Sea Water in Engine

[Pete]

I went to start my engine after an 8hr trip in following seas only to find that the cyclinders were full of salt water. I have a flapper valve on the stern. Holding the compression release and cranking the engine pumped out the water and it started. Two questions: How could the water get in there past the flapper valve and the loop, and could I have any perminant damage?

 

[Brad]

Raw water

This happened to me one time as well. I was not in a following sea. I had left the intake open, then something got by the inpellor an stuck in the raw water valve under the sink. I cleared the valve and drilled it bigger. Did not do damage to the engine. I now close the intake off, rev the engine to push out the raw water from the exaust and then shut it down. Always close your instake when you shut you engine down.... saves a lot of probs.

 

[Dwight Miller]

Anti-syphon valve

Most Catalina 30s (including mine) have an anti-syphon valve connected to the water cooled muffler. Its purpose is to prevent water from syphoning thru the raw water intake and through the engine and on into the muffler when the boat is under sail and the engine is shutdown. If this anti-syphon valve becomes clogged, this syphoning effect can take happen while you're sailing regardless of following sea or otherwise. When it does, the muffler can fill with water. Since the exhaust ports from the engine to the muffler are at a lower elevation than the exhaust line leaving the muffler and exiting the boat, the water in the muffler will back into the engine. The solution is to keep the anti-syphon valve clear or close the raw water intake through hull valve when sailing. The greatest danger with water in the engine cylinders has to do with the fact that water is not a compressible fluid. If you get water in the cylinders and then crank the engine, or perhaps fire the engine because water is not in all cylinders, the water does not compress the way fuel does and as the engine turns over, really bad things occur. Broken pistons, bent connecting rods, and broken valves are not uncommon. As long as this didn't occur, your next biggest problem with water in the engine is that it displaces and thins the oil. As you are probably aware, water will not lubricate the engine and even a small amount of water in the oil with the engine running will destroy the crankshaft and connecting rod bearings in short order. I would certainly change the oil before starting the engine again. After you change the oil, you should only run it for a few minutes (maybe five minutes or so). Then, pull the oil dipstick out. If you see any caramel colored or frothy material on the dipstick, you didn't get all the oil out. Change the oil again (and even again if necessary) until all you see on the dipstick is normally colored oil.From your description it sounds to me as if you didn't do any serious damage to the engine. Good luck.