Which bilge pump?

[garbageguy]

When my engine comes out (again), I'd like to replace the bilge pump. Existing one is fine, but I have no idea how old it is, and I know it sat in some oil (see my thread on leaking long block if interested - that's why the engine is coming out again - to seal 'er up).

Suggestions on what bilge pump to get? Anything else I should consider doing when the engine is out?


1998 Wellcraft 240 SE

 

[Bondo]

Ayuh,.... The set up ya got looks Ok,.... How many Gph is that pump,..??

I like redundancy, so have 2 copies of yer set up, with 1000 gallon pumps,...

Stay away from the auto-pumps with the chip in 'em,...
They ran my batteries flat, to many times to count,....
They "Test" for water to often,...

Nows a good time to crawl in there, 'n push, poke, prod, jiggle, wiggle, 'n pound on Everything lookin' for future faults,.....

 

[garbageguy]

Thanks Bondo. I don't know haw many GPH it is, and won't be able to look at it til she comes out of storage, and the motor is pulled again. 1,000 gph sounds good, and thanks for the heads up on auto-pumps. For a second pump installed - plumb and wire it so only one could ever run at a time? Or is there a sample way to rig it so they both went on if water level gets over a certain depth?

Ya, last time it was out - I spent a bunch of time in the engine room (she wasn't in the water, but at least I was in the boat)

 

[fhhuber]

I'd size the pump for MORE than enough capacity to keep up if you forget the drain plug.

http://www.bethandevans.com/pdf/HoleSizeandFloodingtable.pdf

 

[Chris1956]

There are brands of bilge pumps that snap into brackets fastened to the hull. If they burn ut, you can snap in a new one. That kind of pump would keep you from pulling the engine, to replace it.

 

[JoLin]

I like the small pump/large pump (one or more) idea. Put a 500 gph pump in and mount it and the float switch as low in the bilge as you can get it. Mount one or more high capacity pumps low in the bilge, but mount their float switch(es) an inch or two higher.

The small pump takes care of rainwater, spray, etc. without running down your battery. If something bad happens and the water rises another inch or two the big pump(s) kick in.

Plumb each pump separately with its own drain hose and through-hull.

My .02

 

[fhhuber]

Note... you can never put in a pump big enough to deal with a worst case "I hit a stump" hole in the boat...

You just have to pick what would be the most likely issue... and that's the drain plug for outboards or the cooling water hose(s) bursting (hose clamp coming off) for an inboard.

 

[airshot]

Yep I have two pumps on my boat, one is low and another about 1 1/2" higher up. I carry two batteries, one for starting and one for all accessories. My accessory battery is a deep cycle made to run down and run for a long time. I have the lower pump on the deep cycle battery and the higher pump on the starting battery just in case. If you have dual batteries in your boat consider putting one pump on each battery for twice the run time in an emergency.

 

[Maclin]

If you go with two pumps, definitely plumb for separate outlets as JoLin and others have mentioned. If you go with just one replacing what you have, be aware of the outlet size. You probably have a 3/4" thru-hull now, larger flow pumps above 750gph go to a 1" size at some point.

 

[garbageguy]

Thanks for all the suggestions. Cold here again, so I have a little more time to ponder this

Note... you can never put in a pump big enough to deal with a worst case "I hit a stump" hole in the boat...

You just have to pick what would be the most likely issue... and that's the drain plug for outboards or the cooling water hose(s) bursting (hose clamp coming off) for an inboard.

This is an IO. So I should size for cooling water hose burst or clamp coming off? How to determine what that design rate is?

 

[fhhuber]

Worst case location...

Size of the pipe/hose, full shear. So you have water coming in from both ends.

See the chart I linked above for no pump driving the water. Use the rub rail as the waterline and the lowest inlet/outlet hole to get the depth.
(this is pessimistic... but with flooding, are you pessimistic enough about that wet stuff that is trying to kill you?)

A pump driving the water can multiply it, but its OK to assume you'll shut down the engine, stopping the cooling water pump. (because if you don't, the engine burns up)

 

[garbageguy]

Thanks again everybody. What brand bilge pump and float switch do you think is best? Any to stay away from?

 

[garbageguy]

update: I took out the existing Rule 1500 gph pump (still working) and the surepump float switch (all gummed up), and snapped in a new Rule 2000 gph pump (into existing bracket), installed a new float switch, wired it in exactly how the old ones were, crossed my fingers - and after the engine was replaced, etc, the new pump works just as it should

 

[hogbare35]

garbageguy
I once saw a set up where you tee into a cooling suction line , put a valve & strainer in the bilge . In a dire emergency you open valve & use engine water pump to help pump out water . Don't remember where I saw this , but been thinking about trying a set up like that for the extreme .

 

[garbageguy]

update: I took out the existing Rule 1500 gph pump (still working) and the surepump float switch (all gummed up), and snapped in a new Rule 2000 gph pump (into existing bracket), installed a new float switch, wired it in exactly how the old ones were, crossed my fingers - and after the engine was replaced, etc, the new pump works just as it should

another update:
The new Rule 2000 has been working intermittently this season. I have gone through the connections, and all seems to be OK. I even cut the power supply wire, checked it has power. Re-connected the wires, pump wouldn't run. Re-checked connections - good. Left pump manual switch by accident, and all of sudden it runs - yay!. Now it won't run by float or manual switch. Could it be the pump itself? Any suggestions what to do next?