BoatBanter.com - View Single Post - RW Cooled Universal Diesel---Should I Convert to FWC?

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On Fri, 8 Aug 2014 18:28:27 -0700 (PDT), wrote:

On Wednesday, March 24, 1999 4:00:00 AM UTC-4, Timothy Cote wrote:
Hi All!

I'm the new proud owner of an '82 Pearson 28 which came complete with a
raw water cooled 11HP Universal Diesel (Model 15, 5411). Shortly after
purchase the exhaust manifold was found to be completely trashed, and it
cost about $500 to replace. I'm still not putting out any H20 on the
backside and the temp rises to about 180 before I get scared and shut it
down, I expect this is the thermostat and will replace it and further
investigate on Friday.

Can I convert this gem to fresh water? What will it cost? Is it worth
it for an engine I've not maintained up till now? Is there some way to
de-scale the innards durring conversion? Has someone assembled a
conversion kit?

Thanks in advance. Please reply by email as well as newsgroup.

Tim Cote
Takoma Park, MD

Yes, there is a de-scaling treatment. I do not know the exact details
but it is an acid and the technique is to remove the inlet hose and
run the engine slowly until you fill the engine with the acid mix.
Shut down and let it soak for a while. After the soak reconnect the
water line and restart to flush the acid mix completely out of the
engine.

I first heard of it from an Australian bloke who said that it was
commonly used by fishing boats. He de-scaled his 3 cylinder Yanmar
engine once a year.

Conversion to fresh water cooling is a bit of work. You need a heat
exchanger and a header tank and a raw water pump - this is in addition
to the normal engine water pump. The engine driven raw water pump
pumps sea water through the heat exchanger and than usually out the
exhaust . the engine driven water pump circulates fresh water from the
header tank through the engine block and heat exchanger and back to
the header tank.

180 degrees F is not excessively hot for a water cooled engine.

I would just like to say I have just finished changing my 5411 for a z600. It works but you cant use the alt bracket and the temp sender.We had to take part from 5411 like the exhaust studs the exhaust manifold. We also had to use the flywheel off the 5411.I closed off the lower water pump for the fresh water.I used my raw water pump to make the z600 raw water.I live in the great lakes we dont have salt so the head looks great for being 32 years old. I have the engine minus the oil pan and the valve cover I used the decompression from the 5411. This will work fine for fresh water only.
--
Cheers,

Bruce in Bangkok