Yanmar 3ym30 hot water connections

[dgadee]

Just trying to work out how to plumb my calorifier into the new engine. I have found mention of a 'hot water kit' being needed rather than off the shelf plumbing connections. Can't see this advertised anywhere. Can this be done without a special kit?

 

[VicS]

Just trying to work out how to plumb my calorifier into the new engine. I have found mention of a 'hot water kit' being needed rather than off the shelf plumbing connections. Can't see this advertised anywhere. Can this be done without a special kit?

Deleted ... see below

 

[RichardS]

I'm sure that on my 3YM30s the spigots for the calorifier hoses are an integral part of the castings for the thermostat housing and somewhere else on the block which I can't remember.

I would have thought that those were standard castings but with the spigots blanked off if a calorifier is not fitted, and all you would have to do is remove the blanking plug.

If you do not have the the spigots anywhere you will probably have to buy them and swap over your current fittings. I can probably dig out some photos which show the spigots if you can't see any.

Richard

 

[VicS]

The inset diagrams in Fig 14 in the parts catalog show what's involved and the location of the connection points on the freshwater pump/thermostat housing.

Can apparently be done with or without a shut off cock .

https://j109.org/docs/yanmar_3ym30_parts_catalog.pdf

Looks like the lifting bracket/ fuel filter mounting also has to be changed! ........ maybe just modified.

 

[dgadee]

I can see the blanking plugs on the thermostat housing but wondered whether the 'kit' is actually required.

Just seen a pic on a Canadian site which claims to be for the 3YM30:



and have just received an email with a pic (won't upload it in case it is copyright) of the parts from Frenchmarine which look a bit more cobbled together from parts and costs £60 plus postage plus VAT. I think I will look at the thread of the blanking plugs before I spend money.

 

[GEB]

https://www.maritimepropulsion.com/files/pdf/1001374
Look at figure 19 on page 22

 

[dgadee]

https://www.maritimepropulsion.com/files/pdf/1001374
Look at figure 19 on page 22

Yes, I can see the plug locations:



but that doesn't really answer my question as to whether I can use off the shelf connectors or whether the Yanmar kit is a necessity. My query is because of a statement:

"If you want hot water from your Yanmar engine you’ll have to buy special parts again. There are two take-offs both have different threads. Why can’t Yanmar use standard BSP threads like everyone else? Needless to say, the price of these ‘special’ parts are hardly cheap and have to be ordered." at http://www.ventspleen.com/yanmar-3ym-20-long-term-review/

 

[GEB]

I pretty sure my engine has fittings (supplied with the engine) in the hoses - I don't remember buying any special fittings. I will have a look tomorrow.

 

[RichardS]

"If you want hot water from your Yanmar engine you’ll have to buy special parts again. There are two take-offs both have different threads. Why can’t Yanmar use standard BSP threads like everyone else? Needless to say, the price of these ‘special’ parts are hardly cheap and have to be ordered." at http://www.ventspleen.com/yanmar-3ym-20-long-term-review/

That's interesting. I would have assumed that the threads would be standard since other threads on the engine, like the seacocks for example, are standard. However, if they are some sort of bespoke thread then that certainly doesn't make it easy.

If you look carefully at the threads you will be able to see whether they are tapered or have an o-ring or similar. You could then measure the ID and, armed with that knowledge, perhaps get a plumbers merchant (leave a deposit) to lend you a selection of threaded barbs or similar so you can try a few.

Richard

 

[GEB]

Fittings are used but I think these were supplied blanked off when I purchased the engine (new) in 2007

 

[dgadee]

I took the plugs out today:



One is tapered, the other not. They have diferent threads. I can't find my thread gauges so not sure what these are. I will investigate further. [Edit: pretty sure the non tapered one is M16 at 1.5mm. That seems to be a common banjo joint size.]

GEB's images have a Yanmar kit (without shut-off cocks) but this did not come with my engine.

 

[RichardS]

I took the plugs out today:

View attachment 62532

One is tapered, the other not. They have diferent threads. I can't find my thread gauges so not sure what these are. I will investigate further. [Edit: pretty sure the non tapered one is M16 at 1.5mm. That seems to be a common banjo joint size.]

GEB's images have a Yanmar kit (without shut-off cocks) but this did not come with my engine.

It does indeed sound as if the non-taper is a banjo fitting and the taper is simply a tapered barb fitting. I've never looked at my factory Yanmar fittings that closely but they definitely don't have valves which would be unnecessary and just more to go wrong. I reckon if you contact someone like Hyphose, and possibly send them your fittings, they will be able to supply you with the right barbed parts, usually used for hydraulic systems, for £20-odd.

Richard