H34 (westerbeke) cooling water flow

[lnikl]

I have a 1983 Hunter 34, early production run with a Westerbeke. I am getting steam in my exhaust. I replaced the impeller less than one year ago and today pulled a small piece of impeller out of the pump housing outlet. Still, the flow seems to be not as much as it I think it should be.
I checked the flow output from the system by connecting a hose (reduced from 3/4" to 1/2") and running it up to the cockpit drain. I checked output from the pump and again in the outlet from the heat exchanger.
I would be interested in your views whether or not there is enough pump output. Video link here.
I took it for a spin today at wide open throttle for a good half hour and the temperature stayed ok but plenty of steam.

 

[Ralph Johnstone]

First question would be, what is the temperature of the water coming out of the exhaust while under way (under load) ?

 

[Terry Cox]

Just a thought, awhile ago I cleaned out the sea water strainer and put the lid back on, but when I cinched the wing nuts down apparently the lid was not sealed flat. After the engine warmed up steam was coming out the exhaust but the temperature was normal. That had never happened before.

After re-setting the lid and getting a good tight seal the steam stopped. The sea water pump was bringing in just enough water to cool the engine, but it was also sucking air by the lid seal thus causing the steam.

 

[lnikl]

Thanks Terry, I'll double check the strainer but I have fiddled with that quite a bit already.

 

[lnikl]

First question would be, what is the temperature of the water coming out of the exhaust while under way (under load) ?

I haven't measured the exhaust water temperature. Not that easy to get to but once warmed up, it does get hot enough to turn to steam.

 

[whatfiero]

Have you checked mixing elbow plenty water comming in but can't get out cause elbow clogged up with carbon and burnt salt?

 

[Ralph Johnstone]

Have you checked mixing elbow plenty water comming in but can't get out cause elbow clogged up with carbon and burnt salt?

Whatfiero beat me to the next question. Don't know if the Westerbeke mixing elbow looks like a Yanmar, but this is always a possible restriction ............................

 

[jssailem]

this is always a possible restriction ........................

That looks more like a blockage. If it was human it would be open heart surgery time.

 

[lnikl]

Thanks Whatfiero and Jsssailem. The mixing elbow is new. I have pushed a pipe cleaner through and it is completely unplugged.

 

[kloudie1]

A possible is a collapsing water intake hose.. I have seen hoses that looked fine on the outside but the interior liner was collapsing and restricting flow. Another thing might be a partially clogged external strainer.

 

[RoyS]

Flow in your video looks about right to me. Some amount of steam can be released with water in the fuel. This can cause catastrophic damage to your injector pump. Head gasket could also admit water to cylinder. Happy hunting.

 

[PGIJon]

It's not very difficult to remove the heat exchanger. I've found bits of the impeller in there. It's always worth a look to ensure that all the tubes are clear. -Jon

 

[lnikl]

Flow in your video looks about right to me. Some amount of steam can be released with water in the fuel. This can cause catastrophic damage to your injector pump. Head gasket could also admit water to cylinder. Happy hunting.

Thanks Roy. I think that the fuel is ok. There is a glass bowl on the fuel filter/separator.

 

[lnikl]

It's not very difficult to remove the heat exchanger. I've found bits of the impeller in there. It's always worth a look to ensure that all the tubes are clear. -Jon

Thanks John, I did pull the two end caps off of the heat exchanger. No impeller bits but I did find bits of the pencil zinc in there and removed them. I also checked the flow before and after the heat exchanger and there was no noticeable difference.

 

[lnikl]

A possible is a collapsing water intake hose.. I have seen hoses that looked fine on the outside but the interior liner was collapsing and restricting flow. Another thing might be a partially clogged external strainer.

Thanks Kloudie, I just had the boat out on the hard for maintenance and the intake was good and clean. I have given the hoses a squeeze and there was a bit of a crunchy sound on the one from the exchanger to the mixing elbow. I pulled it out and while there were some deposits (presumably scale), the hose was open. I cleaned it and put it back on. There are two more hoses that seem good as new but maybe I should pull them and have a peak in case there is the collapse that you mention.

 

[lnikl]

Just a thought, awhile ago I cleaned out the sea water strainer and put the lid back on, but when I cinched the wing nuts down apparently the lid was not sealed flat. After the engine warmed up steam was coming out the exhaust but the temperature was normal. That had never happened before.

After re-setting the lid and getting a good tight seal the steam stopped. The sea water pump was bringing in just enough water to cool the engine, but it was also sucking air by the lid seal thus causing the steam.

Terry,
I did notice a little bit of weaping around the seal. Apparently that strainer has an o-ring kit that is available for it. Just taking a guess but those O-rings are probably ~33 years old so I am going to give that a go.

 

[lnikl]

Apologies for the delay in posting a solution to this. As it turns out, the previous owner had used a hose that was one size too small. I got a 7/8” from a plumbing supply company in Vancouver and it is spewing luxurious amounts of water with no steam.
I suspect that as the hose warmed up (and got old), the bend in the hose started to pinch the flow. Works great now.

 

[jssailem]

Good resolution Lee. You did say it was a mature boat. Should have included the hoses in the discussion. It is one of the easier projects to address. New is good. Hope it has a wire coil running through it it helps the hose maintain shape as it gets under vacuum.

You might just give all your hoses a squeeze the next time your looking at the engine. Hoses do degrade, get soft with age. Like so many things.

 

[lnikl]

Good resolution Lee. You did say it was a mature boat. Should have included the hoses in the discussion. It is one of the easier projects to address. New is good. Hope it has a wire coil running through it it helps the hose maintain shape as it gets under vacuum.

You might just give all your hoses a squeeze the next time your looking at the engine. Hoses do degrade, get soft with age. Like so many things.

In this case, it was compounded by the fact that the hose was undersized. I have no idea how the previous owner got it attached, I tried putting the same hose on and did all manner of boat yoga but to no avail. Then I measured the hose nipple and realized the problem. No coils in the hose unfortunately. That size wasn’t available at the marine store and they swore up and down that it wasn’t made in that size. It is.

 

[Ralph Johnstone]

Good to hear after all these years @lnikl . As long as there's no sharp bends in the hose, hopefully you'll have no crimps.

7/8" ID hose does sound like a bit of an odd ball size. Did you try Martin Marine ? They're usually pretty good for odd ball stuff or they'll find it for you.

degrade, get soft with age. Like so many things.

The hell you say. Arteries get harder with age.
But yeah, the more important things get softer.