#26
IP: 73.133.67.239
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I spent the day at the boat yesterday for data gathering. I think I
pretty much accomplished all that I had planned for. First, I checked the coolant level. Both heat-exchanger and overflow tank were completely full. This was expected since I only ran the motor for maybe 10 minutes last week (see my very first posting in this thread). Next was the pressure test of the exhaust manifold. It was not 100% conclusive because of 'technical difficulties.' I will spare you the details, I had forgotten my bicycle pump at home and ended up buying two new ones on the way, both with problems. Also, I have the suspicion, the guy at Home Depot sold me a cap for the hose barb that had slightly wrong threads. I ended up using A LOT of teflon tape but I suspect there was STILL a small leak at the hose barb. So, my contraption did not hold pressure for a long time, it went from 4psi to 3 psi over ~15 minutes but I am 99% sure that this was due to a slow leak either at the hose barb or in the pump itself (which I could not disconnect since doing that caused immediate loss of pressure). Then I did the spark test with the cold motor, using a fifth spark plug as advised. It went well but I have absolutely no idea whether the spark is blue and snappy or not. I tried attaching two videos, one taken after I just turned the motor on, completely cold. The second one was taken after two hours of running under load. Unfortunately, I am not allowed to attach mp4 files, and the files are also too large to upload to the site anyway. To me the sparks look pretty much identical but I would not even know what to look for. I would love to get experts to look at the videos but I don't know how to get this on the forum. Then came the main part, running the motor under load, at about 1300 RPM for a good 2 hours and measuring the temperature. After the first 15 minutes or so, I closed the engine room door, so conditions should be quite realistic. Results are shown in the attached graphics. I measured at 6 locations: 1) on the hose going into the coolant pump (dark blue line in the figure) 2) on the hose from the motor block to the exhaust manifold (red) 3) on the hose from exhaust manifold to heat exchanger (yellow) 4) on the metal of the coolant filter* (green) 5) on the brass 'tee' with the gauge sensor (brown) 6) on the top of the motor block (light blue) *The coolant filter is the one Indigo recommends to run temporarily when installing their system. I decided to leave it in 'just in case'. My understanding is that most commercial installations (e.g. truck engines) have coolant filters permanently installed. BTW, I checked the filter and it was clean as a whistle. Observations: a) It seems that all temps reach a stable state very quickly, within about 10 minutes. There are some 'spikes' but I think these are measurement errors, with one exception which is the very last data point (more on that later). b) Some results are surprising. The temperature at the sensor (brown line) is pretty constantly between 130 and 140, but the gauge showed 170. I have no reason to assume the gauge is wrong. I suppose that the outside of the brass 'tee' with the sensor is simply 30-40 degrees cooler than the coolant inside. c) I expected that the temperature on the coolant filter (green line) was the same as in the drain from the exhaust manifold (yellow) since it is the same coolant that flows in both. Instead, the filter is about 10-20 degrees warmer. I suspect this has to do with the better heat conductivity of the metal filter housing compared to the rubber hoses. d) Temp at 'Exit exhaust manifold' (yellow) is nearly consistently lower than at 'Exit motor block' (red). This makes not sense, the exhaust must increase the temperature. Again, my only explanation is that there must be a difference in the hoses. Both are rubber hoses but maybe one is thicker, or otherwise less heat conducting than the other?? Despite these inconsistencies, overall, I think this is pretty healthy behavior. There was, however, some excitement at the very end of the test: A keen eye will notice that at the very last data point (unfortunately cut off in the graphics), all temps go up. This is because the V-belt broke!! I knew it was suspect and it was slated for replacement but I thought this was a good opportunity to test it 'to destruction' since I was keeping a close eye on the motor. I actually noticed it shredding itself during my temperature measurements until finally it gave up the ghost. Haven't replaced it yet since doing that will be more pleasant when the motor is cool. I may still have a leak, though. I have the habit of putting a disposable diaper under the motor to catch any drips of oil or water. When I was packing up shop yesterday, I noticed that the diaper was completely full, I would guess there must have have at least a quart of liquid in there. I did not connect the dots up until when I was driving home: I had replaced the diaper last week and I don't think it rained this much (some rain water always find it way into the bilge). So I will have to hunt for a leak. This would explain one of the mysteries (where did the coolant go). So where is the leak? I wonder if these very thin paper gaskets on the pumps really are enough (they are commercially made and bought at MMI). Should I coat them with anything? Also, if there is a leak, I have no explanation why I did not notice it last week. And, finally, why the motor stopped, is still unclear. To me the spark looked as good after 2 hours as at the beginning (perhaps due to my ignorance) and the motor ran perfectly fine and round. Perhaps I should drain the carburator and see if anything lurks in there? Haven't done this in a year. |
#27
IP: 73.19.60.36
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this
+1......... 10 characters
__________________
'69 Newport 30 MKI Hull #20 |
#28
IP: 73.19.60.36
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+1 10 characters
__________________
'69 Newport 30 MKI Hull #20 |
#29
IP: 70.185.132.167
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Quote:
There may be a lose or intermittent disconnect in the wiring. If you have an electronic fuel pump and there is wire that goes from the fuel pump to the starter let this wire loose at the starter and inspect it. On my A4 the insulation was worn and the wire was shorting out back by the distributor where the wire turns towards the starter solenoid. Kept me guessing for many months. TRUE GRIT |
The Following User Says Thank You to JOHN COOKSON For This Useful Post: | ||
ernst (10-07-2019) |
#30
IP: 73.133.67.239
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Oh, when I see my posting now, the graph is only available for downloading. Isn't there a way to include the graphics in the text, or at least as a little icon that makes it pop up when you click on it? All I could find on this page to include a file from a URL but it seems only URLs with https:// are allowed, not on my own file system. Help, please?
tx |
#31
IP: 73.133.67.239
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Quote:
As for the low-voltage wiring, yes, I should follow that up. Fuel pump is mechanical. tx |
#32
IP: 73.133.67.239
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Another couple hours work on the motor. I replaced the V-belt, installed it at 130# when new and tightened to 90# after 5 minutes of running, per instructions from the manufacturer (Gates). Was able to use my Krikit gauge rather than using the 'rule of thumb' and I think the belt was too loose previously. It still worked for a decade so I don't complain.
The more I think about it, the more I feel that one of the 'mysteries' may be solved: where the coolant went. My use of the diaper under the motor may have obscured the gradual loss of the coolant. At least this is my working hypothesis. As for how it got lost, I am not quite sure yet. I re-tightened all hose clamps even though there was no hint of a loss there. I replaced the paper gasket of the coolant pump again (and discovered that I had inadvertently put two in but that would not have caused a leak, right?). Following John Cookson's advice in another thread, I put a thin layer of PTFE pipe dope on both sides of the new gasket. Did not see any leaks during the 5 minutes I ran it (for the final tensioning of the V-belt) but that may not mean much. Question: Based on the coolant I collected under the motor, I think I am still about 2 qts shy of what should be in the system. Will it be sufficient to keep the overflow reservoir filled and let the motor 'burp' out the air? Or do I have to go through the process of disconnecting the various hoses etc and fill up the block as prescribed in the Indigo instructions for the first filling of the system? Oh, btw, I found the snap ring from the impeller that I thought I had lost, in the bilge! But I suppose there is no reason to put it back on, right? |
#33
IP: 128.220.159.8
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I went sailing this weekend and everything worked flawlessly. So I will conclude that the mystery shutdown was due to a cosmic ray and I hope that it will not re-appear. The good thing is that I learned a few things on the way so the effort was not wasted. Thanks again for your help!
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The Following 2 Users Say Thank You to ernst For This Useful Post: | ||
Administrator (08-26-2019), GregH (08-27-2019) |
#34
IP: 97.93.70.7
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Ernst, thanx so much for chiming in. I is always good to hear the efforts were well worth while.
Dave Neptune |
The Following User Says Thank You to Dave Neptune For This Useful Post: | ||
ernst (10-07-2019) |
#35
IP: 207.118.20.35
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Those darn cosmic rays will get you every time. Glad your engine is running well.
Sometimes, when I suspect a slow leak, I place some unbleached paper towel, natural color, under the area suspected. When it gets wet it becomes noticeably darker. On my boat, there is a high point in the curve of the water hose between the bottom of the heat exchanger and the Fresh water pump. This curve is to keep the water hose off the engine, because I mounted the HX so that the bottom of it is about 2 inches away from the side of the manifold. If I drain the coolant to change the impeller, then reattach the hoses and fill the heat exchanger, air remains in the high point of the hose. This keeps the pump from working to bring water from the HX, and the engine will overheat. It is also hard on the impeller. I have learned to briefly remove the intake hose on the pump, to enable that air pocket in the hose to fill with water, then refill the HX. The purpose of the snap ring on the impeller is to keep the shaft from moving back and forth, so the impeller and the seals last longer The newer Moyer flange pump, which has no grease cup, has no snap ring on the impeller. The packless bearings prevent the shaft from moving. I suspect when I rebuilt my pump four years ago, I did not tap the bearings in all the way to meet the stops on the shaft. As a result the shaft could "float", to use the Moyer Co. term, and the seals failed this year, leading to milky crankcase oil. I still suspect you may have an intermittent coil that could shut down after some hours of running, and getting too hot. I have a Moyer coil with no external resistor. I have left the ignition on overnight with no apparent ill effects at the time, but much later had to replace the coil, which still worked, because the rim around the top was rusty and leaking. I had a bad overheating episode once which may have cooked it. I have never had the engine suddenly quit because of a failed coil, but I rarely run it for more than an hour at a time. I think I have replaced coils twice in 20 years. Ernst, your efforts to keep learning about your engine will result in many years of trouble-free operation. Happy Sailing! |
The Following User Says Thank You to capnward For This Useful Post: | ||
ernst (10-07-2019) |
#36
IP: 128.220.159.8
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I may have to rethink the cosmic ray theory of mine. I went sailing this weekend and, just as I was about to enter the planned anchorage (in Worton Creek, for the Chesapeake cognoscenti), the temperature alarm came on! I anchored right where I was, in the approach to the Creek, and ended up staying there the whole night.
So what caused the problem? I am pretty sure now that the water pump is leaking from the weeping hole: when I feel there, it is definitely moist. Rather than blaming a cosmic ray, my new theory is that this caused a slow leak which was hidden by my habit of keeping a diaper under the motor. I should probably be prepared for this to happen. I have NEVER been able to get the impeller off its axle without the axle coming out. I understand that this is not good for the seals, right? I have an Oberdorfer pump and I understand there is a rebuild kit for $153.- (https://moyermarine.com/product/repa...mp-csob_09_70/). There is also the all-new-all-improved Moyer pump for about twice that much (https://moyermarine.com/product/mmi-...p-csob_00_365/). I am reasonably handy (I think) but I am not a mechanic and pressing bearings or seals on axles is not something I am familiar with at all. So I am tempted to go whole-hog and get the new pump (it is 100% compatible, right?). Good decision? What say ye? |
#37
IP: 32.211.28.40
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I used an Oberdorfer pump for years, continually dealing with seals & leakage. Never was able to get it 'right'. But being raw water cooled, it didn't really bother me - there was plenty more water where that came from.
Then I changed to glycol cooling, and the leakage from the Oberdorfer was suddenly critical - it was like losing blood! Changed to the Moyer pump - no regrets. |
The Following User Says Thank You to Al Schober For This Useful Post: | ||
ernst (10-08-2019) |
#38
IP: 70.185.132.167
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Quote:
When I finally threw in the towel and went with the Moyer pump my cruise running temperature dropped 40 degrees - from 160 to 120. Nothing else was changed. No acid flush either. The Moyer pump is just plain a better pump. TRUE GRIT |
The Following User Says Thank You to JOHN COOKSON For This Useful Post: | ||
ernst (10-08-2019) |
#39
IP: 128.220.159.8
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Quote:
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#40
IP: 207.118.20.35
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When you buy the new Moyer pump, get the rebuild kit too. It has directions for replacing shaft, seals, and bearings. Not too hard to do with the right tools. You will still have to monitor the pump for leaking, and fix it when it does. The seals on my Moyer flange pump have failed twice in ten years. The first time it overheated the engine, putting coolant into the bilge. The second time the engine ran hotter but ok, and coolant water got by the oil seals into the crankcase.
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#41
IP: 97.93.70.7
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Caution
Ernst, do not use any extra or thicker/thinner gaskets on these style pumps. The width of the impeller plus the gasket is what the clearance is set for. If you go to a thicker one the pump will loose pressure as the impeller vanes will allow water to leak past. And to thin will pinch and destroy the impeller.
Dave Neptune |
#42
IP: 67.176.201.200
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I'[[ chime in a little here. Here in Chicago we have short Lake Michigan season - about 5 months. On my early model A4 I upgraded from a little "Sherwood" pump to the Ober about 25 years ago. With the old style Dole tstat the beast runs a steady 140 F raw water. I pull the shaft out/impellar out every season for winter layup carefully using small needle nose pliers and lubricate it. I did slightly bevel the shaft end to minimize seal damage on extraction /install. every other outing I give the grease cup a half turn After examining the impeller I usually change every 2 -3 seasons no matter [snap ring is important] and change the moyer gasket almost every year. Cooling/pump has been problem free so far with this routine.
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#43
IP: 68.33.43.122
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FWIW, I placed the order for the new (MMI) pump today. I did order a spare impeller but no rebuilding kit. |
#44
IP: 68.33.43.122
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Quote:
I also put the plumbing goop on both of the gaskets that someone recommended (was it you?). This has cured the (very slow) trickle of water/coolant through the face plate. |
#45
IP: 68.33.43.122
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Quote:
Was that wrong? If yes, what effect would it have if the snap ring is omitted? As you may have seen earlier in this thread, I lost it and did not care about it because of what I just wrote. I accidentally later found it and this time I threw it away for the same reason. Please tell me I did not do something stupid... |
#46
IP: 207.118.20.35
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The new Moyer 502 flange pump you ordered has no snap ring at the impeller, no grease cup, and no gasket. Only a tiny O-ring. It's better to have the rebuild kit on hand in case you develop a bad leak, then you can fix it on the spot instead of waiting several days for the kit to arrive. The kit does not include a new pump housing or backplate. It does include new O-ring, impeller, bearings, seals, shaft, grease, and directions. https://moyermarine.com/product/repa...p-csob_00_461/
If your experience is like mine, you have four years before you will need to rebuild the pump. But I run the A4 100 hours a year or more. Replace the impeller every two years, more if you use the engine a lot. The snap ring on the old pump was there to keep the impeller from wearing out and forcing water past the seals. Last edited by capnward; 10-11-2019 at 02:45 PM. Reason: add 'at the impeller' |
#47
IP: 68.33.43.122
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Quote:
Snap ring: So it seems the wisdom I gleaned from the internet ('snap ring is only used for transport') was wrong! It may not be by chance that the pump worked fine for at least 18 years (plus the time it was in there before I bought the boat), and then failed after it ran for a few hours without the snap ring. Exactly in the way you describe it: forcing water past the seals. I guess I learned an expensive lesson |
#48
IP: 24.152.132.140
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Do you remember the source of the wrong information? Sailboatowners or one of the Catalina forums?
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#49
IP: 68.33.43.122
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No, I don't remember. Definitely not Catalina.
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#50
IP: 24.152.132.140
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OK, thanks. I asked because there's a guy who frequents both SBO and more than one of the Catalina sites who advocates discarding the Oberdorfer impeller snap ring for exactly the reason you read on the internet.
I'll stop there if you get my drift.
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
Tags |
circlip, coolant, snap ring, water pump |
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