convert from sea water to fresh water cooling....

[john232]

.. I was wondering if other boaters have converted there sea water engine cooling system to fresh water enclosed units? Is it hard to do and is it worth the time and expense to do it? John.

[tahitisail]

John,
I looked into this for my yanmar 2 cyl and figured I only needed to bolt on another water pump and a heat converter and reroute the plumbing to make it work. This wouldn,t keep my exhaust manifold from salting up since I would still be dumping salt water into the hot exhaust gasses.
Looking into the water jacket when I change zincs I see a beautifully clean interior which is excellent for cooling the engine. In fact when I talked to two marine mechanics I was advised to leave well enough alone because the seawater cooling was, according to them, superior to fresh water cooling. Make sure you service your zincs!

[pjfsail]

John, I saw your message when you first posted it but have been so busy I just have not had time to reply. Please forgive me. I asked a similar question on 6/19/03 on this forum. Please go read the (21) responses and then get back to me and I''ll tell you what I know so far. You will have to hit the "NEXT 40" 11 times to get to June''s questions. Once there scroll down about 2/3 of the way and you will come to the question I asked, "MD3B volvo-Penta sea water to fresh water conversion." I took the advice seriously and have accomplished much more research on the topic and have started to buy parts to complete the task. I would be glad to tell you what I have found out since June. Regards, Peter

[elhanley]

Your converted engine would have a remote heat exchanger discharging the salt water into a mixing elbow in the exhaust downstream of the manifold tank. If configured correctly, salt water shouldn''t be able to get back to the engine.