emergency conversion fresh water pump to raw water?

[El Pinguino]

Originally Posted by Russian007

Your water pump craps out on the edge of the world, what to do? anyone have experience converting on the fly to pure raw water cooling?

It would depend rather a lot on the engine. You are toast if it is a Volvo MD17D or similar and you really do need to carry a spare pump.

I have worked around a lack of replacement impellor for the same engine's SW pump ( long story) by re-routing the SW via a shower sump pump and back through the sw pump which had its impellor removed. We used sections of the deck wash hose and some cobbled connections.

Maybe you could do that on the FW side of your engine.

[Pete7]

Originally Posted by rslifkin

If you're talking about converting a closed cooling engine to open cooling, you'd have some significant re-plumbing to do. On many engines, the coolant circulating pump is still needed even with a raw water setup (or you'd need to make further changes to avoid needing it). And then you'd have a salt contaminated engine when you're done, plus depending on what temperature the engine runs (unless you remove the thermostat) you may get massive amounts of salt buildup in the block and heads. Depending on the metals exposed to coolant you could end up with major corrosion too. Either one could be bad enough to require major work afterward (or worse).



Basically, this is just not feasible. With appropriate spare parts, etc. there's not going to be a cooling system failure that you could just easily band-aid by switching to raw water cooling.

Well, firstly the VP 200x series engines have the RW pump off the camshaft not via the alternator belt which is nice if the belt snaps. You loose the charging but the engine will continue to run quite happily for hours.

Secondly, running saltwater through an old cast iron engine block isn't a problem. If it was then all the RWC VP200x series would be scrap years ago. Ours is 33 this year. Yes we did a major flush last winter with diluted acid poured into the block via the thermostat housing for an hour once the flute in the cylinder head had been rodded out, but the flute wasn't as bad as I expected.

Lots of gurgling and black foam. Ran the engine, then popped the thermostat and anode back in and another flush. More white cloudy liquid with bits out of the exhaust, concretion perhaps? Now after a summer with 100 hours or so on it runs perfectly, saltwater cooled. Remember these engines were designed for RWC.

Could you engineer RWC in a remote location? yes particularly if you planned ahead and had a few bits in a kit ready to go.

Pete

[skipperpete]

Originally Posted by Russian007

I don't like salt water in my engine either but engines are easy to flush. We're talking Get-me-home situations here.

I think better maintenance and inspection might limit the need for an emergency cooling system, one of the routine checks of circulating pumps is to grab hold of that pulley with both hands to see if there’s any bearing looseness and then spinning the pulley to feel for roughness , noise , weep hole leaks and resistance to rotation( or lack of resistance if the mechanical seal is too slack).
At least you don’t need to carry a spare starter motor for the “remote location” breakdown mitigation plan.
Incidentally I found this offering from ABmarine[ATTACH]265704
Pete.

[Russian007]

Originally Posted by Patrick of M

This thread started as "your pump craps out at the edge of the world" . I suggest entreating some mermaids to harness the local fish or dolphins and tow you to safety.

You've obviously never been offshore. Everyone knows mermaids don't inhabit the Earth's edge. Common knowledge. Jesus.

[Patrick of M]

Originally Posted by Russian007

You've obviously never been offshore. Everyone knows mermaids don't inhabit the Earth's edge. Common knowledge. Jesus.

I can't help you if the mermaids don't come for you. They always come for me.... probably why they always arrive so quickly when I need them.

[skipgundlach]

My apologies for skipping ahead after the first dozen or so posts. I may have missed one or more similar replies.

It's pretty simple, and her new owner is beginning to get it, in conversations with fellow cruisers faced with a dilemma. He asks, because Flying Pig (the home I cruised for 15 years) does have, for those situations:

"What??? Why don't you undo two bolts and 4 clamps and mount your replacement???"

PS Alternators don't usually need clamps, so it's a bit less complicated ...

[captstu]

I had that happen relatively new boat with a poorly installed water pump">raw water pump. I was able to replumb so the freshwater pump drew the water in from the ocean, ran through the heat exchanger, ran through the block and ran out the exhaust. It only took about an hour to make a conversion and it ran fine for weeks

[Djarraluda]

Originally Posted by Russian007

Your water pump craps out on the edge of the world, what to do? anyone have experience converting on the fly to pure raw water cooling?

Yes, about 1985, we were on a Tayana 55 and gen set raw water pump failed, main engine had other issues and batteries fading as we cruised around northern Phillipines. Took a fresh water pump, remounted it to a board and piped it into the cooling water circuit.

All worked well that day. Next day, running the gen set again, it failed, the pump burnt itself out because it was not rated for continuous running.

So, by all means it will get you out of a sticky situation for a while, but..... a time limited option I am afraid.
Roger

[nmccubbin]

Lots of engines run with salt water cooling
Our old MD2B did
I do not like it, but using it for a few weeks while awaiting parts will probably do not harm

[kapnd]

Something else to consider in this scenario is that your belt will most likely need to be removed, if it hasn’t already shredded/burned up and fallen off.
This means no alternator output, so whatever electrical items needed to run the motor and navigate home will be drawing down the battery.
I have been in this situation, and was able to get home by splitting the raw water flow between the raw side and the coolant side, and discharging hot coolant side overboard. tapping into the coolant loop should be done in one location, cut a convenient hose where both cut ends will be accessible, attach raw water supply to one side feeding, and discharge from the other. Water pressure will provide circulation in lieu of the defunct pump, which will likely continue to leak.
Run the motor easy, you have substantially changed the cooling dynamics of the motor, and will have very little idea how your motor is liking that!
Old Mr Murphy works hard to make things like this happen at the worst possible moment, and you must McGuyver your way around him.

[Mr B]

I have a 12 volt hot water pump on my hot water tank from the engine,

$20-00 off Ebay,

I put a switch on it so it dont run all the time, Conserving my batterys,

It would possibly suck enough water thru it to cool the engine, Freshwater side,

Not a great deal of water goes thru the Freshwater side of the engine pump,



My thermostat on the freshwater side packed it in, I eventually had a pipe inside the hose to bring the temp up to running temp of the motor,

It had a max diam of about 3/8 of an inch, I had 120 Degrees instead of 160 Degrees, But it was enough to run the motor, 27 HP Diesel, 3 Cylinder,

Yes, I was a long way offshore,

[JPA Cate]

Twice, we used the dinghy inflating pump to pressurize a tank to get the contents out. So, I'd have to agree that Mc Guyvering is the way to go!

Ann