Flushing the FW side

[jeffjd]

I cannot tell from the picture but it seems like 40 gauge black steel pipe would work. I did it with larger gauge that was overkill and will out last the engine. Skip the galvanized steel.

Or weld it for for the short term and fix it in your slip next week.


Sent from my iPhone using Cruisers Sailing Forum

[jimbunyard]

Originally Posted by Strait Shooter

I just finished the removal, cleaning, and replacement of the heat exchanger on my Perkins M-50.

The space in between the tubes in the heat exchanger was a solid mass of hardened gunk.

I believe two issues have been at play in my engine. There was a leak between the fresh water side and the raw water side at the rubber boot interface. There was no sealant used between the rubber boot and the tube stack originally. I have some pics on another device that I'll post later, and it becomes obvious that there was some blow by happening which resulted in a mixing of fresh water and raw water.

The second issue falls at my feet as an inexperienced diesel engine operator. When I put my boat on the hard last winter, the yard boss told me to put some anti freeze in both the raw, and the fresh water cooling systems. He advised that the "pink" R.V. type antifreeze was the only sensible thing to do. He never mentioned that you should flush your system first to avoid mixing two anti freezes that don't belong in the same room together, much less my engine. I'll take the hit on that one...maybe I could have known better.

Repeated flushing of the heat exchanger when it was off the engine was amazing. The amount of crap I got out of the aluminum body is amazing.

Today when I reassembled everything, I filled it with the proper mix of antifreeze and ran the engine. The engine is still running in the 195-200 F
range, and I was expecting it to be running a little cooler than that.

I don't think I did anything wrong, but I guess it's possible.

The exhaust smoke is greatly diminished BTW.....

John,

Does this mean that you didn't send the exchanger out to be cleaned, and that you just cleaned it yourself without dis-assembling it?

Also, after reassembling the engine and running it, did you flush the entire system?

Given the amount of corrosion described, it you didn't, you need to do so.

Either A64's or Mainesail's continuous flush recommendations, or a tap water fill, run and drain repeated several times will help, whichever works best for you, but the key things are to do this with the t'stat out and to use some type of proprietary engine cooling system flush at some point. (You run it without the t'stat to get maximum coolant flow through the engine)

If the freshwater side of the heat exchanger was gunked up, then certainly the passages in the head, block and oil cooler are/were, too. Until this is addressed positively the engine will continue to run hot. I would absolutely remove the oil cooler and clean it, the temperature of the oil has a direct influence on both the running temperature and the life span of the engine.

195-200 seems hot to me too, given the area you're running in, 180-185 would seem more normal.

Regarding propylene versus ethylene glycol, I prefer the green. Sure, it's poisonous, but it seems much more permanent to me, and I don't plan on drinking it. And while I'm not recommending this practice, the ethylene glycol antifreeze in my 49 year old tractor has been in it for at least 18 years, which is the length of time it's been under my care....

[Strait Shooter]

Originally Posted by jimbunyard

John,

Does this mean that you didn't send the exchanger out to be cleaned, and that you just cleaned it yourself without dis-assembling it?

Also, after reassembling the engine and running it, did you flush the entire system?

Given the amount of corrosion described, it you didn't, you need to do so.

Either A64's or Mainesail's continuous flush recommendations, or a tap water fill, run and drain repeated several times will help, whichever works best for you, but the key things are to do this with the t'stat out and to use some type of proprietary engine cooling system flush at some point. (You run it without the t'stat to get maximum coolant flow through the engine)

If the freshwater side of the heat exchanger was gunked up, then certainly the passages in the head, block and oil cooler are/were, too. Until this is addressed positively the engine will continue to run hot. I would absolutely remove the oil cooler and clean it, the temperature of the oil has a direct influence on both the running temperature and the life span of the engine.

195-200 seems hot to me too, given the area you're running in, 180-185 would seem more normal.

Regarding propylene versus ethylene glycol, I prefer the green. Sure, it's poisonous, but it seems much more permanent to me, and I don't plan on drinking it. And while I'm not recommending this practice, the ethylene glycol antifreeze in my 49 year old tractor has been in it for at least 18 years, which is the length of time it's been under my care....

Good Morning Jim,

Thanks for asking, and yes, while I originally planned on taking the tube stack from the heat exchanger into a shop, i couldn't get the tube stack out of the heat exchanger and had to remove the heat exchanger from the engine. I spent the better part of an evening using vinegar and picks to release enough of the crud (not rust, crystallized something or other) from around the manifold sleeve until I could get the stack to release. When it did i was enlightened as to how the heat exchanger had failed in it's purpose. The tubes were only blocked at one end of the stack, and it was superficial at best. However, the tube stack had so much build up BETWEEN the tubes that it was impossible for any coolant to to pass through it. It was the same crystallized crud that I was now seeing in every nook and cranny. I had chunks the size of marbles in a not unsubstantial amount on the workbench while I was getting everything apart.

At this point I decided not to go to a radiator shop, and began a scrubbing and soaking of the tube stack and the manifold in a vinegar bath while I waited for new gaskets, and a thermostat to arrive. I got it clean! On reassembly I did indeed flush the engine repeatedly with no thermostat, using Maine Sail's method (and yet again, thank you Maine Sail for sharing your considerable knowledge with everyone the way that you do).

After I got it all back together, as I stated previously, the temp, while lower, was still on the high end, and shouldn't have been, as you yourself have noticed. After jointing a smoke and conjugating on it, I hooked up the red dot heaters, and secondary electric water pump that I had been installing when all of this started. I had previously made a closed loop with the coolant lines and placed them ABOVE the level of the water pump. I suspect I had no coolant flowing over the temp sensors and was getting a false temp indication. Is that possible, do you think? Anyway, when I hooked the system up, and turned the secondary electric water pump on, the temperature stays at 175. I'm going out today to test it under load.

Here's a picture of the engine with the heat exchanger off of it. If you look closely at the interior of the rubber boot, you can see where the blow by was occurring. The tip on using non hardening gasket sealer at that junction is spot on. Anyone using these engines in a marine environment would be wise to take some preventive steps here.

I'll let you know what happens after the sea trials today.


John

[Strait Shooter]

Sorry, forgot to attach the pic last time...........I noticed another shortcoming on these engines. The 1/4" line that vents at the radiator cap is run down between the heat exchanger and block, only to vent into the bilge (and alongside the engine). Then when the engine cools it allows air to be sucked back into the heat exchanger? .....really?....... Bad engineer, bad bad engineer..........

I'm going to fix that as well.

The mixing of the antifreeze was on me I guess. But damn, you mean the yard boss didn't know that? So he's either very incompetent in his job, or is dishonest it would appear. Amazing.........

[delmarrey]

Jimbunyard,
A 49 YO tractor has all iron internal parts, I'm sure. Newer engines today use aluminum parts, in which e-glycol will eat the alum.

John,
On mine I took an over flow tank off a small car and attached that to the hose. It's funnny b/c the manual talks about keeping the overflow up to the mark but yanmar did not supply one.

[jimbunyard]

Delmarrey,
Not only that, it doesn't even have a water pump, the coolant circulates by convection. The radiator is bronze or brass though....

I'm gonna have to ask you to clarify that statement about ethylene glycol eating aluminum though. I've run it continually in my '94 Jeep, with an aluminum radiator, water pump and front timing cover, in my sailboat with an '95 (I think) MD2020 with an aluminum water pump, and my fishing boat with a TAMD41, with an aluminum t'stat hsg and probably water pump (can't remember), all with no problems.

I also checked the Volvo MD22 owner and service manuals (identical to the Perkins) to make sure they didn't specify a particular type of antifreeze before making any kind of statement about this (back in the middle of the thread), the only spec I could find was that the antifreeze should have anti-corrosion properties or alternately one could run just water with an anticorrosion additive. No mention at all of either ethylene or propylene.

[delmarrey]

In 2002 I bought a boat with a VW motor (pathfinders) that had some work done on the head just before I bought it, which had new green antifreeze in it. I put the boat on the hard for 1 yr & 6 months. Before I restarted the motor again. I noticed that the thermostat cover was wet and had lost its paint in that area. So I draind the antifreeze to replace the cover. When I did, a bunch of junk came out with the antifreeze.
In the mean time I not only had to replace the t-stat cover but another alum casting on the side. So I checked the water pump and its alum impeller was partially eaten away too, along with the hose nipple was about gone.

While searching and replacing parts the junk in the coolant had settled in its transparent containers (old window washing fluid bottles). I siphoned off the coolant and this grey milky sludge came off the bottom of the bottles. I rubbed it between my fingers and it was gritty and looked just like ground up alum.

I went to the VW dealers to buy a new water pump and they told me that it was a common mistake to use the wrong antifreeze. I bought their stuff for the install and it lasted 3 years until the next change. In which there was NO ill effects from the new coolant even though it was still siting on the hard 10 months out of the year. The motor lasted until 2009 and the VW coolant and alum parts were still in good shape when I pulled the motor.

And that's how I know the green chet ruins aluminum!

[Strait Shooter]

Quick follow up.

The flushing and cleaning of the heat exchanger, along with new thermostat, radiator cap, and some hoses, has turned my engine into the smooth running beastie I've come to know and love.

Under load the the temp raises to 192.
Without a load it stays at 182.

Much joy!

Im going to purchase an aluminum expansion/overflow tank from the race car world. I can get a real tall one with a site gauge on it, and locate it at the same level as the filler cap so that I'll always be able to check coolant easily as well.

I've learned a lot about my specific cooling systems. Thanks for all the help everyone.

I'm still not convinced about the e-glycol and aluminum issue. Someone with more brains than me can maybe explain it?

Thanks again.......

[a64pilot]

Ideal world your engine temp should always be close to the thermostat set point, if your exceeding that by much at all, you still have an issue, what temp thermostat do you have?.

Coolant expansion tanks don't have to be located at the same level, vacuum will pull coolant into the system if it's low, with an expansion tank, you should never need to remove the cap, one of the biggest advantages of an expansion tank is the system stays completely full, no air, no air means greatly lessened corrosion. I believe the cap for an expansion tank is different though, it needs a valve that opens when there is any vacuum so the liquid gets drawn into the system. Mount the expansion tank where it doesn't get shaken by the engine, I've seen coolant shaken out of half full tanks before.
When you replace the cap, make sure the pressure is the same as the old one.

I don't believe you can buy a modern anti-freeze that isn't aluminum safe, almost all modern engines are full of aluminum.

On edit, you will see different levels in your expansion tank with engine temp of course as liquids aren't compressible, but do expand with heat.

[Strait Shooter]

Originally Posted by a64pilot

Ideal world your engine temp should always be close to the thermostat set point, if your exceeding that by much at all, you still have an issue, what temp thermostat do you have?.

Coolant expansion tanks don't have to be located at the same level, vacuum will pull coolant into the system if it's low, with an expansion tank, you should never need to remove the cap, one of the biggest advantages of an expansion tank is the system stays completely full, no air, no air means greatly lessened corrosion. I believe the cap for an expansion tank is different though, it needs a valve that opens when there is any vacuum so the liquid gets drawn into the system. Mount the expansion tank where it doesn't get shaken by the engine, I've seen coolant shaken out of half full tanks before.
When you replace the cap, make sure the pressure is the same as the old one.

I don't believe you can buy a modern anti-freeze that isn't aluminum safe, almost all modern engines are full of aluminum.

On edit, you will see different levels in your expansion tank with engine temp of course as liquids aren't compressible, but do expand with heat.

The "start to open" temp range is 77/85c or 171/185f
The "fully open" temp range is 92-98c or 198/208f

I'm locating the expansion tank on a bulkhead, I'm locating it vertically so that the site glass on the expansion tank will be showing heat exchanger expansion tank level.

I've already replaced the cap with a matching psi one, but...... I'm getting ready to install two red dot type heaters in line with my Dickinson diesel stove, and the FW cooling system. When the system is complete, if the coolant won't raise to the best temp for the engine, I believe I can use a higher psi cap to raise the temp of the coolant without boiling it.

Yes, I have to agree that the e-glycol is aluminum safe. Was the only reason for the formulation of the orange antifreeze strictly a toxicity issue? Mixing it with the e-glycol really messed me up! Seems a silly thing for an industry to do....but what do I know?

[a64pilot]

Originally Posted by Strait Shooter

The "start to open" temp range is 77/85c or 171/185f
The "fully open" temp range is 92-98c or 198/208f

I'm locating the expansion tank on a bulkhead, I'm locating it vertically so that the site glass on the expansion tank will be showing heat exchanger expansion tank level.

I've already replaced the cap with a matching psi one, but...... I'm getting ready to install two red dot type heaters in line with my Dickinson diesel stove, and the FW cooling system. When the system is complete, if the coolant won't raise to the best temp for the engine, I believe I can use a higher psi cap to raise the temp of the coolant without boiling it.

Yes, I have to agree that the e-glycol is aluminum safe. Was the only reason for the formulation of the orange antifreeze strictly a toxicity issue? Mixing it with the e-glycol really messed me up! Seems a silly thing for an industry to do....but what do I know?

Your well withing thermostat limits, which of course means you have some reserve cooling capacity.

Boiling point and pressure are related of course, I don't know anything about those heaters though. Sounds like you asking if the heaters remove more heat than the engine is making, can the temp be raised by raising pressure?

You can't go by color of anti-freeze to determine chemical makeup and or compatibility unfortunately, and bad things can happen when mixing different chemistries, most likely your asking about Dex-Cool, which I think is organic acid based, I believe the intent was for a very long lived anti-freeze, and I've never had any trouble with it, but I've never mixed it with anything either. Wife's 05 CTS-V still has it in it, I need to do a fresh water flush and change just due to age.

Personally I drain and then remove the thermostat, open a drain and run the engine with the drain open while constantly filling it and run the engine until only clear water comes out, then drain and refill with new anti-freeze, I've seen real bad things happen from mixing the same color of anti-freeze before. I've seen green, yellow, red, orange and pink anti-freeze. Prius is the only pink I've seen

[a64pilot]

Apparently there is even a blue anti-freeze
http://www.eetcorp.com/antifreeze/Coolants_matrix.pdf

[jimbunyard]

Good to hear you got it fixed.

Those temps look good, diesels are generally more efficient when they're running near the hot side of their normal range.

On the ethylene/propylene question, as far as I know the main reason for the change was toxicity. Regarding ethylene and aluminum, the problem was (and remains) heavily mineralized water creating either overly acidic or basic conditions, either of which are corrosive to metals. The addition of heat generally speeds the reaction. Some aluminum alloys are more susceptible to this corrosion than others, which may be why some manufacturers specify specific types of coolant.

As far as I could find, there were no specific coolant recommendations for your engine, other than using one with anticorrosion additives, so with distilled water, you'll be fine with ethylene glycol if you want to use it.

[Strait Shooter]

Originally Posted by jimbunyard

Good to hear you got it fixed.

Those temps look good, diesels are generally more efficient when they're running near the hot side of their normal range.

As far as I could find, there were no specific coolant recommendations for your engine, other than using one with anticorrosion additives, so with distilled water, you'll be fine with ethylene glycol if you want to use it.

Yes, these temps will work. Thanks for your help, it was much appreciated. It would appear I'm on the low side of the temperature curve. Any opinion on the radiator cap pressure/temperature conjecture?

Yes, strictly distilled water. After researching the various antifreezes, I've decided to go with the ethylene glycol.
I like the yearly flushing routine and will begin it now also. Is there any reason that I can't, or shouldn't install a SS shut off valve where the drain plug is?

[jimbunyard]

I suppose the most important thing to realize and remember is that the
cooling system is dynamic and operates within a variable set of environmental conditions. If the raw water is at 45F and the ambient temp is at 90F the engine operating temp, even with all other factors controlled for, will be different than if those two values are reversed. The main reason for the t'stat is to keep the engine operating at as close to a specific temperature as possible.

I didn't mean to give the wrong impression; given the time of year (if you're in the Pacific Northwest), I'd say the temperatures you're running at are at the upper end, in the summer they'll almost certainly run hotter. As A64 says, consider it a little reserve cooling capacity.

As for increasing the operating temperature of the engine there are two sure ways; increasing the load and changing the temperature rating of the t'stat. I would strongly recommend against going to a hotter t'stat, efficiency is one thing, running on the ragged edge between efficiency and overheating is quite another. Increasing the pressure rating on the cap will increase the boiling point of the coolant, but unless the transfer or production of heat within the engine is changed, the operating temperature will remain the same.

If the heaters you plan to install use engine coolant to heat them, I would expect them to make a difference in the engine operating temp, how much depends on the heaters efficiency. It is conceivable that you'd have to change the t'stat to compensate and if so the radiator cap too, but I'd be very leery. My experience with aluminum head engines is that they don't like overheating, so a comfortable temperature cushion is prudent. Better some kind of volume modulating valve (if the heaters don't already have one) and an extra sweater....

Can't imagine any problem (other than forgetting to close them) with a drain valve instead of a plug, I've got 1/4" ball valves on the block, the exhaust riser and the muffler.