~50 hp. I don't have hydraulics on the boat, electric should work fine.This pump will be in addition to two electric bilge pumps. The engine driven one will be meant to be the "oh crap, we're sinking!" pump. Every little bit helps. I will definately have some kind of manual back-up to the electric clutch, not sure yet what that will be.

[deniseO30]

Some people use the raw water pump and install a intake line from the bilge to a T in the intake line. I just wonder about the cost and trouble to install a pump so big it could save the boat compared to the actual risk of the boat sinking.

[TwoD83]

I thought about that, but I want the raw water pump to be dedicated for that purpose. Also, when the bilge valve starts leaking you'll either lose the prime on the raw water pump or leak into the bilge. The large centrifugal is also much more tolerant of debris and heavy duty. If there is a hole in the boat large enough to require a pump that size, chances are there will be a good bit of debris in the bilge. A larger pump can also double as a fire pump in an emergency. I plan to take the boat on some long distance/harsh environment sailing. Anything to keep her floating!

[CapitainMike]

Originally Posted by TwoD83

I thought about that, but I want the raw water pump to be dedicated for that purpose. Also, when the bilge valve starts leaking you'll either lose the prime on the raw water pump or leak into the bilge. The large centrifugal is also much more tolerant of debris and heavy duty. If there is a hole in the boat large enough to require a pump that size, chances are there will be a good bit of debris in the bilge. A larger pump can also double as a fire pump in an emergency. I plan to take the boat on some long distance/harsh environment sailing. Anything to keep her floating!

Why will the Bilge valve start leaking any more than the seacock that supplies the raw water coolant to the engine if your that concerned fit two two bilge valves in series. If you are going to fit a large pump to the engine don't forget a good strainer.

[deniseO30]

think I heard or read once that more boats sink at dock more then at sea.. "jus sayin"

[mitiempo]

They do, whether from snow load, cracked hoses, anti siphons that don't or something else. Neglect plays a big part.

[Minnewaska]

Originally Posted by deniseO30

think I heard or read once that more boats sink at dock more then at sea.. "jus sayin"

Probably the law of averages, since the average boat spends more time at dock than at sea.

However, when you are at sea, your odds of springing a leak are probably the same at the average boat at the dock. You should be less likely to actually sink, since you are there to close the seacock or turn on that badass engine driven bilge pump. Neat idea.

[Barquito]

badass engine driven bilge pump

I think what you need is a dedicated motor with a supercharger and fueled by nitro-methane

I think that sounds like a reasonable layer of security, especially if you can use it for other purposes (firefighting, washing dishes...)