Anybody converted a VP 2002 from fresh water to raw water cooling?

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rick-lamb

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So... the heat exchanger on my Volvo Penta 2002 (1991) has reached the end of it's life.
I took it to a local radiator shop to repair a leak and they pressure tested it and say they can't fix it.

Re-fitting to turn the engine over and now the circulating pump is ceased.

Rather than pay $2000 to replace parts on an old engine I've been looking at converting to raw water cooling.

It seems pretty simple, a few pipes and seals, a new thermostat, comes to about $300 at Volvo's prices.
More than I'd like to spend if it isn't going to work, but far more reasonable for an engine that I'm likely to replace in a few years.

Am I missing anything? Anybody ever tried it?
 
When my son Owen worked for Sunsail he did this many times. The seals and bits of copper pipe were always leaking, partly thanks to attention from the punters, and he found it easier to make them raw water cooled. It seems there are no light alloys in the engine that might corrode.
 
Can you not buy a used but good cooler on ebay or locally? Even if not specific to your engine. Once you put salt water through the block it is a slippery slope to the end of the engine.
 
I always thought 2002 & 2003 engines were always raw water cooled. Certainly my 2003 was so where the problem?
 
cryan: Not often, there happens to be one going for $750 right now in the U.S. ("This unit is being sold as is, with no warranty and no return.")
The cooling system is Volvo designed and patented and not easy to add a custom cooler to.

doris: Yes lot's seem to be, I just want to know that an engine that originally came with the optional fresh water cooling can still be converted back easily.
I've started to create a list of all the parts needed.
 
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doris said:
I always thought 2002 & 2003 engines were always raw water cooled. Certainly my 2003 was so where the problem?
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You could have either, but think the majority are raw water cooled. So, indeed there won't be any problem in principle, but think the pipework needs changing.
 
cryan said:
Can you not buy a used but good cooler on ebay or locally? Even if not specific to your engine. Once you put salt water through the block it is a slippery slope to the end of the engine.
Click to expand...

I have a VP2002. When I bought my current boat it was 8 years old. I made enquiries at the local Volvo agent about buying the conversion kit (then about £500 IIRC) to convert it to fresh water cooling. Their opinion was "with an engine as old as that, not worth it". So I didn't, but have since wondered whether that was the right decision. Now, 16 years later, it has started to overheat so next week I plan to introduce its waterways to some HCl. If the worst happens I have a complete spare 2002 in the garage that I bought for £250 a few years ago.
 
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This is the parts list I've come up with, anybody have any more info on the out of production clamp on the sea water pump to engine block connection?

Sea water pump to engine block connection
Hose connection 840732
Sealing ring 418445
Clamp Out of production Obsolete part ???
Hexagon screw 955269

Engine block to exhaust elbow connection
Hexagon screw 955269
Clamp 840676
Clamp 840676
Hexagon screw 955269
Pipe 840719

Thermostat to exhaust elbow connection
Clamp Out of production Obsolete part - (looks same as on freshwater engine)
Hexagon screw 955269
Sealing ring 418445
Sealing ring 418411
Coolant pipe 840679


60 degree thermostat
Thermostat kit 877355
Sealing ring 416033

Smaller belt for Alternator without circulating pmp
V-belt 966900
Tensioner 840593
Hexagon screw 955301
Spring washer 941907

Zinc for engine
Plug 838928
Anode 838929

Plug for fresh water inlet on engine block
Sealing ring 418411
Plug 840677
 
doris said:
I always thought 2002 & 2003 engines were always raw water cooled. Certainly my 2003 was so where the problem?
Click to expand...

It is no problem. Many were SW cooled. Maybe the Sea water in Fife has killer bugs :) Just a matter of piping up and securing the pipes correctly and fitting the correct thermostat. The pipe connection seals can be a PITA.
 
DaveS said:
I have a VP2002. When I bought my current boat it was 8 years old. I made enquiries at the local Volvo agent about buying the conversion kit (then about £500 IIRC) to convert it to fresh water cooling. Their opinion was "with an engine as old as that, not worth it". So I didn't, but have since wondered whether that was the right decision. Now, 16 years later, it has started to overheat so next week I plan to introduce its waterways to some HCl. If the worst happens I have a complete spare 2002 in the garage that I bought for £250 a few years ago.
Click to expand...

I've heard before you should use Phosphoric Acid rather than HCl - a little less corrosive.
 
DaveS said:
I have a VP2002. Now, 16 years later, it has started to overheat so next week I plan to introduce its waterways to some HCl.
Click to expand...

Like yourself, I am a long term owner (16 years).

Just a thought, you are probably aware that their is a copper pipe going through the block where water always passes irrespective of the coolant temperature.

Any blockage is liable to be in the engine galleries circuits which then lead to the thermostat and then into the exhaust elbow. I found it essential that the thermostat must be taken out when using brick cleaner to have any effect on the blockage.

I found it easier just to take out the thermostat and cover , then pour the liquid in directly into the engine galleries. It is very comforting to see and hear all the fizz. Also, the drain plug is on the left hand side of the engine as you look at it, and you may have to shove a small screwdriver up there to let all the crud out. Mine is always blocked.

Apologies. Just realised that you have a VP2002 . I have a VP2001. Things might be arranged differently.

As an aside, I have always been led to believe that these engines were designed to be raw water cooled right from the start which is unusual. They therefore were designed much thicker in the waterways department than the usual engines which are converted for marine use. Can anyone confirm this ? .
 
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LONG_KEELER said:
Like yourself, I am a long term owner (16 years).

Just a thought, you are probably aware that their is a copper pipe going through the block where water always passes irrespective of the coolant temperature.

Any blockage is liable to be in the engine galleries circuits which then lead to the thermostat and then into the exhaust elbow. I found it essential that the thermostat must be taken out when using brick cleaner to have any effect on the blockage.

I found it easier just to take out the thermostat and cover , then pour the liquid in directly into the engine galleries. It is very comforting to see and hear all the fizz. Also, the drain plug is on the left hand side of the engine as you look at it, and you may have to shove a small screwdriver up there to let all the crud out. Mine is always blocked.

As an aside, I have always been led to believe that these engines were designed to be raw water cooled right from the start which is unusual. They therefore were designed much thicker in the waterways department than the usual engines which are converted for marine use.
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Apologies to the OP for drifting the thread somewhat, but experience from someone who has done this is very helpful. Have you a rough idea of the volume of coolant held in the engine up to thermostat level? Did you leave the acid in for a fixed time or just wait until the fizzing stopped? I had wondered about getting the engine up to temperature before starting, is this likely to be beneficial?

Yes, my drain plug was blocked on the only occasion I opened it, not by scale, but by what seemed like fine silt which I assumed it had acquired during the boat's first two years on a drying berth in Chichester Harbour.
 
VicS said:
or perhaps Rydlyme which I am sure must be HCl based but buffered and inhibited to to reduce the corrosiveness.

http://www.rydlymemarine.com/

http://www.rydlymemarine.co.uk/
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Thanks for that Vic. Yes, I had a look at that site yesterday. After some guff about the formula being commercially confidential, near the very bottom a list of hazardous materials shows only Hydrochloric Acid and Distilled Water (!).

Following other recommendations I also spent time looking at the Fernox site: their lime scale treatment says: Fernox DS-3 contains Sulphamic acid with inhibitors, indicators and non-foaming surfactants, and the blurb specifically states that cast iron and copper are not affected.

So I've been swithering, but there seem to be a number of reports of successful treatment using brick cleaning acid, i.e. hydrochloric - which I happen to already have. My only lingering doubt was whether HCl might attack the copper pipe which runs through the top of the water jacket. Going back some 45 years to 'O' chemistry ISTR that nitric acid was the favourite for attacking copper ( I have a vivid memory of a flat headed copper rivet on a puddle of nitric acid making a quite effective hovercraft...) but I would welcome views on whether HCl would significantly attack copper in a relatively short exposure.
 
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I doubt if a bit of brick cleaner will do much damage in a couple of hours, but you could always drop a piece of domestic copper pipe into a cupful to see what happens. That nitric acid you were playing with would have been a hellava lot stronger than anything you'd want to let near your engine.
 
Yes, hydrochloric acid has a negligible effect on copper and many of its alloys, especially in the concentrations that are available to most of us. HCl was one of the liquids I tried when trying to find a test for brass or bronze. Nothing was affected in the slightest after 20 minutes in about 15% acid.
 
DaveS said:
Apologies to the OP for drifting the thread somewhat, but experience from someone who has done this is very helpful. Have you a rough idea of the volume of coolant held in the engine up to thermostat level? Did you leave the acid in for a fixed time or just wait until the fizzing stopped? I had wondered about getting the engine up to temperature before starting, is this likely to be beneficial?

Yes, my drain plug was blocked on the only occasion I opened it, not by scale, but by what seemed like fine silt which I assumed it had acquired during the boat's first two years on a drying berth in Chichester Harbour.
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Hi Dave

Take a look at this link - http://www.ybw.com/forums/showthread.php?354841-Volvo-2000-series-Raw-water-cooling

PVB posted a very helpful plan of the cooling system of a 2002.

With regard to the amount of mixture to get up to the thermostat, it depends if you plug the ends of the copper tube through the block . I found it easier to disconnect fore and aft of the tube and place wooden bungs. I reckon I then filled up with about a pint and a half of liquid. That was for a VP2001.

The bungs arranged so that they leak a bit will tell you that the two 3mm drillings in the copper tube are now completely clear. These feed the galleries. Remember to take out the anode of the metal bung then replace before fizzing. After about 10 minutes the fizzing stopped and I started flushing with clean water. I don't know if you should leave it any longer but this has worked for me. Keep flushing until clear water from the drain plug.

With regard to the two 3mm drillings in the tube I have no idea how they really work. I can only guess that there is some kind of suction or venturi effect from the exhaust elbow that sucks the coolant through via the thermostat.

Best of luck
 
LONG_KEELER; said:
With regard to the two 3mm drillings in the tube I have no idea how they really work. I can only guess that there is some kind of suction or venturi effect from the exhaust elbow that sucks the coolant through via the thermostat.

Best of luck
Click to expand...

I have been trying to find the answer to this for months! I posted a request for the information some time ago and have consulted with professionals who repair Volvo engines. Nobody seems to know the answer. Your guess is as good as any other but I suspect that gas flow is not enough to draw water, unlike the reverse.
 
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