Want To Buy: Yanmar 3QM30 Housing Parts

[Toph3r]

I have a 1979 Yanmar 3QM30F (Freshwater cooled) that has developed a crack in the heat exchanger housing side-mount. It is probably a long shot, but I am hoping someone out there has a spare parts 3QM30F.


I believe the part number is 724790-44560 and have attached diagrams for reference.


Cheers!

[Toph3r]

Here are a couple more pictures of what I am looking for.

[Wotname]

Welcome aboard CF.

As this is an international forum, it might help if you let us know what country you are in.

It is likely the end plate could be welded if you can't source a replacement. Welding cast is a little more difficult but not impossible if the right techniques are used.

Worse case, a new end cap could be fabricated although unless you can do the work yourself, it could be expensive. If the general condition of the engine is good, it would be worth it. IMHO, the 3QM30 is one of the best engines Yanmar ever made even if a bit heavy!

[Toph3r]

Thanks for the input Wotname. And thanks for the reminder about location, I updated my profile with my location in the US.


I have thought about trying to get it welded, but haven't talked to any shops yet, I think a chunk of the metal would have to be removed and replaced because it is rusted/corroded in a very uneven way and water seeps through when it is running. Worse case I might slather the inside and out with JB weld and see if that holds up a couple of years.


I don't have the Fab skills to make the part myself, so I would be reliant on a shop to do so. Hoping to exhaust the reasonable efforts to purchase a replacement. The motor is still strong and good, but parts are getting very difficult to find. I am really trying to limp along for another 5 years or so before doing a repower; right now just isn't the right time to drop 15k-20k on a new motor.


There are a couple of 3QM30s in ebay that I have been eyeballing and just a source of spare parts heh.

[Wotname]

Yes, the JB Weld or Devcon route might get you out of trouble. Perhaps the outside could be bulked up with epoxy and glass??

Thinking aloud -

1. There is not a lot of heat involved, not much strength is required and no pressure so sealing the crack is the primary concern and preventing it from getting worse is the secondary concern. Keeping the seawater away from the inside surface will go a long way in preventing further corrosion. Adding epoxy and glass to the exterior would help in providing additional strength to the thinner parts.

2. Brazing it may be a better option than welding - you need a component machinist or welder to make the call.

3. Presumably the other identical end cap is in a better condition, if so, it could be used as a mold to have another one cast - perhaps in bronze. I guess that is not a cheap option but there are probably a few places near Seattle that can do this (Port Townsend??). You might end up supplying the world with replacement end caps!!!