Heat Exchanger backflush. W50

Down2TheC · **Posted:** 21 Jun 2009 19:42

We chewed up several impellers before we learned not to run them until the water stops flowing. Now we check every year and replace every other. But for the past two years we've had sketchy cooling. We've been running hotter than normal and the tailpipe flow just didn't seem to be all there.

Rather than breaking everything apart, I wanted to try the simple approach first... and I think it worked!

The setup...

The results... 19 in tact impeller vanes and lots of little chunks.

Hopefully we've now payed for the sins of the past and will never need that process again. But if you find your cooling flow stops, this is a good quick first step.

carl s · **Joined:** 31 Dec 2006 13:33 **Posts:** 90

Great idea! I know my system is loaded with old chunks. I have had to replace my impellor anually. I think on shutdown there is some backflow to the pump and and an old chunk is taking out my impellors. Thanks, Carl

Tortuga's Lie · **Joined:** 27 Oct 2006 10:32 **Posts:** 827

So the moral of the story is that when you replace your impeller and there are pieces missing....go look for them???

Velera · **Joined:** 29 Dec 2006 09:38 **Posts:** 656

Need to find every one of them.

This should go in the technical file.

I had my boat more than five years before I figured out how to do this.

NewDay#16 · **Joined:** 12 Oct 2007 11:01 **Posts:** 35

Yes, this should go in the Technical file. Oh, and please include how to backflush the W40 as well. Plenty of them out there and all need cleaning.

Down2TheC · **Posted:** 14 Jul 2009 13:09

Assuming the W40 has an oil cooler, it's the same process. But first one to try should take pics.
I should note, that the alternative to this is to pop the cap off the end of the exchanger and go fishing. But this addresses things that have made it past the end, into the tubing.

I should be able to tell you the results in a week or so. I'm hoping for a drastic change in heat retention, and a full flow out the tailpipe!
Tartan

NewDay#16 · **Joined:** 12 Oct 2007 11:01 **Posts:** 35

I am missing an important piece; exactly what/where is the "anti-siphon inlet" hose connection? Is this actually the raw water connection to the exhaust elbow?

Velera · **Joined:** 29 Dec 2006 09:38 **Posts:** 656

Yes, Jharvey, that is right where the anti siphon (you should have one) loop injects. The engine block is below the waterline.

Also, I found that the oil cooler needs flushing and cleaning even more than the heat exchanger. I had some cooling problems (not enough water, hotter temps and blowing caps off the heat exchanger) that finally traced to an oil cooler with too much salt collected. I am guessing that you guys who live in climates where you flush your engines and store your boats on shore each season, have fewer problems than I did in San Francisco.

Down2TheC · **Posted:** 16 Jul 2009 00:01

At least on the W50, the oil cooler's connected to the anti-siphon valve. I used that hose. So the backflow goes hose, oil cooler, hose, heat exchanger, hose. Everyone gets a flush.

The anti-siphon is the valve hanging on the bulkhead. Mine needed to come down for a cleanup anyway (28 yrs and it started dripping water on the engine when it ran). But really that's just the easiest hose to get to. The one between the exchanger and the oil cooler is short and would be impossible to get off.

DAEDALUSCAN · **Joined:** 09 Dec 2007 21:03 **Posts:** 114

Down2TheC wrote:

At least on the W50, the oil cooler's connected to the anti-siphon valve. I used that hose. So the backflow goes hose, oil cooler, hose, heat exchanger, hose. Everyone gets a flush.

The anti-siphon is the valve hanging on the bulkhead. Mine needed to come down for a cleanup anyway (28 yrs and it started dripping water on the engine when it ran). But really that's just the easiest hose to get to. The one between the exchanger and the oil cooler is short and would be impossible to get off.

Actually the short hose is easy to get off as the oil cooler is mounted with a hose clamp, and once you loosen that it can move aft off the short hose. Just have to be lucky that the hose clamp on the forward/heat exchanger end is orientated in such a way that you can get to it.

Tartan37.com

Heat Exchanger backflush. W50

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