Replace Yanmar with what?

[dgadee]

I will probably replace a Yanmar 3gm30F. Ideally keeping the same shaft and folding prop. Anyone done this and what did you replace with? Yanmar again or alternative?

 

[sarabande]

There are few compelling reasons for not replacing like with like, unless you want to reduce weight or change the shaft horse power. Yanmar seem to have got the engine sorted, and spares are not horrendously expensive, as are green engines.


EDIT

Just realised it is not a 'current' engine, sorry.

The present range of comparable new ones is

3YM20 15kW
3YM30AE 21 kW
3JH5E 29kW


but there's almost certainly an engineering shop that does fully reconditioned ones..

 

[Fr J Hackett]

There are few compelling reasons for not replacing like with like, unless you want to reduce weight or change the shaft horse power. Yanmar seem to have got the engine sorted, and spares are not horrendously expensive, as are green engines.


EDIT

Just realised it is not a 'current' engine, sorry.

The present range of comparable new ones is

3YM20 15kW
3YM30AE 21 kW
3JH5E 29kW


but there's almost certainly an engineering shop that does fully reconditioned ones..

I replaced a 3gm30f with a 3ym30ae When you do you might as well replace shaft unless it's pristine, cutlass bearing because it's cheap and easy to do with engine and shaft out and certainly new mounts. I also took the opportunity to put in a flexible drive coupling which made alignment less critical and easier.

 

[Sybarite]

Many peoplke seem tu use Yanmars as replacements and so I would thought that it would be a good idea to keep the same mark. It is or it used to be the largest selling marine diesel in the world for pleasure sailing.

 

[dgadee]

I also took the opportunity to put in a flexible drive coupling which made alignment less critical and easier.

What type did you use? I was wondering about the Aquadrive but the price seems high just to reduce the time spent in alignment.

 

[Fr J Hackett]

What type did you use? I was wondering about the Aquadrive but the price seems high just to reduce the time spent in alignment.

Yes I used Aquadrive, the whole thing was part of a major refit, even now I wouldn't like to total up the cost

 

[charles_reed]

I will probably replace a Yanmar 3gm30F. Ideally keeping the same shaft and folding prop. Anyone done this and what did you replace with? Yanmar again or alternative?

I replaced my 2GM20 with a 3YM20. Allegedly interchangeable in size, in fact rather larger.
An outstanding engine, after 3000 hrs, I've never regretted the change.
However the 3YM20 is considerably more powerful then the 2GM - 23 cf 18 bhp continuous rating but infinitely more economic - 1.5 litres/hr on average.
The 3YM30 is not quite as big an improvement over the 3GM30.
The Yanmars are designed as marine engines - all their direct competitors are marinised versions of industrial diesels - the base engines are all thoroughly sound but the marinisation can vary in effectiveness.
The only stricture I'd level at the Yanmars is that the Hitachi alternators are undercooled, underpowered and melt under boat power demands for Med liveaboards.
From my experience I'd definitely suggest re-engining with another Yanmar, though there are many other cheaper alternatives.

 

[RichardS]

I replaced my 2GM20 with a 3YM20. Allegedly interchangeable in size, in fact rather larger.
An outstanding engine, after 3000 hrs, I've never regretted the change.
However the 3YM20 is considerably more powerful then the 2GM - 23 cf 18 bhp continuous rating but infinitely more economic - 1.5 litres/hr on average.
The 3YM30 is not quite as big an improvement over the 3GM30.
The Yanmars are designed as marine engines - all their direct competitors are marinised versions of industrial diesels - the base engines are all thoroughly sound but the marinisation can vary in effectiveness.
The only stricture I'd level at the Yanmars is that the Hitachi alternators are undercooled, underpowered and melt under boat power demands for Med liveaboards.
From my experience I'd definitely suggest re-engining with another Yanmar, though there are many other cheaper alternatives.

My 3YM30s both have 80A alternators factory fitted which seem to be powerful enough. I removed the front plastic moulding as soon as I got the the boat to improve the airflow through the alternator.

Richard

 

[Aurai]

Hi

As an alternative, have a look at Thorneycroft. I was impressed at their assistance and help, though actually went for a like for like Yanmar!

 

[Tranona]

Any of the mainstream brands would be a suitable replacement. Nanni/Beta are generally lower price than Yanmar or Volvo, but if your current engine is still functioning (why do you think it needs replacing?) you would probably get a good part exchange deal from a Yanmar dealer.

If you want to use the same propeller make sure you new engine has the same hp and the shaft speed (max revs/reduction ratio) is the same. Any significant deviation of either will probably mean a new set of blades with a different pitch.

 

[dgadee]

.. but if your current engine is still functioning (why do you think it needs replacing?) you would probably get a good part exchange deal from a Yanmar dealer.

I know I could have it stripped down and rebuilt relatively cheaply (my car mechanic did it with his own yanmar and is willing to do the work for me) but because it is getting on and I plan to take the boat some way from home. I intend to keep this boat (not seen anything I like better) so swallow the cost now and get the benefit of a new engine. My attitude would be different if I was thinking more short term/local sailing.

Local dealer isn't interested in taking older engines (boat is in NI) so I'll put it up on Apollo Duck. I am sure someone able to do the work will get a good project and a good engine.