exhaust system problem

[allen]

I pressure tested the cooling jacket. No leaks. That was quite a relief as manifolds for my engine are not available. My last oil change, about 3 weeks ago, had no sign of water.

Here is my latest theory: The major water event was when the exhaust valve was stuck open. That was when I ran the engine with a stuck exhaust valve for several minutes to see if it would clear as the engine warmed up. There was water in the oil after that.

With a stuck open exhaust valve, there will be at least one cycle with the piston pulling suction on the exhaust. At the very least, that will disrupt the pressure trying to force water out of the water lift. Maybe that explains the major water event and the stuck valve is something else.

That still doesn't answer the question of why the exhaust valve stuck though. They say that is usually water leading to rust on the valve.

I still plan on upgrading to the LSS45A water lift. If that doesn't work, I will lower the high point of my exhaust.

That leads me to my initial question: Where does the exhaust hose run in the Cal boats? Specifically, where is the high point?

Allen

[rcvesselstyn]

Hi Allan, it's hard for me to say where the original exhaust lines ran. On the 28 the first thing I did was to replace the stainless steel Muffler and reroute the exhaust line from the atomic 4. That was a short 40 years ago or so. So my memory of the original line is probably not accurate. My redo of the line however was very similar to your diagram and the pictures of your boat. After the water lift Muffler up to underneath the cockpit sole
up higher in the transom behind the lazarette and then out the stern. On the 29 the boat had been repowered in 1984. The original exhaust line had been rerouted and replaced at that time. As part of our initial redo I tore it all out and ran a new exhaust line which again mimics your diagram and your boat. I put the water lift Muffler as low as I could on the hull. The exhaust line then runs at approximate berth level in the engine compartment to the bulkhead to the lazarette. From there it goes up to the level of the cockpit seats and then down to the exit in the transom. Perhaps the only difference that I can see is your line might be higher at its High Point.
Your idea of the stuck valve allowing the suction to pull the water into the cylinder sounds like it might hold water, I mean, might be a valid theory. That's great news that there is no water showing up in your oil anymore after you run it. As far as the stuck valve, back in the day we used to have problems with the oil of the time clogging up the oil channels in the block. The old oils that we used to use were not as refined as the modern oils of today and they had a lot of wax in them. But those blocked oil channels would cause sticky valves and all sorts of other problems. We used to end up putting outside Oilers on some of the engines just to save us from having to disassemble and clean them out. I can't say that this is your problem at all. Other things that come to mind are less likely but possible. you could have a bent or bulging valve stem which is usually caused by something, maybe even a hydrolock, blocking the valve from opening. The stem could bind on the valve guide and cause a sticky valve. It works out to kind of circular reasoning though, because you wouldn't have had the hydrolock if the valve hadn't stuck. Sorry to hear you're fighting this battle. I honestly can say I stopped enjoying working on engines when I was in my twenties. I try to avoid it unless there is no logical alternative.

[allen]

Thanks for the reply. One thing I have considered is making the high point lower so it is helpful to hear that is what you have.

By the way, I replaced the valve and spring in an attempt to cure this issue. If anything, it made the problem worse.

Could very well be clogged oil passages. I am changing the oil monthly to see if that helps. I am about due for the third of those monthly changes. Perhaps I should look into some engine flush product for the next oil change.

Allen