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On Apr 23, 2:13 pm, "Jim" wrote:
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I've been following this thread from the start but, even though I've
owned several sterndrives over the years, I'm a bit lost with the
mounting probs and brackets etc. The engines in mine were just
converted auto engines with a belt driven water pump already bolted
onto the front of the block as per usual.

On Tue, 22 Apr 08, "jamesgangnc" wrote:
the original merc
outdrive really is the bottom half of an outboard and that's where they
all
are on outboards.

But also keep in mind that the upper half is the bit that needs the
cooling and it's an "Inboard". None of which (straight inboards) need
an outboard type impeller. I've always wondered why the designers
didn't just get the cooling water through the bottom of the boat like
any normal straight inboard setup. One of the reasons I don't care for
sterndrives is it seems like they all have so many unnecessary
complexities designed into them. And cooling water intake is just one
of them. Maybe I'm missing something but what's the point in sucking
up water with the outdrive with all its additional parts and probs
when sucking it through a thru hull (like a zillion straight inboards)
would be so simple?

Rick

The Merc. small outdrive or any outboard water pump is immersed in water.
No need to suck, just push. I suspect that the engineers felt it
unnecessary
to reinvent a proven design when they adapted an outboard lower to an
inboard engine. Later when FWC and high HP engines came along they found
the
little outboard water pump couldn't deliver the needed volume of cooling
water. Back to the drawing board for a new solution.- Hide quoted text -

- Show quoted text -

The inside water pumps are basically the same design rubber vaned
pumps. All of them will self prime if needed and the distance is not
far.

I don't think the internal pumps are self priming. I would consider changing
my mind on that if I could see some proof.