I have a 1980 C27 and a 5411 Universal diesel with the Oberdorfer water pump. For this setup what brand of strainer is being used by those of you that have one? And how is it hooked up? It would seem there would have to be some re-plumbing. Thanks for any help out there.
C27 Raw Water Strainer
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Your engine uses very little water so virtually any strainer will suffice. I'd suggest you not get a small one though as the limiting factor with this engine isn't capacity of the filter but the fact that small filters clog faster so bigger is always better
Don, your are correct, the 5411 uses very little cooling water so I agree a smaller unit would probably be OK. I don't have a pressing need to get one. I just thought it would be something that would prevent problems and is a relatively easy add-on.
Our 82 27 has one installed, but I don't know if it's original. It's rusty stained and leaks a bit, so I bought the one Catalina Direct sells and will replace it soon (one of many projects on the new boat). Problem is when the weather is nice I'd rather go sailing! One advantage of the central California coast is year round sailing, in fact, the post frontal days are often some of the nicest.
Rob
Santa Cruz
Rob
Santa Cruz
Rob, thanks for the reference. Never thought to look at Catalina Direct. Can you describe for me how it is plumbed? I'm guessing that it would be mounted to the right or left in the engine compartment. Then, with additional 1/2" hose, plumbed just after the inlet seacock and before the mixing tee.
Just like you thought, it's on the port side, after the seacock and before the tee. Our system also has a shut off valve on the return line between the thermostat and the tee. It's closed, but I don't know why. I don't get any reading on the temperature gauge, but I don't know if that's an electrical, gauge, or real temperature issue. Another mystery and project.
I wonder if because the return line is closed you are continuously drawing in more water from outside the boat and, consequently, more water running out the exhaust, even when the engine hasn't fully warmed up. My boat spits very little water out the exhaust until the temp gauge starts moving beyond 150 F. Then I get more water out the exhaust and the temp goes back down to 150 F. My temp gauge starts at 100 F. Maybe your engine isn't heating up enough to move the needle off the lower end of the temp gauge. Are you getting a continuous flow of water out the exhaust right away after start up? The maintenance book on the 5411 says that the normal operating temperature is between 135 and 150 F. I've always been concerned that maybe I was running a little too warm. When I pulled my boat for the winter I had the marina winterize the engine. What they do is with the boat in the slings they hook up a large rubber gasket over the water intake strainer. The gasket is connected to a hose which supplys antifreeze from a large tank that is mouted on top of a small builidng. The tank is above the level of the boat and so gravity keeps a constant pressure on the antifreeze supply. When the engine was started the antifreeze started flowing immediately from the exhaust and kept doing so the whole time of the winterizing process. The engine temp never got above 125 F and took a long time to get to that temp. I couldn't understand why the motor didn't heat up to the normal 150 F. The only thing I could think of is that since the antifreeze tank was above the level of the engine(unlike the sea water level when the boat is in the water) it was forcing more water out the small thermostat bypass that I think these engines are set up with. I didn't know about this bypass but a mechanic at the marina said all engines are set up that way to keep some water flowing to cool the exhaust line. I thought that water just kept circulating in the engine until the thermostat opened up then allowing water to flow out the exhaust and draw in more seawater. I still have a lot more to learn about how these engines operate.
I changed the strainer yesterday, and opened the valve. Started the engine and there was very little water coming out of the exhaust. It finally started registering on the temperature gauge, but when it started going over 160 (still very little water out the exhaust) I got nervous and partially closed the valve. Water started exhausting and the temperature dropped. So the gauge works, but may not be accurate (will check soon with an IR temp. sensor), or the thermostat doesn't open unless it gets hotter, or there;s more pressure on it. I think I'll end up pulling the thermostat open, just to see what's going on in there.
Marchem, sounds like when the valve is closed you get a continuous draw from sea water and that keeps the temp low. I have an IR thermometer and the temp on my engine is at 150 - 153 F when fully warmed. I'm going to ask a local diesel mech about whether these engines have a bypass and if such a valve is a method to contrl engine temp. Will keep you posted. It'll be next week before I call the mechanic.
I also have the 5411 engine on my 1980 C 30 - same year as yours.
As far as your question about a sea strainer, I & most of us just have a bronze slotted sea strainer which is fixed to the outside of the hull, surrounding the raw water intake.
It blocks the big crud from getting in, but has a large enough diameter to help prevent blocking it with any debris. The 5411 cooling loop confused me as well at first. I leave the valve shut going to the thermostatically controlled loop, because it stops water from discharging through the water muffler, until the thermostat opens up at 150 deg. While this is designed to allow the engine to warm up faster, & hence run slightly more efficiently, it makes me uneasy to see no cooling water coming out of the transom when starting up. It can take 5-10 minutes or more before the thermo. opens up & allows raw water through the muffler. It can get so hot that it makes steam out of the exhaust. I've gotten the advice from several marine mechanics & they don't see any real advantage to using the thermo controlled cooling loop, unless the weather is very cold & you wish to warm the engine faster. But it makes me uneasy to wait so long for cooling water to flow through the block to water muffler. The muffler should not get so hot that it steams. This can shorthen its lifespan. Although my water muffler is rather large & it still seams to take about 30 seconds of running before the pump can fill it enough for discharge though the stern.
ps. The Oberforfoer pump works well enough, but it has a small grease cup on it that will rust away after many years. Mine broke off & started leaking water. So I advise you to replace it before hand, if your pump has this feature.
Otherwise the 5411 is a tuff lil' workhouse that I have few complaints, other then I wish it had a lil more oomph. But I would not trade its reliability for a bigger engine.
As far as your question about a sea strainer, I & most of us just have a bronze slotted sea strainer which is fixed to the outside of the hull, surrounding the raw water intake.
It blocks the big crud from getting in, but has a large enough diameter to help prevent blocking it with any debris. The 5411 cooling loop confused me as well at first. I leave the valve shut going to the thermostatically controlled loop, because it stops water from discharging through the water muffler, until the thermostat opens up at 150 deg. While this is designed to allow the engine to warm up faster, & hence run slightly more efficiently, it makes me uneasy to see no cooling water coming out of the transom when starting up. It can take 5-10 minutes or more before the thermo. opens up & allows raw water through the muffler. It can get so hot that it makes steam out of the exhaust. I've gotten the advice from several marine mechanics & they don't see any real advantage to using the thermo controlled cooling loop, unless the weather is very cold & you wish to warm the engine faster. But it makes me uneasy to wait so long for cooling water to flow through the block to water muffler. The muffler should not get so hot that it steams. This can shorthen its lifespan. Although my water muffler is rather large & it still seams to take about 30 seconds of running before the pump can fill it enough for discharge though the stern.
ps. The Oberforfoer pump works well enough, but it has a small grease cup on it that will rust away after many years. Mine broke off & started leaking water. So I advise you to replace it before hand, if your pump has this feature.
Otherwise the 5411 is a tuff lil' workhouse that I have few complaints, other then I wish it had a lil more oomph. But I would not trade its reliability for a bigger engine.
Jrowan, I get the steam out of the exhaust opening too. I don't have a muffler though. My exhaust line just is the high temp wire wound flexible hose that runs straight to the exhaust opening. I don't have a shutoff valve on the coolant return line either. I wonder if I should install one? But don't you need the return line open otherwise isn't there a lot of pressure with the cooling water trying to esacpe out the smaller bypass at the thermostat? With the return line open there is a constant circulation of the cooling water and none of this pressure I'm referring to. Maybe it's OK to have the return line closed. I guess i'm just thinking of the impeller spinning around trying to force water through the cooling channels. I'm still confused. I also had a leaking grease cup. I soldered it and so far the solder is holding. It took two attempts to get the solder fix to work as the steel doesn't accept the solder that well, but it finally did. I did see a new water pump on line that eliminated the grease cap. I think it was around $250 or near that.
As you, I do like this little engine. Even though mine is 32 years old it starts up immediately and seems to run flawlessly. I've read that it's better to have a heat exchanger on an engine but I really like the simplicity of having fewer things to go wrong. I only have a C27 so it is strong enough for my boat.
As you, I do like this little engine. Even though mine is 32 years old it starts up immediately and seems to run flawlessly. I've read that it's better to have a heat exchanger on an engine but I really like the simplicity of having fewer things to go wrong. I only have a C27 so it is strong enough for my boat.
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Some of the manuals for the 5411 show the cooling water flow and the return line (there's no valve in schematic). The design is certainly to have very little flow out the exhaust with maximum return until the thermostat opens, and it starts dumping water into the exhaust. I guess the trade off of closing the return line is how much longer it takes the engine to warm up vs. keeping the exhaust cool. I do agree that the water pump is working harder with both the return line and thermostat closed.
Luckily the water pump on our engine was replaced recently by a PO with the new style Oberdorfer; no grease cup.
Luckily the water pump on our engine was replaced recently by a PO with the new style Oberdorfer; no grease cup.
Marchem, I think I will probably just keep mine the way it is. It runs good and doesn't overheat. But I wish it would run 5 - 10 degrees lower than it does (currently 150-153F, the upper limit of normal). I still would also like to understand why on the fall haulout and winterizing the antifreeze started flowing out the exhaust immediately, and at a pretty strong flow rate, instead of after heatup and the thermostat opening up. The higher flow rate confuses me because when motoring and the thermostat opens up the amount of water coming out the exhaust is still kind of minimal but still much greater than just after startup. As I indicated earlier it has to be because the antifreeze tank being up high. I think that would put much more push on the fluid in the cooling lines and therefore push more out of the thermostat bypass opening, if there is such a thing.
Can anyone describe this thermostat bypass? As I understand this bypass allows a little cooling water to enter the exhaust even if the thermostat is totally closed. Is this bypass a small hole in the thermostat(I think I read that somewhere) or a separate channel in the exhaust manifold leading to the exhaust line?
Searching internet found this. Is this what we have on the 5411 in concept? The description refers to cars but does talk about a wet exhaust.
http://www.hardin-marine.com/p-1256...yle-stainless-steel-water-outlet-divider.aspx
This is definitely not thermostat housing for the 5411 so maybe there is a bypass opening built into the thermostat itself.
Searching internet found this. Is this what we have on the 5411 in concept? The description refers to cars but does talk about a wet exhaust.
http://www.hardin-marine.com/p-1256...yle-stainless-steel-water-outlet-divider.aspx
This is definitely not thermostat housing for the 5411 so maybe there is a bypass opening built into the thermostat itself.
I think it's common for a thermostat to have a small hole in it for a bypass, but I don't know if that's the case for the 5411. I'm ordering one soon, so if no one answers by then I'll let you know.
The housing you refer to has 3 ports. So does the 5411, but only 2 of the ports are external, the third is where it connects to the manifold. You still have water coming out of the engine, then going to the exhaust, or the inlet of the water pump (via a tee), or some of both.
Rob
C27 #5024
Santa Cruz
The housing you refer to has 3 ports. So does the 5411, but only 2 of the ports are external, the third is where it connects to the manifold. You still have water coming out of the engine, then going to the exhaust, or the inlet of the water pump (via a tee), or some of both.
Rob
C27 #5024
Santa Cruz
I've never had the thermostat or housing apart. Will be interesting to hear about what it looks like. There's a marina in my neck of the woods called Torresson Marine and they work on and supply parts for the 5411. I'll try to call them this week sometime.
I got a new thermostat today. There is a small hole in it, so there should be some flow to the exhaust at all times, unless crud has blocked the hole.
I'll pull the old one off soon and see what it looks like.
I finally talked with the mechanic and he confirmed what I thought. With the large tank of antifreeze above the level of the engine there was head pressure on the column of water feeding the engine. This head pressure forced more water than normal out bypass opening in the thermostat. Sure is nice to know how things work. These things are simple in concept but if you've never experienced them before they are quite a challenge to understand.
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Ajay, I don't have a picture of my engine, but the thermostat controlled loop is not a small opening on the side of the thermostat. If you look how your water lines are plumbed, there is the main inlet hose from the water inlet sillcock. It runs up to the water pump. Then the water pump sends raw water cooling into the engine. The water then exists the block at the rear of the engine. My engine has a Y valve at the outlet hose which when open, allows water to flow out to the water muffler, or back to the thermostat controlled loop. When this valve is closed water flows only to the outlet / muffler. When open it allows water that has already been warmed by the engine back into the cooling circuit again. This allows the engine to warm up faster, & hence is supposed to improve start up efficiency & performance by getting the engine to operating temp. faster. The thermostat only opens up when it has reached 130 degrees. Like I posted before, I don't really like this because it can take 10 minutes or so until it warms up enough to allow raw water discharge out through the transom. So you don't really know if the pump is even cooling or flowing correctly, until the point at which it will quickly overheat if the thermostat doesn't open up. This is how a lot of car engines wind up overheating: from a failing to open thermostat. You could just remove it all together, but I just use the valve that opens the coling loop, unless I'm starting out in really cold weather. I'll try to find a pic of a 5411 which shows the plumbing for the raw water cooling. Its possible that your C 27 is plumbed differently from my C 30, & I know that access to view the engine is more difficult in your boat. Hope this helps & doesn't confuse you more.
Jrowan, this is a picture of my engine. The hose running from the block to the exhaust manifold is at the front of the engine and can be seen in the attached photo right next to the black Universal label . I don't have this Y valve you speak of. This must be because you have the muffler set up on you C30. I have no muffler. Out of the thermostat housing, which is at the back of the engine one hose runs from the bottom of the housing and is the return/recirculation line that goes back to the mixing tee. The other one runs from the top of the housing and snakes back to its attachment to the exhaust line. You can see this line just behind the trailer type electrical connector.
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