raw water to freshwater cooling conversion

[Incantation]

So I am looking at picking up a boat with a yanmar 2QM15 motor; currently she is raw water cooled and this concerns me from the standpoint of longevity; I understand that there are also motors that run freshwater cooling with a heat exchanger.

I'm wondering if anyone has undergone this conversion and if so, if they could shed some light on how I should go about it, if at all?

In theory it sounds pretty simple.. I'd need a heat exchanger, expansion tank, another water pump, and the requisite lines/clamps/etc. Is there anything else I'd need?

Any insight and/or links to DIY guides, sites with parts etc would be greatly appreciated.

Thanks!
Inc

[SJ34]

All the parts can be ordered directly from Yanmar, just be ready to spend lots of cash. I just replaced my mixing elbow for $151 and that was the cheap one. The gaskets and o-rings for the exchanger were another $100. You may be able to retrofit an aftermarket heat exchanger but Yanmar makes that very difficult to do.

Is the boat in salt or fresh water?

[Faster]

Seakamp Engineering in nearby Bellingham makes a wide variety of small heat exchangers, also check AAA Marine Parts' website (Tacoma)

Something like this would probably do:

500805 Orca 4JH3E Yanmar external replacement heat exchanger equivelant replaces manifold cooling CALL FOR PRICING

New Page 0

AAA MARINE PARTS WHOLESALE

[jrd22]

I wonder if some of the boat yards might have used parts from take outs that you could use? Might be worth making a few calls to see if anyone has a used engine that was fresh water cooled that you could get the necessary parts off.

[Incantation]

All great suggestions.. thanks guys.

SJ34 the boat has been in salt water her whole life.. and the motor was installed in '85; I'm unsure of its history prior to then as I understand its production ended around '80.

If I do end up doing this I will document it with photos and a little DIY so I can give back to the community.. sailnet is proving an invaluable resource I just wish I was qualified to give advice instead of being such a leech.. lol

[MARC2012]

There is someone selling salvaged stuff on cruisers forum.You might give him a try.From a yard that dismantles boats left there.marc

[tommays]

You would have to do a HD scale removal as the bits love to clog the exchanger tubes when a motor has been raw water cooled a long time

[Incantation]

HD = heavy duty?

Not finding much regarding scale removal. I've read it involves using a harsh chemical.. can someone shed some light here? I'd like to do it in as environmentally friendly way as possible so if there is an alternative to using chemicals that would be preferred..