thanks, sounds like good advice. I just bought the boat and do not know when it was last cleaned
Inboard performance
- Thread starter Randall Schmidt
- Start date
Regarding cleaning the exhaust manifold/reservoir, is muric acid dip the best way? Does it come apart so you can get in it to scrap it clean? My shop says they cleaned it but I'm trying to find out how they did it and how they should have done it.
Shop tells me they used a brush and descaler to clean the manifold and suggests the descaler and a brass rod to clean the HX. Anyone have success with that method? any particular descaler you recommend?
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,176
Yes technique is most commonly used. Brass rod / Wood dowel. Just something that does not damage the lines in the HX. You are just pushing out any big pieces that are blocking the lines in the HX. Impeller bits, goo, you'll understand once you begin. Descaler is what is available or favorite. Muriatic Acid has been suggested because it is cheap and available everywhere. You can try LimeAway (maybe in you bathroom cupboard often used in home scale removal). These products use an acid of some sort to dissolve the calcium carbonate (scale). Here is another product that has a website and claims "RYDLYME". No experience with it. Maybe what you need.
I pulled off the heat exchange and used descaler and ran a dowel thru it. There was one rubber pieced of an impeller wheel in it but not much beyond that. Hard that causing all my problems. I hope this will solve it. I'm also replacing the fresh water pump (though the last one does not look bad) and a bunch of hoses. Guess that car radiator hoses won't cut so I'm trying to order the right replacement hoses online. My original repair manual lists part numbers that are helpful but the digram in the book has one less connection in the heat exchanger than my HX has. Please see photos. Any tips on what that is? I'm not at the boat now to re-examine what the adjoining hose goes. Could it have to do with my water heater that I've not yet tested and it probably doesn't work? Does anyone have a full set of hose part numbers and a source I can order from? I'm using DiscountMarine and am asking them this same question as the unexpected HX hose fitting.
Gotta have an inlet and an outlet for both the raw water and the coolant.
I believe what looks like the unnumbered hex nut to the left of the 11 in your parts diagram is where the nipple sticking up at the bottom left of your photo is screwed into your heat exchanger. That's your fourth connection. I think it is the raw water out but can't be sure without looking at your setup. EDIT: Looked at mine today and that is indeed the raw water out. It goes to a vented loop and then to the injection nozzle in the exhaust riser.
The diagram in this attachment shows it as 3/8 NPT:
http://inetmarine.com/skuni298633cnheatexchangercuni.aspx?gclid=CMy5-cX2iNACFQyffgodYLQHCw
That doesn't help you though with what size hose you need for that nipple on your HX. Gonna have to measure that.[/QUOTE]
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thanks so much!
that link you posted looks like the HX and the price is good on it. I can measure the diameter of the threaded
connection. Here is a new photo of my HX. My Hx has that same part number on it 298633 but that is also the same number listed in the engine manual that displays with one less connection on it.
I'll contact the business at the link you sent to see if they have the right hose.
that link you posted looks like the HX and the price is good on it. I can measure the diameter of the threaded
connection. Here is a new photo of my HX. My Hx has that same part number on it 298633 but that is also the same number listed in the engine manual that displays with one less connection on it.
I'll contact the business at the link you sent to see if they have the right hose.
that inetmarine site not only shows the HX I'm trying to match ,it also has a price about 1/2 of what I've seen elsewhere. I'm tempted to buy a new HX instead of re-installing my cleaned-up, but visually beat, 32 year old part. Do you have any experience with them? Is this a quality replacement part? Hopefully they can help me identify the hose I need.
I just measured that vertical threaded connection on the outside of the edge it is a 5/8" diameter and the hose run is 26".
I recall reading in the owners forum about replace zinc when you deal with the HX or at least inspecting it. I recall my surveyor saying the boat zinc looked good but cannot recall where he found it. From my photos of the HX do you see a place for zinc or is it under the boat on the shaft in my case?
You should have a zinc on shaft AND probably a pencil zinc in the HX. I don't see one listed in your diagram. Did I miss the make/model engine? My Westerbeke 10/2 has a zinc in HX.
The zinc is item 14 on your schematic (not visible in your photos but it is at the under side of the tube at the top end of the picture on Tuesday's post). It is a pencil zinc as described here:
http://shop.toadmarinesupply.com/sh...l+Zinc+Anode+1/8+NPT+X+2+inch§ionid=Zincs
It should be readily available at most marine supply shops.
You should check the zinc every three months or so until you get an idea of how fast you go through them.
If you pick up and shake the HX does it make any noise like there are small bits of old zincs rattling around in the end?
I don't know about the company or the particular HX I sent for an example. It was just something that came up in an internet search. If you have doubts about your HX you might be able to take it to a radiator shop and have them pressure test it for you.
I don't think the hose you are talking about (raw water out from hx) is a stock part because it would depend on the installation of the engine to the particular boat. Just get a section of the appropriate hose of the length and diameter you need.
You might want to consider getting an appropriate hose barb fitting instead of what looks like a pipe nipple in you photo.
My hx has a placard warning that it should be inspected monthly. Two months is the most I have ever been able to get before replacement is needed. On my m25xpb the zinc is cut very short. If you wait too long both the zinc and brass nut will need replacement.
Larry is right. I should have suggested more frequent inspections, especially until you get an idea of how fast they are degrading.
There's lots of Good Information about the overheating problem here, so I won't add to it. I'll just reply to the OP and say most Universal engines are 3000 rpm max, which means you SHOULD be able to run it at 2800 all day. Certainly 2400 is a good cruising RPM for that engine. You should NOT be having overheating problems at those rpms - the mechanic was an idiot.
Remember diesels LIKE to be run hard!
druid
Remember diesels LIKE to be run hard!
druid
so I descaled the old HX and had it tested and it came up as no leaks. I went ahead and replaced it anyway, along with all the hoses and the fresh water pump. I inspected the raw/sea water impeller and it looked fine and the one I purchased did not fit so I'll do that later. As a reminder, I already replaced the thermostat and cleaned the exhaust manifold. I took her for a test motoring and for 30 minutes or so she ran at 140 degrees. Then she spiked back up to 215 on a motor that should 180. I noticed a tiny leak in the lower thermostat housing - a crack. I've ordered a replacement for this part. My local mechanic, who has serviced the boat in the past, commented that I should flush the block. Earlier when he cleaned the exhaust manifold he partially flushed it by pulling the lower thermostat hose off when he ran water thru it. Now we found the drain plug/faucet on the starboard lower side of the block. I'll siphon out as much anti-freeze from the overflow reservoir and the exhaust manifold. Then I plan to open her up (open the drain) and she if she drips or is clogged up. If clogged, I'll remove the plug completely and if needed poke in the hole with a wire to open a flow up. Once I get her open, I'll attach a water hose to exhaust manifold/reservoir and flush her thru. My question is, how do I catch the flow and avoid having it simply go in the bilge and be pumped out into he harbor with the antifreeze residue? The drain is only inches from the bottom of the boat so there is no room to put a receiving pan underneath it. Can I hook up a hose and siphon it out? If I have crud in there it will clog my siphon but I can throw that out. How have others done this? A mechanic friend told me to drain it then fill it with water and toilet bowl cleaner and run the motor a while, then drain, fill with baking soda and water to neutralize the acid in the TB cleaner, drain that, flush with water and finally fill with antifreeze mixture. I'd like to avoid those several cycles of flushing if I can and if water alone has done the trick for you fellow boat owners.
when you replace the zinc do you need to drain the fresh water and/or the raw water system? I noticed the zinc screws up vertically into the HX from below. I imagine pulling that zinc out will be like pulling a plug and cause water or coolant to drain out. Seems like a bad design to me.
That will be "raw water ", not coolant, coming out when you remove that zinc. I hold a 16 ounce plastic cup under the the old zinc when unscrewing it and the water runs into the cup. Not a big deal even if it all goes to the bilge. It's not that much water.
No comments on the flushing (I've never done it) but it might be that you just had an air bubble in the system. 140 is too low and a spike to 215 or more is what usually happens to me after I have the coolant side of the system open because air gets into the system. Have you bled or "burped" the system?
This from the owners information:
"Should your engine overheat, first check coolant level to make sure it is not low which would cause air locks to develop. If air does enter the system, it may require a couple of fillings to remove the air pocket. A momentary increase of engine RPM to approximately 2800 to 3000 RPM may aid in moving the air from the system. In some cases it may require doing this 2 or 3 times. Do this just as you notice the temperature starting to rise above normal."
Check out this thread (thanks to Stu Jackson for his frequent reposting of this)
http://c34.org/bbs/index.php?topic=4518.0