Re engine a 30ft sailing boat

[Refueler]

You want the freshwater cooled not raw water cooled one of course . Which is it ?

??
My 4-99 was indirect cooling via Heat Exchanger .. which fell apart inside .....

The replacement 4-107 was put in without Heat Exchanger and reverted to direst SW cooling. The only item to be aware of - with direct SW cooling is to run engine COOLER than Indirect - to avoid depositing salts etc. in the water channels of the engine.
In the 16 odd yrs its been in my boat (it was 2nd hand when fitted) .. I have never gad to clean waterways ... all I do is flush through with Anti-freeze at end of year ... after closing of water intake.

 

[AntarcticPilot]

??
My 4-99 was indirect cooling via Heat Exchanger .. which fell apart inside .....

The replacement 4-107 was put in without Heat Exchanger and reverted to direst SW cooling. The only item to be aware of - with direct SW cooling is to run engine COOLER than Indirect - to avoid depositing salts etc. in the water channels of the engine.
In the 16 odd yrs its been in my boat (it was 2nd hand when fitted) .. I have never gad to clean waterways ... all I do is flush through with Anti-freeze at end of year ... after closing of water intake.

I too can't see understand why people want indirect cooling. If you look through these fora, you'll see that a substantial proportion of the engine problems people ask for advice about are related to indirect cooling. My Volvo 2003 is 34 years old, and runs perfectly well. It is direct cooling; the 200x range were designed for direct cooling, so there's anode protection and plenty of metal where it might corrode. Of course, if the engine is a conversion from an automotive base engine, then indirect cooling might make sense. But I'd rate a direct cooling engine designed for marine use higher than an indirectly cooled engine that was originally designed for other purposes.

 

[Tranona]

I too can't see understand why people want indirect cooling. If you look through these fora, you'll see that a substantial proportion of the engine problems people ask for advice about are related to indirect cooling. My Volvo 2003 is 34 years old, and runs perfectly well. It is direct cooling; the 200x range were designed for direct cooling, so there's anode protection and plenty of metal where it might corrode. Of course, if the engine is a conversion from an automotive base engine, then indirect cooling might make sense. But I'd rate a direct cooling engine designed for marine use higher than an indirectly cooled engine that was originally designed for other purposes.

You don't have a choice now as don't think any marine engines are made now with direct cooling except the Yanmar 1GM. They are almost all based on industrial or, in larger sizes automotive base engines partly because volumes are low and partly because it would be difficult to meet emissions standards with the type of engine you have. While you seem happy with yours, would suggest there are just as many issues raised here about cooling system problems with direct cooling considering how few there are still around. Of course this may be due to age and neglect as much as a fundamental flaw.

 

[Buck Turgidson]

1996!
I have a 2qm15. They were discontinued in 1980. It doesn't miss a beat.

 

[Poignard]

Yeah, like wot I said! Although it is possible that one engine maker, 30 years ago, was making longer-lived engines than the others. Not necessarily Yanmar; I think Bukh have the best rep in that regard.

My raw water cooled BUKH DV10 was installed in1982.

When I bought my boat in 1997 the BUKH was in running order but burning oil, and sometimes it was difficult to start.

I overhauled it myself the following year, fitting new liner, piston, valves, valve guides, main and big-end bearings, etc., and I had the injection pump and injector serviced by a Bosch specialist. I think I spent about £1,500.00 on it.

It still starts easily, doesn't burn oil. There's not reason for me to think of replacing it.

BUT, when I come to sell the boat, potential buyers will have a good bargaining ploy, and expect allowance to be made for the cost of installing a new engine. Not because it needs one but because it might.

Nothing I can do about that. I would do the same in their place.

 

[jwilson]

We sold a boat a few years ago with a Sabb (different Norwegian company from from Saab cars) diesel engine that was well over 60 years old, and still running perfectly.... The flywheel alone probably weighed more than a complete new engine now.

 

[Blueboatman]

We sold a boat a few years ago with a Sabb (different Norwegian company from from Saab cars) diesel engine that was well over 60 years old, and still running perfectly.... The flywheel alone probably weighed more than a complete new engine now.

I had one my first diesel . Wonderful and so simple . I am not sure there were any expensive service parts , just change oil and a squirt of grease to the cylinder head parts ??

 

[LittleSister]

You don't have a choice now as don't think any marine engines are made now with direct cooling except the Yanmar 1GM.

I believe Bukh's DV series are still available with direct cooling, though the indirect cooling versions seem to be the standard model nowadays, presumably as they are now typically fitted new only to lifeboats (rather than yachts) as original equipment. Originally it was the reverse - direct cooling as standard, indirect cooling an optional extra.

According to Bukh indirect cooling is advantageous if you're doing more than 500 engine hours per annum. (Or need to meet lifeboat standards!)

 

[Poignard]

I believe Bukh's DV series are still available with direct cooling, though the indirect cooling versions seem to be the standard model nowadays, presumably as they are now typically fitted new only to lifeboats (rather than yachts) as original equipment. Originally it was the reverse - direct cooling as standard, indirect cooling an optional extra.

According to Bukh indirect cooling is advantageous if you're doing more than 500 engine hours per annum. (Or need to meet lifeboat standards!)

Indirect cooled engines are necessary in ships' lifeboats so that the engines can be run up when the lifeboat is not in the water

 

[jamie N]

Indirect cooling is 'better'. To convert from direct to indirect is a very easy and simple process, once one can appreciate that the engine manufacturer has made the engine in a manner that suits them, and isn't neccessarily the best way for the engine, it's a doddle to do, cheap and reliable.

 

[V1701]

If it's an older boat that was reengined in 1996 that would be considered a major advantage over the same boat on it's original engine. If it's the original engine on a 1996 boat you shouldn't be surprised, many (most?) 1996 boats will still be on their original engine. As others have said, do as much as you can to establish it's condition, hours run, service history, etc. It does not need replacing just because it's a 1996 engine, neither would it be an engine to particularly avoid...

 

[AntarcticPilot]

You don't have a choice now as don't think any marine engines are made now with direct cooling except the Yanmar 1GM. They are almost all based on industrial or, in larger sizes automotive base engines partly because volumes are low and partly because it would be difficult to meet emissions standards with the type of engine you have. While you seem happy with yours, would suggest there are just as many issues raised here about cooling system problems with direct cooling considering how few there are still around. Of course this may be due to age and neglect as much as a fundamental flaw.

I understand, but it always seems to me that indirect cooling is just another thing to go wrong, especially given the usual mixtures of metals in things like heat exchangers. However, as you say it seems to be a necessary evil! I suppose keel cooling would be a useful halfway house, but few boats are built with provision for it.

As far as I'm concerned, the maxims "Keep things simple" and "If it ain't broke don't fix it" apply - direct cooling is simple and doesn't introduce new parts to go wrong and in general, indirect cooling is a solution looking for a problem; if the problem exists then surely better to fix the underlying problem that indirect cooling is a solution to! However, given that new engines are unlikely to be made for marine use primarily, I guess that we have to accept it.

 

[Gixer]

What’s the classic saying?
‘Even half the price of a new engine can buy a lot of spares.’

 

[Refueler]

Indirect cooled engines are necessary in ships' lifeboats so that the engines can be run up when the lifeboat is not in the water

The L/Boat engines I used to run up once a month as 3/0 with the 4/E were NEVER indirect cooled ..... that was in open and closed L/boats .... I accept that maybe after 1989 when I came ashore - they may have changed.
The engines were only started - then shut down ... not even enough time to get anything hot.

 

[simonfraser]

are yacht inboard diesels not as stressed out as mobo inboards and as a result dont need indirect cooling ?

 

[Refueler]

Service History on a boat engine ????

Forgive me for smiling at that ............ c'mon guys and gals ............. how many actually get a dealer or mechanic to service their boat engine AND stamp / sign a record book ??????
Its not a car .... its a boat engine !

To OP ..... stop worrying about it ... if you like the boat - go and see it. Get the engine started and see what its like ... nicely painted or showing its age cosmetically is NO INDICATION of its real condition ....

 

[Buck Turgidson]

Service History on a boat engine ????

Forgive me for smiling at that ............ c'mon guys and gals ............. how many actually get a dealer or mechanic to service their boat engine AND stamp / sign a record book ??????
Its not a car .... its a boat engine !

To OP ..... stop worrying about it ... if you like the boat - go and see it. Get the engine started and see what its like ... nicely painted or showing its age cosmetically is NO INDICATION of its real condition ....

Doesn't have to be serviced by an agent. The schedule is in the engine handbook and only need doing and recording for there to be a service history. Mine is recorded in the boats log book.

 

[Refueler]

are yacht inboard diesels not as stressed out as mobo inboards and as a result dont need indirect cooling ?

Given that most sail yachts actually have engines in the lower power range for boat size / weight .... the only saving grace is that they are used less.
Indirect or direct is not a matter to really be of concern in this. There's a lot of rubbish talked about it.

 

[Refueler]

Doesn't have to be serviced by an agent. The schedule is in the engine handbook and only need doing and recording for there to be a service history. Mine is recorded in the boats log book.

Good for you ... I reckon I can say and not be wrong - that more people do not record what they do for their engines. Particularly as the boat / engine gets older. MoBo people may though as it is their main propulsion .....

 

[Tranona]

are yacht inboard diesels not as stressed out as mobo inboards and as a result dont need indirect cooling ?

Nothing really to do with the amount of power or stress, but primarily because the engines are based on industrial engines that are freshwater cooled and do not react kindly to seawater nor running at lower temperatures as traditional seawater cooled engines do. The reason for running cooler is to minimise the impact of saltwater on the water passages reducing salt deposits that eventually block the waterways. Using freshwater based coolant allows the engine to run hotter improving efficiency and helping control emissions. It also has the side benefit of making it easier to use the surplus heat for domestic water through a calorifier. Downside is the need for a second water pump and a heat exchanger to cool the freshwater using seawater. This shifts the potential corrosion problems from the engine to the HE which is the biggest cause of problems. No different from MOBO engines where the engines themselves rarely give problems but the marinising bits do. On the other hand most MOBO petrol engines are seawater cooled and tend to have short lives because of the effects of saltwater on their cooling systems.