"IanM" wrote in message
..
snipped.
If the problem is solved, I *might* consider reconnecting the bilge
pickup, but the amount of emergency seawater pumping this gives you is
minimal and a large mechanically or electrically driven pump would be a
far better idea.
more snippage

I think using the engine pump on bilge water is a very bad idea, not just ,
as you say, that the quantity pumped is minimal, but also because all sorts
of crud lie in bilges and do you really want to pump such 'stuff' through
you engine? Maybe you will create a blockage that will be a real PITA to
clear.
Also, unless you are in a position to sit there watching and turn back the
cock to sea water inlet at the precise moment before the bilge suction sucks
air you are going to send a lot of air into your engine which will create
local overheating and maybe an air lock or even a steam lock and maybe
crack the cylinder head when the cold water finally comes through.
I agree with your suggestion of an entirely seperate bilge pump of adequate
capacity.