How is the water getting into my engine?

[Grant Gordon]

I have an early 80's Universal 3 cylinder engine. Twice last year during rough offshore passages, the engine managed to back fill with water. My thought is that it is coming back through the exhaust.

At the end of the passage, when I tried to start the engine, to enter a canal in one instance and a marina in the other, it would not turn over. In both cases there was water in the cylinders.

There are no problems when sailing in calmer conditions. There are no issues operating under power. I have had the boat for 10 years and have never had a problem before this past summer.

My best guess is that the problem lies in the mixing elbow and I was about to take it off today but thought I would do a bit of research first. I scanned the forums here but have not found a similar problem being discussed.

Any thoughts?

[boatman61]

Has your exhaust pipe got a loop in it...

[travellerw]

A failed mixing elbow could cause this. If it has failed internally, then it could be siphoning water through holes between the channels. I would take it off and inspect it for sure.

Are you sure you didn't do any damage to the engine?

[irwin37]

vacuum break (anti siphon loop) clogged?

[Grant Gordon]

The exhaust hose does have a loop in it although it is fairly shallow because it is under the cockpit floor.

Thanks Travellerw. That's one vote for taking the elbow off and checking it out which is what my first thought was. I am pretty sure that the engine was not damaged. I recognized the symptom when it failed to start right away. I dealt with the problem in both cases by removing the injectors and turning the engine over by hand to blow out the water, and then with the start to get the rest. After putting it back together and bleeding the fuel system it started and ran without problem.

[a64pilot]

Only thing is mixing elbow wouldn't require rough weather to leak water into the engine.
When you had the problem, were you heeling excessively, or big following seas? If following seas maybe a flapper on the exhaust

Although inspecting the elbow is a good idea anyway


Sent from my iPad using Cruisers Sailing Forum

[Jim Cate]

As suggested above, do check your anti-siphon valve (if installed). They will often clog up and stop doing their venting job. This might go unnoticed in normal conditions and only appear when heeled a lot or pitching a lot.

And a lot less work than checking the elbow!

Cheers,

Jim

[transmitterdan]

Also check the siphon break in the raw water supply line to the mixing elbow. Sometimes t's easier to get water siphoned through that than backwards through the exhaust.

[japarker11]

Originally Posted by Grant Gordon

I have an early 80's Universal 3 cylinder engine. Twice last year during rough offshore passages, the engine managed to back fill with water. My thought is that it is coming back through the exhaust. At the end of the passage, when I tried to start the engine, to enter a canal in one instance and a marina in the other, it would not turn over. In both cases there was water in the cylinders. There are no problems when sailing in calmer conditions. There are no issues operating under power. I have had the boat for 10 years and have never had a problem before this past summer. My best guess is that the problem lies in the mixing elbow and I was about to take it off today but thought I would do a bit of research first. I scanned the forums here but have not found a similar problem being discussed. Any thoughts?

I would definitely be looking for the existence and operation of a vented loop in your raw water intake line. Read Nigel Calder's recommendations on this. We currently have a locked up genset that functioned perfectly for two years........until we did our first offshore passage that included some 5 meter swells. I always thought water in the exhaust manifold came from the exhaust side. After reading Calder, went looking for the vented loop (also required in the OEM installation manual)......nada. Normal practice is to vent it to the bilge. Calder is so paranoid about it, he recommends venting to the cockpit!

The auxiliary has one in a prominent location and did not suffer the same fate.

Sounds like you were able to clear the water before it seized.

[chala]

Originally Posted by Grant Gordon

I scanned the forums here but have not found a similar problem being discussed.

Good on you. There are many mostly hidden.

http://www.cruisersforum.com/forums/...el-138593.html

[gonesail]

some of the older boats did not have a loop in the intake water line. my 1989 did not have one. but you can always retrofit it.

[chala]

Originally Posted by japarker11

5 meter swells.

I would turn off all the valves connecting the engines to the sea.

[Schrewsburyduo]

Some backfilling can occur when starting the motor. If you turn it over a lot before it starts... The water pump keeps getting water into the exhaust system and there's no exhaust to push it out. You could then start the motor with the water seacock closed and have to remember to open it as soon as the motor has started.

I second having ways to stop ALL water from entering your boat. The water intake seacock should be closed when sailing. My boat also has a giant inline valve/seacock on the 2" exhaust exit. Thus way if I have a following sea I can simply close it. I open it when starting the motor. It's more effective than the flapper valve that may or may not work on your boar form factor. This is a simple way to fix the ongoing problem without much money but you HAVE to remember to open those two seacocks when using the motor... Otherways, boom! And I would also redo the cylinders to clear all the water from the motor.

[gjordan]

Calder is correct about venting to the cockpit, or as one of my boats was set up, it vented into the cockpit scupper, just below the cockpit sole. At start up you could look down into the drain and see little squirts of water, proving that you had water circulating. It also sounded different if the water wasnt flowing, so it was a good check. Does your exhaust go out the transom, or out the side of the boat? If it goes out the transom, you can usually raise your exhaust loop right up to the bottom of the deck. As has been stated earlier, if it was a rusted out exhaust elbow, it probably would happen under any conditions, not just rough. Check the easy stuff first (anti siphon valve). Good Luck____and I bet people get out names confused!!!______Grant Jordan.

[Grant Gordon]

Thanks for all the replies so far. A couple of people have mentioned anti-syphon valves and I am curious. In my original post I mentioned mixing elbow but what I really have attached to the exhaust manifold is a Westerbeke "exhaust elbow riser" (their name, not mine) similar to this:

Westerbeke 37403 Sailboat Supplies, Engine Parts and Boat Parts

Would something like this have a back flow preventer or anti syphon in it by default? If it does and that has failed, it is most likely where my problem is.

Cheers,

Grant