On Fri, 8 Jan 2010 10:40:52 -0800 (PST), Len
wrote:

Thanks for the replies.
@Mees,
The seawater in the engine blocks occurred with new, flat faced seals
which I suspect to "aquaplane" and let water through.
These were used by the mechanical shop. I will not use those again and
I'm back to the "V-shaped" seals.

@Steve
I normally run the engines (I have a twin engine motorsailer and BOTH
identical engines show the same problem...) below 2000 rpm.
With the last overhaul, every bearing was replaced even when the
bearing looked and felt OK.

@Bruce
I think your solution is the way I want to go.
Which brand centrifugal pump did you install?
Any pitfalls or more hints come to mind?

TIA, Len.

I used a centrifugal pump that is made in Thailand, but any well built
pump should suffice. I used a cast iron, 3/4" outlet, pump for about 8
- 9 years. Had some over heating problems and investigation showed
build-up of scale and corrosion in the inlet port of the pump. I
replaces it with a bronze pump, however 8 - 9 years service is not to
be sneered at, I'd reckon, and cheaper too.

In my case I replaced the port fwd. engine mount bracket, that bolts
to the engine, with a fabricated bracket that incorporates a flat
mount surface for the pump. The pump base is slotted to allow some
adjustment but actually, since installation I have never adjusted the
pump or replaced the vee belt that drives it from the engine's front
"fan belt pulley".

I don't remember whether I calculated pump RPM when I originally built
the system but I just had a look at it and I'd "eyeball" the ratio at
about 2 - 3 times engine speed.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)