I didn't mean to imply that as a hard fast rule. Everything is very
close coupled on my boat. It was the fact of the airlock being very
close to the pump so that the piping was still airbound when the pump
started cavitating in air.

Yes, the pump should be able to lift that far but you want an engine
cooling system to still function event when the pump impeller is
compromised by wear or air. Make everything as easy as possible for
it.

It's possible that I could have gotten the flow restored by going up
to maximum RPM for a while but I started assuming blockage or impeller
failure. It was a pretty exciting day and the implications of the big
heel angles didn't sink in till later. The suction is pretty low.

My seacock is right next to the strainer so I don't lose anything by
keeping it all self priming and easy flowing. If your strainer has to
be far from the seacock, then, by all means put it above the
waterline. Just don't have it right next to the engine with a short
hose running down from the strainer to the pump.

--

Roger Long



"Steve Lusardi" wrote in message
...
Roger, the lesson you learned is wrong if you think the strainer
should be below the water line. You immediately lose the ability to
clear blockages through the hull fitting. if you do. Any decent
rubber impeller pump will suck 2 meters of head if the tips are kept
wet by a post pump riser.
Steve

"Roger Long" wrote in message
...
Here's something about cooling water intakes I learned the hard way
last year even though, somewhere in the recesses of my mind, I'm
sure I knew
better at the time.

Http://Home.maine.rr.com/rlma/Strider0603.htm#cooling

BTW there was quite a bit of discussion here about the Aqualarm
when I was putting it in last year. My conclusion after a season
of sailing is that it functions well as an alert to total stoppage
but isn't much good, at least with small engines, at alerting you
to reductions in flow. Ironically, my only cooling water system
failure was caused by the alarm installation itself. At least it
told me though

Now that it's properly set up (or will be tomorrow) , I'm glad to
have it on my boat.

--

Roger Long