Hold on! i need to get another bag of popcorn.

 

It is exactly what SpringerPop posted.








But I am still interested in the point your brought up about the wet sleeves.

 

Kajtek:
While I realize that you are very solid about where you stand I will give you a bit more information on the reasoning behind cavitation since it seems as though you may not believe it is actually happening. First, if you are familiar with phase behavior graphs, in particular the pressure temperature graph, then you will realize one important fact. If you have an engine at operating temperature, then for a given number of combustion cycles, the engine will exhibit isothermal conditions close enough to plot on a PT diagram. You will (hopefully) agree with me that the pressure in the cylinders is dependent on the compression ratio of an engine, and that a diesel engine has a high compression ratio. You will also agree that there is a sudden pressure spike in the cylinder when fuel is injected and the cylinder is firing properly right? Good. If you have an elastic material and are within the restoration region where permanent deformation has not taken place, then the cylinder pressure spike will decrease rapidly as the piston travels down bore. Given the elasticity of steel, the cylinder walls will flex outward and then inward slightly as the pressure spike is alleviated. So now we can move onto the PT diagram. If you plot the pressures experienced with a given temperature, you will find that pressures in the localized region around the cylinder jacket drop low enough to allow vapor to form while the cylinder wall is contracting. This 'bubble' that is formed suddenly goes back to liquid phase when the coolant in surrounding areas fill in the void space. The sudden phase change is capable of removing material from cylinder liners, and water passages. Are you familiar with bernoullis principle as well? Then you will realize that the venturi effect also conributes to cavitation as well. Areas of reduced pressure allow for cavitation as well because the fluid is closer to the bubble point line as compared to areas of higher pressure.

So, returning to your other statement about the old mercedes diesels. 1. What is the compression ratio of the engine in question. Obviously, the compression ratio largely determines the effects of cavitation/eriosion. 2. what is the thickness of the cylinder walls of this mercedes? The thinner the walls, the more flexure is shown during the combustion process and rebound of cylinder walls. 3. What is the pressure of the coolant system in good specs? 4. Did you use prediluted antifreeze, or did you dilute with water? What kind of water? Tap water? You may feel these questions are unimportant, but they are determinant of whether cavitation occurs.



Quick444:
Wet liners means the cylinder is actually a liner that is removable for rebuild allowing for original specs to be maintained. The other method for constructing an engine is using parent bore, which means the cylinder is bored directly into the block, rather than a liner being used.

 

Popcorn is overrated. Nothing better than good beer and chunks of smoked kielbasa.
WATCH AND LEARN
In the links provided by Alex (good find) a member who is highly qualified in coolants engineer brings additional issue
Meaning Pop adding SCA to his system might give it questionable protection, but running the system without filter is actually grinding it with hard buildups.

BTW Alex you pointed the requirements about adding the shoot of SCA to new coolant. There is nothing about monitoring.

 

Great, now I want smoked brisket haha.

 

Thanks for the explanation.


So if the PS doesn't have wet sleeves wouldn't that increase the importance of something like cavitation?

 

Well, it is hard to say. I know the importance of SCA/DCA is high, but is it higher with a parent bore vs. a wet sleeved engine? I would be more concerned about cylinder wall thickness. There was an IDI that someone had measured the movement of the cylinder wall and had seen 0.004" change if I remember correctly. The next question is, well why don't they make a cylinder with wall thick enough to resist all movement thus eliminating cavitiation. As long as you are within the elastic region of a material, you don't necessarily need to add material thickness. This would add unneccesary weight and possibly reduce the cooling capability of the system. The specific heat of cast iron is around 1/10th that of water. The thicker the cast iron, the longer it will take to cool it down.

 

While looking around I can't find anything about the monitoring. Kajtek is right on that.

I think the confusion here is over whether they should be monitored vs needed at all. Maybe that was the problem in the first place.

Ford does recommend adding it in at certain intervals and adjusting based on severe use but nothing about actually checking the levels.

I think that was a concept I picked up from the forum since I have used it (and its been a huge help) since I bought my truck about a year ago.

I don't monitor mine but I switched to ELC stuff right away for fear that it was uber important.

 

Do you do a UOA or just change your oil. People test coolant so they don't need to replace something which may still have a little life left. The importance of keeping the additive within a window of acceptable concentration is high. Just like changing your oil, you can just replace the additive. OR you can test the coolant and see if it has gone through the additives. Just in the same, you can test your oil or just replace it.

 

Than there is the "dark side" of the issue. I partly quoted it above, but my understanding is, that Ford annual coolant changes are not only due to prepacking them with SCA at the time, but also due to flushing the mineral buildups that can grind the pump and the passages.
Meaning extending the interval with correct SCA brings danger of damaging the system with mechanical dirt.
Just as a comparison -new (6 years) Mercedes diesels have a (secret) chem pack build-into the coolant reservoir. The coolant change intervals are .... ready? ... 15 years. Still no SCA monitoring required.

 

The severe duty schedule indicates replacing coolant due to additive depletion at one year intervals, but normal service has a longer interval which would arguably cause this 'grit' to still be in place. SO, while yes the presence of grit in your coolant is a possible problem, I would be more worried about the additive strength than grit. Even with a filter, the grit may not be completely removed with a bypass filter if you change your coolant yearly. Then you change your coolant and you reintroduce grit. Use tap water and the likelihood of problems increases. But the question is not about silicate dropout, but rather cavitation.

I believe the OP's thread has kind of been taken off course.

 

Ain't that beautiful?

Than OP has a problem with leaky pump.
Wouldn't that indicate grit problem?

 

Possibly, but it could be a seal which has cracked due to heat cycling, could be a failed seal due to exterior contamination, could be a failed seal due to using tap water. The possibilities are really endless. My water pump bearings failed at over 200,000 miles. I didn't notice a huge solids content in my catch pan. Didn't filter it too finely, but nonetheless, I didn't have a huge problem with grit. BUT, with that we introduce a difference in coolant formulations.

 

No, but I do carry a $1m umbrella policy and when I had green coolant I monitored SCA's based on the direction of 2 local ford dealerships. I also bought my test strips from my ford dealer.....if sca monitoring is not an issue why do they carry test strips?

 

You didn't read the whole topic, did you?
There are engines where monitoring SCA ane replacing the precharged filters is pretty critical.
Just our PowerStroke are not one of them.