Emergency bilge suction

[Martinhilldpo]

I have read a couple of mentions of adding a suction line to the bilge from the engine cooling intake as a last ditch emergency bilge pump. This sounds like a wonderful idea to me. Does anyone know how many gph my 10hp Yamnar might suck up at say about 2000 rpm? Also has anyone considered leaving the sea suction cracked slightly open while pumping the bilge like this to avoid running the pump dry?

Please understand that I am NOT considering this as a routine solution, more as an additional bilge pump for use during dire emergency holy crap moments.

Thanks in advance, Martin.

[Steve Laume]

This always seemed like a horrible idea to me. Even if it can pump some water, your engine is not a bilge pump.

In a situation where you are taking on water, you want to be able to quickly activate a reliable and powerful bilge pump then move on to finding the leak and stopping it. Messing around with starting the engine, opening the engine cover and flipping a valve to try to suck some bilge water through your cooling system is not the most effective means of accomplishing this. Best case is that you will move a little water after wasting a bunch of valuable time. Worst case is that you fry your engine after it clogs or runs dry while you are busy trying to find the leak that has now had more time to fill the boat. This may well happen about the time you have decided your best course of action is to run the boat up on the beach to keep her from sinking. But now you have no motor.

For a couple of hundred dollars for a pump in the 2000 to 3000GPH range with a manual switch 1&1/2" hose and a through hull you can install a system that will be far more effective and will work at the flip of a switch.

The whole idea of using the engine as a last resort might have stemmed from a time when there were not any electric bilge pumps. If you had a big old raw water cooled engine in a smaller boat with only a manual bilge pump then this might seem like a good idea.

Raven's engine, propels her when needed, charges the batteries and heats the hot water. It does a pretty good job of these things but I would never expect it to be able to make a meaningful contribution to dewatering the boat, unless it was to keep the batteries charged up, Steve.

[Maine_Buzzard]

At best a small diesel will move 60-80 gph. Cooling water intake is totally insufficient for dewatering a boat, and just as likely to be the cause of the leak in the first place.

+1 on having a good electrical bilge pump and a bigass Edson hand action pump.

http://www.edsonpumps.com/pumps_dia/manual.php#30GPM

Nothing is faster than a sailor with a bucket!

[Bob Lascelles]

Hi Martin,

I just winterized my 1GM. I did this by warming up the engine with fresh water and then letting the raw water pump suck up environmentally safe antifreeze from a bucket to fully flush the water out of the engine and water lift muffler and eject out the exhaust (I remove the thermostat for the process). I pumped about 3 gallons to complete the process. Assuming my 1GM is typical, it only pumps between one and two gallons a minute at 2/3rds throttle (about 2000 rpm).

All the best,

[Martinhilldpo]

Hi Bob

Thanks for that. I thought it sounded like a good idea but for such a low volume it doesnt really seem worth it, I think I will drop that idea.

I have a list as long as my arm of things to do to my new 25D anyway, its not like I am going to be bored!

Thanks again

Martin.