I replace my impeller annually. That probably is excessive but I’d rather do it at the dock than underway while also fishing out broken vanes.
Jim Cosgrove
FATE 30U #343
Galesville MD
These heat exchangers are pretty amazing and forgiving pieces of engineering. I'm impressed that your engine could still function with that much blockage. When I took my end cap off I found two broken off zincs in the bottom and it was still putting through lots of water.
Paul M
NS30U #211, Sandpiper
Cowichan Bay B.C.
I also found a bunch of zinc bits laying around in the other end of the exchanger.
When I first bought the boat I replaced the zinc and impeller. I don’t use the engine for a lot of hours so I replace mine every third spring. Even after three years I have never seen any sign of cracking in the rubber.
Whenever I run the motor there is always a water flow from the exhaust and the engine has never shown the slightest hint of moving above 180F - even on the hottest summer days. I never had any reason to suspect a problem with the heat exchanger. I just opened it as a “learning experience” since I happened to have it at home and could work at it easily.
There must be a lot of access capacity built into the system. A comforting thought.
I only fund 6 rubber vanes in my heat exchanger this time.
First time I opened it was 10 years ago and there were about the same number of vanes that time. So I have only myself to blame here.
The first time I took it apart was because the end gaskets were leaking. I made new ones out of a sheet of rubber gasket material seen in this photo and they didn’t leak. I replaced one this year because water got between the end plate and the rubber through one of the bolt holes I guess and it blewup like a balloon.
No compound or sealant but I sanded the end plates and the heat exchanger ends nice and smooth. It looks like at the factory they sort of flattened the end of the heat exchanger with a belt sander , see photo below, but it is nowhere near flat - a good seal here relies heavily on the rubber gasket. I can see why someone used a sealant because these gaps are rather large.
Tom
26C #28 W13 who has no excuse for not checking and changing impellers because they are so easy to get at on a W13.
Penetang
Well; this is the gift that just keeps on giving. Just got a call from the machine shop that is working on my exhaust manifold assembly, and they say that there is a crack in the exhaust elbow. They aren’t sure if they can weld it without destroying the elbow and have suggested that they simply make up a new one (see the attached photo).
Does anyone out there in the great hive mind have a reason why I shouldn’t just go ahead with all new parts? I’m sure I could order a new elbow from Westerbeke for significant $s, but if I go with the shop replacement it will be ready tomorrow and I can get on with the business of putting the engine back together and enjoying some actual sailing.
As always; Thank You for advise rendered.
Get the locally available one. Exhaust elbows aren’t rocket science. I have made several that lasted years in 12 hr/day service. Worst case scenario is they don’t get a great injection angle and it only lasts a couple of years. By then your Westy one will have arrived.
Paul M
NS30U #211, Sandpiper
Cowichan Bay B.C.
Sorry, I didn’t see the photo. That will work but better would be a schedule 80 elbow with the water injection drilled and tapped into it at an angle that is aimed more down in the direction of exhaust flow. Shooting in square as in the photo will fail sooner.
OK but not exactly like in the photo. Water has to be injected down towards the muffler and at no time should any water have a chance to go back towards the engine like in the photo. The elbow part is cast like that for a reason.
Tom
What I was told when I built my replacement mixing elbow was that the ideal is for the water not only to be injected down towards the muffler, but also as parallel as possible to the downward pipe.
The reason for downward is that backflow is very bad. The claim for parallel to the downpipe was that, since the cooling is done with raw water, minimizing the amount of highly heated saltwater hitting the pipe sides would make it last longer. (Obviously, this is not relevant for fresh water boats.)
Since I’ve built mine but not installed it yet, this is all untested theory. I’m offering it for what it’s worth, and more knowledgeable folks may want to advise pro or con.
– Bob
Solar Wind
Nonsuch 26C #143
I would definitely go with all new and agree with Bob about the angle.
Joe Valinoti
S/V iL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
Angle is important. It doesn’t hurt to go to Schedule 80 for the elbow either but however you do it think about adding some (cheap) flex in the system to take the weight and strain off the (expensive) cast aluminium manifold.
Interesting mine has a caps with a central bolt. The cap has a raised ridge around the outside. The bolt has an O-ring seal. I did get it cleaned by Cat when I bought the boat and they discovered a crack in one of the end caps.
I see there is a by pass on the end. I have the same arrangement. What's the downside to removing that fixture?
I’m not sure which picture you are referring to but if you mean this one. The hose indicated is for attachment of a heater or hot water tank coil.
Here is a photo of mine. Note the two hoses that feed my engine heated water system.
Joe Valinoti
S/V iL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
[details="(attachments)"]
[/details]Nice clean engine room Joe. What is the spring clip red wire for?
Tim in STL
White O’morn NS26U
Harbor Point Yacht Club
West Alton, MO
That was part of the old system of pumping out the crankcase. I now have a mounted switch.
Joe
Sorry to be off topic but Joe, can you tell me what kind of pump you are using. I have been using a Pela Extractor vacuum system. It works well but can get messy.
Paul M
NS30U #211, Sandpiper
Cowichan Bay B.C.
Paul: Since the thread of emails are not shown, I’m confused about what fluid we are talking about.
Joe Valinoti
S/V iL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
Crankcase oil. Thanks Joe.