Raw water cooled engines

[jenevers]

Did any Raw water cooled Engines actually circulate the raw water through the engine or did they all use heat exchangers?

[Tracy D'arth]

Yes, that's why they rot away and need anodes in the block.

[waterdog]

19 minutes ago, jenevers said:

Did any Raw water cooled Engines actually circulate the raw water through the engine or did they all use heat exchangers?

No idea, I'm sure someone will be along soon to give you a sensible answer. ?

[Tony Brooks]

35 minutes ago, Tracy D'arth said:

Yes, that's why they rot away and need anodes in the block.

And some marinised automotive engines did not seem to have  engine anodes. Maybe those using aluminium castings for water hoped the alloy would act as an anode and get eaten away - some did, especially exhaust elbows.

[Mad Harold]

2 hours ago, jenevers said:

Did any Raw water cooled Engines actually circulate the raw water through the engine or did they all use heat exchangers?

Yes.My last boat had a BMC 1500 and had that system.

Sucked canal water from under the counter,through a strainer and Vetus water filter with a Jabscoe pump,around the water jacket and spat it out at the side.

This system will usually be on older boats.Mine was built in 1978.

[restlessnomad]

tried to click on the post like an idiot... 

[roland elsdon]

My first boat had a Perkins d152. The water came in through pipes in the weed hatch lid, through a jabsco and straight out with the exhaust.

No thermostat. It always ran cold.

In the 2 years of ownership I had to replace several core plugs which rotted out. God knows what the internal water passages were like.

Built in 1977.

[jake_crew]

Our Gleniffer does.

 

I suspect Fulbournes does too.

[billh]

This  here Kelvin does. The water comes through a mud box to the engine and is ejected from the cylinder block to the  "bomb" silencer , passing out with the side  exhaust. In cold weather it makes a lot of steam,ok water vapour, ( the mixing and cooling in the silencer) and keeps the exhaust system reasonably cool and quiet. It draws many comments about overheating engines and/or  "is it a steam engine?". Well it's obviously been overheating for the last 72 years but still going?.

[Wide boat man]

My Perkings 4107 had raw water cooling and a bowman heat exchanger. raw canal water filtered pumped through the heat exchanger and out the exhaust the heat exchanger held the cooling water in an enclosed system and pressure cap and was toped up like a radiator so you could use antfreeze. wet exhaust used a belows type pipe very quiet and if the inlet blocked with weed or mud you could hear the water stop. What cooling system have you got?

[Man 'o Kent]

My old National was happy enough  for around 70 years then the new owner forgot to keep half an eye on the outflow.

 

No water = hot engine = thin oil =  lost oil = low oil =  melted white metal big ends . . .

 

Very sad.

[Tony Brooks]

47 minutes ago, Wide boat man said:

My Perkings 4107 had raw water cooling and a bowman heat exchanger. raw canal water filtered pumped through the heat exchanger and out the exhaust the heat exchanger held the cooling water in an enclosed system and pressure cap and was toped up like a radiator so you could use antfreeze. wet exhaust used a belows type pipe very quiet and if the inlet blocked with weed or mud you could hear the water stop. What cooling system have you got?

 

For future reference. your engine has indirect raw water cooling that I prefer to call heat exchanger cooling. I suspect that vast majority of cruisers and a fair few narrowboats use that system. That is not what the OP is asking about is direct raw water cooling where the canal/river/sea water actually circulates through the engine.

[David Mack]

1 hour ago, jake_crew said:

Our Gleniffer does.

 

I suspect Fulbournes does too.

 

Yes. Fulbourne's National takes in canal water through a mud box (filled with aquarium filter foam) then via the reciprocating pump, through the engine and out through the hull side, just below gunwale level, where it catches the feet of the unwary standing too close to the lockside, or occasionaly into freefall for 120 feet.

 

This arrangement is pretty typical of the proper marine engines originally fitted to working narrow boats (and countless fishing boats etc.), whereas indirect cooling is more a feature of engines derived from industrial and automotive base units.

[jenevers]

So do your raw water cooled engines have anodes somewhere?

[Tony Brooks]

The marine engines designed for sea use do like Bukh and Volvo Penta. Don't know about the Trad engines for narrowboats but I suspect not unless retro-fitted.

Edited June 4, 2020 by Tony Brooks

[Mad Harold]

3 minutes ago, jenevers said:

So do your raw water cooled engines have anodes somewhere?

Mine didn't.I have heard of core plugs rusting through,but didn't experience it.

This method of cooling (in my case) was extremely simple,but needed more attention than skin tanks.

Checking the inlet strainer and water filter I made a daily task as well as keeping an eye on the water outlet.The cleaning of the filters was not always necessary in that I could cruise on some canals for several days and the filters would be clear.But I remember the upper Peak Forest one Autumn was a carpet of leaves,and I was clearing the inlet strainer almost every hour.

A thoughtful previous owner of my boat had fitted a hose connection to one of the cylinder head blanking plugs,and every time I filled up with water I would put the hose on it and flush the water jacket.Usually got a few seconds of brownish water from the outlet (rust or sediment?) and then it would run clear.

I only owned the boat  for just over two years,so am not in a position to say what this system is like longer term,except that the boat was built in 1978 and I have no reason to believe that it was not the cooling system from build.

[jake_crew]

No anodes.  The engine comprised heavy cast iron, with marine grade bronze and copper water fittings.

 

Like Fulbourne, it has a mudbox on the inlet.

[Tony Brooks]

I think the point is these old trad engines are basically all cast iron and copper alloys where as more modern engines may be casts steel with loads of aluminium alloy parts. Cast iron is pretty good at resisting rust. Some aluminium alloys happily corrode when close to other metals so an anode is used to protect them.

[Onewheeler]

Our DAF575 (61 years old of which at least 35 in the boat) is raw water cooled. The path is mud box --> pump --> engine --> exhaust manifold --> (side run to calorifier) --> oil cooler --> water-cooled exhaust (or something like that, I can't remember the exact sequence). I've no idea if there are anodes or where to look.

Edited June 4, 2020 by Onewheeler
Got it wrong!

[BEngo]

2 hours ago, Tony Brooks said:

I think the point is these old trad engines are basically all cast iron and copper alloys where as more modern engines may be casts steel with loads of aluminium alloy parts. Cast iron is pretty good at resisting rust. Some aluminium alloys happily corrode when close to other metals so an anode is used to protect them.

Cast iron may not apparently go rusty, though if you asked anyone with a rust wedged cylinder about that they might not agree, but what it does do is slowly "dissolve" if continuously in sea water, leaving the black carbon part of the matrix behind. The extent is clearly visible if the part is cut across the boundary between the good and the iron depleted areas.

  The carbon has little or no strength, so eventually there is a mechanical failure.

Anodes can slow the leaching process.

 

N

[Tony Brooks]

17 minutes ago, BEngo said:

Cast iron may not apparently go rusty, though if you asked anyone with a rust wedged cylinder about that they might not agree, but what it does do is slowly "dissolve" if continuously in sea water, leaving the black carbon part of the matrix behind. The extent is clearly visible if the part is cut across the boundary between the good and the iron depleted areas.

  The carbon has little or no strength, so eventually there is a mechanical failure.

Anodes can slow the leaching process.

 

N

 

Yes, but I think steel in contact with salt water will rust/corrod at a faster rate

[Bee]

I guess a lot of outboard motors circulate raw water. Our Beta uses heat exchanger cooling and it was trouble free for years but with low water and hotter summers and incredible weed growth it can now be a problem. Thing is though that by the time the water inlet is choked the propeller is just a spinning ball of weed too so everything stops.

[Naughty Cal]

On 03/06/2020 at 21:28, Mad Harold said:

Yes.My last boat had a BMC 1500 and had that system.

Sucked canal water from under the counter,through a strainer and Vetus water filter with a Jabscoe pump,around the water jacket and spat it out at the side.

This system will usually be on older boats.Mine was built in 1978.

Not strictly true. A lot of petrol powered cruisers still use direct raw water cooling.

3 minutes ago, Bee said:

I guess a lot of outboard motors circulate raw water. Our Beta uses heat exchanger cooling and it was trouble free for years but with low water and hotter summers and incredible weed growth it can now be a problem. Thing is though that by the time the water inlet is choked the propeller is just a spinning ball of weed too so everything stops.

And in board petrol engines as well.

 

Our Volvo diesel has indirect raw water cooling which we much prefer.

[Ex Brummie]

I have indirect raw water cooling on a Perkins 4108M. There are occasions when it is niggly with weed blocked filters, but have never had a problem with overheating on river work against strong currents. I know of three people who have had problems after engine changes, where skin tanks have not been able to cope with new cooling requirements, and another friend who had an indirect raw water cooled BMC replaced with a Beta 43 skin tank cooled unit. The additional cost more than doubled the cost of the replacement engine.

[Tony Brooks]

1 minute ago, Ex Brummie said:

I have indirect raw water cooling on a Perkins 4108M. There are occasions when it is niggly with weed blocked filters, but have never had a problem with overheating on river work against strong currents. I know of three people who have had problems after engine changes, where skin tanks have not been able to cope with new cooling requirements, and another friend who had an indirect raw water cooled BMC replaced with a Beta 43 skin tank cooled unit. The additional cost more than doubled the cost of the replacement engine.

Those three people had problems that were nothing to do with the type of cooling system but everything to do with hull builders or owners fitting a new engine who don't know or ignore the engine manufacturer's requirements for skin tank size.  We never had an overheating problem on out indirect cooled BMCs except when  customers kept on  driving with a bocked raw water inlet and the problems that caused.

 

I have no idea why the work required to increase a skin tank system's ability to handle the extra 10hp should cost as much as a new engine unless the yard cut out the old tank and welded in a new one. There are at least two other ways of improving things that are well proven over time. Those are a new larger skin tank or an extra one on the other side welded to the outside of the swim or pipes on the outside of the swim. Some yards simply weld a plate between the engine beds to make a horizontal skin tank but I don't like that method.