tag:blogger.com,1999:blog-6458075112175110787.post7752487387694741731..comments2024-02-22T05:34:03.852-05:00Comments on The world encompassed: Exhaustive reasoning, part 1Rhyshttp://www.blogger.com/profile/00598445145507204424noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-6458075112175110787.post-65081427109841450082016-08-13T17:01:46.874-04:002016-08-13T17:01:46.874-04:00Yes, the SS ones are not only imperfectly durable ...Yes, the SS ones are not only imperfectly durable (I had an Onan one die in freshwater), they are often very hard to remove. You can get them in different dimensionals, and the size is based on the horsepower of the engine, which dictates necessary cooling throughput as per the raw water pump. I'm assuming you have a power boat? I know little about how those are set up in terms of waterlocks, actualy, but Vetus makes an excellent range. I went with Centek because it was simple and it fit and would be easy for me to fix if necessary. It's about the size of a soup pot.Rhyshttps://www.blogger.com/profile/00598445145507204424noreply@blogger.comtag:blogger.com,1999:blog-6458075112175110787.post-83164279143846343932016-08-12T11:06:32.500-04:002016-08-12T11:06:32.500-04:00I have a stainless steel waterlock which looks lik...I have a stainless steel waterlock which looks like just a vertical cylinder about 10 inches tall and 10 inches high. After two efforts to cure its leak by getting it rewelded, it is no better, it leaks slightly at the lower weld. The off-the-shelf versions are either too small ie smaller than the one I have (I am not sure how you are supposed to work out how much water they should hold)or too big to fit into the engine room. <strong><a href="http://teaguecustommarine.com/" rel="nofollow">Check Here</a></strong><br /><a href="http://academicfora.com/">Thailand Conference</a>https://www.blogger.com/profile/04667298100804893587noreply@blogger.comtag:blogger.com,1999:blog-6458075112175110787.post-46787006032455625392015-02-14T00:57:35.212-05:002015-02-14T00:57:35.212-05:00Part 2...
The importance of letting gravity rathe...Part 2...<br /><br />The importance of letting gravity rather than pumps or exhaust get the water out of the boat is emphasized here (with diagrams and pics): http://www.sbmar.com/articles/designing_a_marine_exhaust_system/ <br /><br />I do have a final thought, however: I have been victim of stuck or otherwise defective siphon plungers, the failure of which dropped water back down into the engine, and I feel a better solution is to simply have a vented loop with the vent line going (if possible) right out onto the deck, with special attention paid to where the actual break is vis-a-vis "downhill". With just a hose, there is no little piston to get cruddy with salt crystals, no problem. You remove the tube and flush it and then clamp it back on.<br /><br />Some other takes on siphon breaks are found here: http://www.marinemechanic.com/site/page66.html <br /><br />I hope this has helped. If you have any doubts, first consider the "uphill/downwill" factor, plus what would be the case in a pitching sea. If still unsure, consult a marine mechanic who grasps gravity. Too many boats seem to come up short in this department, and they need not if the subject is understood a little more clearly.<br /><br />Rhyshttps://www.blogger.com/profile/00598445145507204424noreply@blogger.comtag:blogger.com,1999:blog-6458075112175110787.post-17492907906824742072015-02-14T00:57:04.882-05:002015-02-14T00:57:04.882-05:00Sorry this took a few days, but it's been mise...Sorry this took a few days, but it's been miserable winter here! In short, no, you aren't wrong. I can't see how you can get away without a siphon break at the required height above the manifold below the waterline. However, I have some thoughts: The anti-siphon loop you see on my boat is cautionary because I have yet to rig the transverse exhaust. But I have to point out that my manifold is very close to, if not at, the waterline, so I shouldn't have this problem of no siphon break <i>if</i> the volume of the waterlock <i>plus</i> the volume of the hoses is not going to exceed the volume needed to back all the way up to your exhaust manifold, and unless you have a rather deep place in which to put the water lock, you may have to live with the anti-siphon loop. Another issue is that of over-cranking: you can flood the engine with rough starts because you lack the exhaust pressure to empty the "stock pot"; it fills and then there's nowhere for the new gushes of raw water to go. If you have a balky diesel start and a diesel under the WL, it's no sin to keep the raw water off until you've established a proper start: another reason to pay an extra ten bucks for "run-dry" impellers. Get started and then open the raw water. Of course, before you shut down, you can just as equally shut off the raw water and run for 15 seconds, which, depending on the RPM and the total volume of your waterlock and hoses (I have short runs side to side and so have less volume to consider), you can evacuate much of the water and sleep better. Just as easily, you could rig a solenoid, a check valve and a barb to the drain hole of your waterlock, and drain the system into the bilge and let the pumps deal with it. Again, too much complexity for me, but these ideas should work.<br /><br />But I digress, and I'm going to digress some more: Firstly, a proper way to do things is to change out impellers on an engine hours basis...don't risk them getting worn and losing vanes in the first place. Another caution, which I use on my other boat which has an Atomic 4, is to install a basket style filter between the raw water pump and the block/heat exchanger. If you have bits of vane, this will catch them, along with whatever muck, sand or vegetation that the main Groco/Perko strainer missed. It's a $50 fix that gives immediate warning of damaged impellers.<br /><br />Now, in the North Sea setup, as I understand it, the best way to go is to have a straight run to an elbow that's at a high point; this goes DOWN to a T that goes DOWN either side to port and starboard. That's tricky and I had to work with a digital bevel to figure out that I had sufficient height between the top of my manifold and the underside of my pilothouse deck. I'm counting on the "air" or "high" side of the double exhaust to allow, when switching off, the water past that elbow to drain out of the boat. The rest will fall back into the boat. Either seacocks (for extended sailing) and/or exhause flaps should keep water from getting back up the spout, so to speak, but I can't discount a siphon break entirely as the fully laden boat, or the boat sailed in rough beam seas or heavily heeled, might see water ingress. So I, too, with a more favourable geometry, might not rule out a siphon break, either.<br /><br />Part 2 of my reply below...Rhyshttps://www.blogger.com/profile/00598445145507204424noreply@blogger.comtag:blogger.com,1999:blog-6458075112175110787.post-29265030971511773672015-02-11T05:59:17.754-05:002015-02-11T05:59:17.754-05:00Hi Rhys, I'm in the process of converting our ...Hi Rhys, I'm in the process of converting our boat to a north sea exhaust and came across your blog. I was especially pleased to see that I could lose the anti syphon loop. I've been dwelling on that thought a day and am confused. In our setup at least the engine exhaust manifold and water injection elbow are all below the waterline, as is the water lock. So; the engine is switched off, the raw water impeller is old, maybe lost a fragment of blade, the sea water syphons through the system and fills the water lock, rises up the exhaust hose until it reaches the exhaust manifold and floods the engine. Unless there is an anti syphon loop. Am I wrong? Have I missed something? I hope so cos I'd love to lose that loop too. I know the seacock ought to be off but we all know it won't be. <br />Thanks for your thoughts<br />RichAnonymoushttps://www.blogger.com/profile/14758249153795051197noreply@blogger.com