Bay horse, my 79 H33 has been out of the water, on top of a hill and 150 miles from salt water for over a year and a half. A refit which was to have taken 4 months presently extends nearly 5 times that as the projects have multiplied and this refitter's limitations have been exposed by the harsh reality of the skills required. Nonetheless, last Friday I changed the crankcase oil, a certain sign that the days of landlocked exile are nearly over. In contrast to most of the boat's systems, the engine, in great shape coming out, had only required normal maintenance, changing out filters, zincs and the like. Still, since it had been quiet for so long, I thought it prudent to fire it up. After all, I didn't want my vision of dock manager oohs and aahs over the refit transformation ruined by the humiliation of having to be hauled clear of his travel lift slip. How to run the engine out of the water was thus the question. The water intake through hull couldn't be conveniently submerged and the dry cutlass bearing clearly cautioned against any propeller shaft rotation. A workable solution was simple enough, just connect a length of suitable hose to the raw water hose disconnected at the through hull end, extend the lengthened raw water intake out of the boat and into a barrel of water kept full with a water hose. Since my piece of automotive heater hose proved too short to extend into a barrel sitting on the ground alongside the boat, a five gallon bucket sitting in the cockpit substituted as storage barrel. The cockpit drain would take care of any overflow. My pride was boundless as the long inactive Yanmar 2gm clattered into life at once and settled down immediately into a smooth 1500 rpm idle that seemed to me suitable for carrying the new oil all around the internals and guaranteeing that the next try under the dock manager's watchful eye would be similarly successful. At this point, I was interrupted before I ran the engine the 15 or 20 minutes I thought prudent so I just turned off the water hose and left the boat and setup knowing I could get back to it on Saturday. Saturday morning early I turned back on my water hose, checked my rig and hit the starter button. At first, the engine just clicked and wouldn't turn over but I thought that perhaps my batteries might be down a bit and so persisted until I did get it turning although with uncharacteristic sluggishness. Likewise out of character, it didn't crank immediately Finally catching and running at first raggedly, I settled it down into the same 1500 rpm idle expecting to finish out my self imposed 15 or 20 minutes of running and shut it down till splash day. It was not to be. Midway through the expected run, the exhaust began sending out successive large pungent puffs of white smoke. Thinking to clear out whatever was causing this, I revved it up toward 3000 rpm and then cut the throttle. The engines reaction to this was to continue creeping upward in rpm. Perturbed at this insubordination, I pulled the engine kill knob all the way out and sat now thoroughly alarmed watching the tachometer rapidly reach the 3600 red line rpm and continue on upward toward 4000, the limit of the tachometer. Several months ago, I read an article by Ben Hilke on the Sailnet site recounting his experience with a runaway diesel engine. He ended up shutting his down after badly burning himself on the hot engine by simultaneously shutting off the three air intakes to his engine using two hands and a foot. While reading the article I remember thinking that the Yanmar at least has a compression release on top of the valve cover, easy to reach without getting burned. Now as I tumbled down the companionway ladder toward the luckily open engine box, that article flashed through my mind and by the time I hit the bottom, I remembered the compression releases. Opening them both was a second's work, and a few more seconds brought the engine to a halt. My first thought was well, that's it. It's ruined and a new engine at $8000 is not going to be in the cards. Even if I agree with Toad that messing about in boats is fun, a year and a half of messing about and not sailing about is more than enough and besides, I'm definitely not getting any younger. I saw a vision of bay horse turning green with mildew as the years go along with my wife regularly pointing out the highly visible eyesore in its highly visible location every time she drove by it. Then I remembered that after all it hadn't run but a few seconds and I never saw it really peg on 4000 rpm. Maybe there's a chance. What had happened? I didn't have a clue. Pulling out the dip stick that I had used just the day before to fill the bright new oil level just exactly to the full mark showed an amazing whitish brown froth all the way up the stick to the rubber seal. Clearly the oil had water, lots of water in it. Coming back into the cockpit, I saw my ingenious cooling water apparatus and then remembered that the raw water inlet extension had still been in the bucket from the day before. There it was. With the water level so much higher than the engine and with the pipe primed and water in the bucket from the day before, the water had continued to siphon through the raw water extension pipe all night long. A little study of the Yanmar manual filled in some blanks. The design of the impeller pump, though essentially a displacement pump, has designed in side clearance (plus extra clearance from wear) between housing and impeller enough, as I had just demonstrated for a small continuously applied hydraulic head to push an appreciable volume of water through it over time even though the impeller does not turn. From the pump, the thermostat provides a splitter type arrangement, taking the water output from the pump and sending it through the engine or bypassing directly to the mixing elbow discharge. Thus, even after the thermostat closed with the cooling engine, the water passage direct to the mixing elbow was still open. From the mixing elbow, the siphoning water ran down the exhaust pipe and then backed up equally on both sides of the muffler until on the engine side, water backed up the exhaust manifold past the mixing elbow entrance, into the combustion chamber through an open exhaust valve, and then leaked downward over time past the piston rings to the crankcase. The stage is complete. Now when I was able to get the dependable old engine cranked in spite of the abuse of water that it had been subjected to overnight, the rotating piston rod ends and crankshaft turning beneath the mixed oil and water in the crankcase soon made a frothing milkshake out of it all, the mixtue began to get past the oil control rings into the combustion chamber as the engine ran and behold, an engine that runs on its own crankcase oil and is not subject to throttle or kill button. The rest turned out amazingly well. I went through 3 different oil changes and an oil filter change, running the engine very gently on each change for perhaps 20 or 30 minutes each until all of the milky color was gone. (Thank you John Stewart for giving me the vacuum oil changer to use which made all of this oil changing on a hot engine fairly easy) Checking the compression on the engine with a hand crank shows no perceptible loss of compression and the engine still cranks and runs as before. You can be sure that in subsequent running yesterday, I made very very sure to take the raw water pipe out of the bucket when the engine wasn't running. I think this time I have missed the bullet but am posting this now so maybe somebody else won't repeat this. I have also posted a photo of the star crossed setup.
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My Goodness, Terry!
Sorry about the bad luck, but delighted that the engine has chosen to continue living! Interestingly, the only GREAT diesel mechanic I have had the pleasure to work with (and it was a pleasure), said that more engines die from water coming back in by the way you descrbed, than from any other cause. Of course, they are usually in the water, but he pointed out how easy it is for water to get past the impeller, and fill the exhaust. And, if the engine is below the water line, as many are, you have only your anti-siphon valve to save you. And, we all know that they can fail! I wonder what the average time since the average HOW participant has checked his anti-siphon valve would be??? My mechanic also noted that an engine position relative to the water line can change when heeled. He felt, very strongly, that the intake seacock should always be shut when the engine was not running, even if it were underway, under sail. Which, of course, would mean you could get rid of the anti-siphon valve, etc. etc. etc. etc.! If you are six feet tall, the engine intake thru - hull is just reachable through the engine compartment door, and if you hang the key on the valve handle, or some other special place, you won't forget to open it. Casual Water actually has a sea-cock in her exhaust, as well, but that is another story. I am glad that Bay Horse's "swim" was in fresh water and not salt. Having salt water in there all night could have been very ugly. Thank goodness it all came out OK. Some unrelated good news....yesterday,I finally got a digital camera, so now I can set about photographing some of my little projects!
Sorry about the bad luck, but delighted that the engine has chosen to continue living! Interestingly, the only GREAT diesel mechanic I have had the pleasure to work with (and it was a pleasure), said that more engines die from water coming back in by the way you descrbed, than from any other cause. Of course, they are usually in the water, but he pointed out how easy it is for water to get past the impeller, and fill the exhaust. And, if the engine is below the water line, as many are, you have only your anti-siphon valve to save you. And, we all know that they can fail! I wonder what the average time since the average HOW participant has checked his anti-siphon valve would be??? My mechanic also noted that an engine position relative to the water line can change when heeled. He felt, very strongly, that the intake seacock should always be shut when the engine was not running, even if it were underway, under sail. Which, of course, would mean you could get rid of the anti-siphon valve, etc. etc. etc. etc.! If you are six feet tall, the engine intake thru - hull is just reachable through the engine compartment door, and if you hang the key on the valve handle, or some other special place, you won't forget to open it. Casual Water actually has a sea-cock in her exhaust, as well, but that is another story. I am glad that Bay Horse's "swim" was in fresh water and not salt. Having salt water in there all night could have been very ugly. Thank goodness it all came out OK. Some unrelated good news....yesterday,I finally got a digital camera, so now I can set about photographing some of my little projects!
Thanks for the honest report...
Terry, Glad to hear you got a handle on the situation and kept your engine running. Being new to diesel engines I read as much as I could aout the 5411 that came with my C30. I kept coming across statements having to do with sea water being sucked into the engine after it was shut down if the anti-siphon valve should fail to work. I also read statements having to do with cranking the engine too long trying to start it and drawing water into the cylinders that way. From the start I have always closed the intake seacock after shutting the engine down, even while sailing. My wife and I are always asking each oither if it is open or closed, just in case one of us forgot. By the way, the owners manual on this Universal engine even states that the fuel valve should be closed too, keeping fuel from being sucked into the engine while it is off. Although I can't figure how that would happen we generally close it, too. Chris
Terry, Glad to hear you got a handle on the situation and kept your engine running. Being new to diesel engines I read as much as I could aout the 5411 that came with my C30. I kept coming across statements having to do with sea water being sucked into the engine after it was shut down if the anti-siphon valve should fail to work. I also read statements having to do with cranking the engine too long trying to start it and drawing water into the cylinders that way. From the start I have always closed the intake seacock after shutting the engine down, even while sailing. My wife and I are always asking each oither if it is open or closed, just in case one of us forgot. By the way, the owners manual on this Universal engine even states that the fuel valve should be closed too, keeping fuel from being sucked into the engine while it is off. Although I can't figure how that would happen we generally close it, too. Chris
So... is she ready to float?
Hey Terry, Been a while since you posted anything.. figuired you must be getting close to a splash date and lots of details to take care of like the engine.. glad that turned out well. Thanks for the heads up on that... who would have thought all that would happen from a pretty straight forward idea... prob. just saved many a motor for those who read this site. How about some more pics of Bay Horse.. she must be looking good these days.. good luck. David Underwood "Freebird"
Hey Terry, Been a while since you posted anything.. figuired you must be getting close to a splash date and lots of details to take care of like the engine.. glad that turned out well. Thanks for the heads up on that... who would have thought all that would happen from a pretty straight forward idea... prob. just saved many a motor for those who read this site. How about some more pics of Bay Horse.. she must be looking good these days.. good luck. David Underwood "Freebird"
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