Cheaper Yanmar Exhaust Elbows!

[Rossynant]

I would certainly stick to cast steel. I had a stainless muffler once and it corroded in a couple of years.

I had stainless muffler in my Ford, lasted 20+ years. No water-injected, granted. But stainless steel of suitable type will last long time. I would stress "suitable type alloy".
Making an injection elbow for given pattern around here would cost about 30-40 pounds. This is the real value of it. So anybody in need - go and ask local muffler shop.
Another thing - there is no need to keep to original design. Design should be made for a boat, not for an engine.

 

[Poignard]

I hope he starts making them for the BUKH DV10. I have had to replace two cast exhaust elbows in 15 years. Ruinously expensive!

 

[onesea]

If your talking Exhaust elbows, ask him hes a nice guy he might say yes!

 

[vyv_cox]

I hope he starts making them for the BUKH DV10. I have had to replace two cast exhaust elbows in 15 years. Ruinously expensive!

I believe it is possible to make up an elbow for a Bukh using cast iron plumbing fittings at very low cost. A couple of articles have detailed what is needed but I'm afraid I don't have copies or a reference.

 

[wotayottie]

The exhaust elbow on my Yanmar 1 GM 10 looked fine on the outside, but further examination showed deterioration (Leak!) on the internal tube. I was astonished at the price of a new one, and finally found a company in Northern Ireland, who cut my existing one, inserted a replacement inner tube, and welded it all back together! That was a couple of years ago, and cost me £55 altogether.

I checked the elbow this winter, inside and out, and it is as good as new'

You could always give them a ring and enquire:

Ards Stainless marine
Unit 1, Copeland Marina,
Donaghadee


Tel: 07774 977469

The person's name was Alex, and most helpful!

No association with them, except as an extremely satisfied customer.

I was told that the inner sleeve on the yanmar exhaust was some variety of nickel alloy because that is the hot metal that has sea water squirted onto it. It wont be ordninary 304 or 316 neither of which would last long in that situation.

 

[charles_reed]

I believe it is possible to make up an elbow for a Bukh using cast iron plumbing fittings at very low cost. A couple of articles have detailed what is needed but I'm afraid I don't have copies or a reference.

What ever the water-injection elbow, it will invariably be cheaper to have one made up by a local engineering shop than to buy the replacement from a distributor - bear in mind the OEM part will have to support at least 3 mark ups - that means the sale price will be about x2.5 the cost price (and that's not including the various value-addition and import taxes levied by government).

I have been in touch with Ben and he came back to me regretting that he can't help with the YM elbow which I asked him about, so I suspect he's only producing those which are in demand in the States.

 

[Appledore]

I was told that the inner sleeve on the yanmar exhaust was some variety of nickel alloy because that is the hot metal that has sea water squirted onto it. It wont be ordninary 304 or 316 neither of which would last long in that situation.

All I can say is that after 2 years the inner sleeve is still fine, with no signs of corrosion. The company that fitted it are marine engineers who deal in stainless fittings, so I assume they know what they are doing

 

[vyv_cox]

I was told that the inner sleeve on the yanmar exhaust was some variety of nickel alloy because that is the hot metal that has sea water squirted onto it. It wont be ordninary 304 or 316 neither of which would last long in that situation.

That's an interesting one that might explain the high cost. I was talking to Cspray a couple of weeks ago about crevice corrosion. They use a high nickel alloy called 904L that is apparently very resistant. It's the same stuff that Rolex use for their watch cases, as it is also resistant to allergenic problems that some people suffer with lower stainless grades. We didn't discuss costs directly but the word 'expensive' was used.

 

[Jabamusic]

As a slight aside, is the 3gm10 (Rawwater) elbow as prone to this sort of rot as all the others (ie 1 & 2 series)?

I thought I read somewhere they are different in some way?

 

[Poignard]

I believe it is possible to make up an elbow for a Bukh using cast iron plumbing fittings at very low cost. A couple of articles have detailed what is needed but I'm afraid I don't have copies or a reference.

Thanks. If I come across them I'll let you have details.

 

[Mistroma]

The DV20 elbow in my old boat cracked on way back from Holland around 1987. It took about 12 hours to close the last 6 miles to the coast under sail as it was blowing F9 according to Bridlington (offshore fortunately). I trekked around Bridlington and bought:
2 x 90 deg. cast elbows
1 x cast T-piece
1 x threaded cap with a reducer
1 x Short length of pipe

I'm a bit fuzzy about the exact details but think someone cut bits of pipe and threaded the ends. I think that one 90 deg. went on to the flange where the elbow attached to the exhaust. The water was injected through the side of the T-piece in middle of the upright section and lower 90 deg. bend connected to a stub of pipe and then the flexible exhaust hose.

So it is possible and it worked for the rest of the season and I kept it for a while as an emergency spare. Must have been a lot less efficient than the original curved elbow. However, power and fuel efficiency didn't seem to be any worse. It was fine for the 200nm trip back home and I must have done another 100nm before replacing it.

Sorry that I don't have detailed parts and schematics. I thought that this was unique and hadn't heard of others trying it.

 

[Marsupial]

I was told that the inner sleeve on the yanmar exhaust was some variety of nickel alloy because that is the hot metal that has sea water squirted onto it. It wont be ordninary 304 or 316 neither of which would last long in that situation.

316 (superaustenitic) is a high nickel content (10%) stainless steel suitable for high temperature corrosive environments like exhaust elbows - so it should be fine.

 

[charles_reed]

316 (superaustenitic) is a high nickel content (10%) stainless steel suitable for high temperature corrosive environments like exhaust elbows - so it should be fine.

Before one rushes off thinking all 316 stainless is the same look here and expose bare posterior rather less ;-)

http://www.bssa.org.uk/topics.php?article=606

 

[Marsupial]

Charles, can we at least agree that 316L is the most cost vs corrosion resistant material for use on boats, we could use duplex or special alloys but the cost is horrendous. coupled with the difficulty of knowing exactly what the machine shop actually used . . . .

 

[Zagato]

Just picked up the exhaust elbow from the Posty, came to £81 in total - quite a saving of £60 for a Yanmar one or £70 for the one I was going for ( I wonder if the guy I was going to buy off does actually make them or just orders Bens one's in and flogs them on!!) Neat welding, looks a good product.