Electric Centrifugal Raw Water Pump 12V

[James S]

Yeah...I can see how that would matter...

[HopCar]

I know some people use electric pumps to cool their generators. I've never heard of it being done on a main engine but I don't see why it wouldn't work. If you try it, please let us know how it works out. Aqualarm makes a switch that goes in the hose and will ring an alarm if the water stops flowing.

[capngeo]

I lost an impeller once and rigged my galley domestic distribution pump to cool the engine.... worked fine.

As long as you sourced a pump that was capable of continous service in an engine room environment, and made the suggested provisions for failure detection, I think it would work fine. A lot of big commercial vessels have electric cooling pumps

[Cheechako]

hmmm....if a dry exhaust my thermo switch idea wont work... Could you make an engine bracket to mount a more readily accessible belt drive raw pump? A lot of boats have hard to service raw pumps. It's not the end of the world... and as someone else says...you may be getting a whole new set of problems..

[bzsmarina]

Originally Posted by Sagittaire

The belt-driven impeller-type water pump">raw water pump on my 35 HP diesel engine is a problem:

1. Impeller cannot be inspected or changed without removing the pump, and the pump is hard to get at.
2. The belt cannot be adjusted without removing the pump, trying a new placement on the bracket, reinstall, and check the tension. (I know this is weird but is the way it is).

I'm thinking about installing a 12-volt electric centrifugal raw water pump to replace the engine-driven pump. I found a 12V stainless steel pump that has the required flow rate and head capacity. It will be mounted with a continuous flooded suction. (I would prefer a bronze pump, but can't find one that delivers 15 GPM at 10 ft head). I'll wire the pump with a relay to energize it whenever the engine ignition switch is "on."

I'll leave the engine-driven pump installed without the belt, with plugged hoses that I can swap out with the electric pump hoses, in case the electric pump fails. If electric pump fails, I'll remove the electric pump hoses, install the engine pump hoses, and connect the belt to the engine pump.

Any words of wisdom or caution about doing this?

hello, i was thinking of doing the same thing. i have a jabsco crank mount pump. all you can get for it anymore is the impeller. mine needs bearings and seals that are not available. what kind and what web site is the stainless pump you found? sounds like the pump i would like to try also. plus i am sure there are some hp`s to be gained by changing to 12 volt.

[Sagittaire]

HopCar: I am half-way through the retrofit. Will let you know how it works out. I am keeping the engine-driven raw water pump on standby, with capped hoses and belt ready to re-install, in case the elec pump fails. Easy to do this and provides redundancy (not immediate, but short time to implement). I have already installed the Aqualarm "Save Your Engine" raw water flow alarm kit.

capngeo: Thanks for the encouragement.

Cheechako: You would have to see my engine room to understand that retrofitting the existing raw water pump for easy belt adjustment and impeller servicing is not an option.

bzsmarina: I am using a Jabsco 50840-0012 electric pump with stainless steel impeller and volute. I would prefer bronze, but can't find a 12V high flow/low head pump in bronze. There will be no significant HP savings, as the electric pump efficiency is similar to the engine-mounted pump efficiency. In fact, I may be using more HP since the electric pump is constant flow rate, whereas the engine pump flow and HP vary in direct proportion to engine RPM. Lower RPM results in less pump HP.

I don't think this Jabsco pump would work for engines larger than 35 to 50 HP. Oberdorfer makes a 12V pump with higher flow and head rating, but would probably not be suitable for engines larger than 70 HP (Depco Pump Co. has it). There are probably larger capacity 12V pumps, but I have not found them. One could use 120V pump if boat had a suitable inverter, but I would not trust reliability of this approach.