OK its time for the great fluid change......

[RICHARDG]

One last thing from me on this,,whats the name of the additive,what do I ask for,,doubt if I can even find it here at my local stores no matter what it is called,,but I get out every now and then,and I'll try and find it,,,,thingy

 

[Harrygoodwrench]

You could buy the Ford DCA (diesel coolant additive) at the dealer or any parts place that deals with heavy equipment should stock it. Your average "Auto Zone" type store may not even know what you want. Nothing against Auto Zone or nothing its just mainly car stuff they do. I think my bottle was 32 ounces and not 16. Instructions tell how much to add. I approximated 3 ounces. Like I said, it may not even be necessary on these small diesels but can't hurt any as the other ingredents also help too.
Always great conversing with Richard. /forums/images/graemlins/wink.gif

for your reading and consideration of choice.
http://www.shopdiesel.com/index.cfm/action/coolantfaq.htm

 

[bluechip]

Hmmm. THis is interesting. As I understand it, the Chinese don't even use antifreeze, much less anti cavitation additives. Ill go with the concensus though that it cant hurt. I don't thinkg the coolant flows quite as fast in our engines as in modern design truck engines though...

 

[JohnS]

Harry,

Thanks for the explaination. A couple things still struggling with. On our faucets, most of the air bubbles are from the screen or other arritation method. It is designed to add air into the water. Remove that from your faucet, and most air bubbles are from disolved gases. Some from direct contact with the air. For air bubbles from turbulance, you need trapped air to mix with the water. I would think there is only minimum trapped air in our engines. Using distilled water, should prevent disolved gases. Also, don't understand why this is an issue in diesels vs gas engines, given this explaination.

Now, on cavitation caused air bubbles, like on a prop, they are caused by a very high pressure zone on a particular area of the prop. They will quickly, disappear (implode?), once they leave the high pressure area. When they do implode on the surface of the prop, they do cause pitting. (info from boating forums)

Now, I could see that a pump impellor might have cavitation on some of the impeller blades, but don't know if they would reach the cylinders before imploding. Since the anti-freeze is under slight pressure, maybe they don't immediatly implode???

OK, now I going into the pure "speculation zone". Given that it has been stated that the rubber hoses on our tractors, don't like our anti-freeze, and deteriate quickly, isn't it conceivable that the rubber o-rings in a wet sleaved engine, might not like it either?

Anyway, still a bit of a mystery for me, but will continue to use the Fleet charge, just in case.

 

[GRUMPA]

I dont mean to sound like a smarty pants here but isnt water also called H20(cant make the little 2) meaning 2 parts hydrogen and 1 part oxygen. /forums/images/graemlins/confused.gif

 

[JohnS]

Yes, but seperating the atoms, you would then have two hydrogen atoms as well. As far as I know, the only way to seperate the atoms, is via electrolysis. Now, if we had a bunch of hydrogen and oxygen gas forming within our engines, add a little spark, and will give another meaning to "blown" engine. /forums/images/graemlins/laugh.gif

 

[ToolManRick]

Okay, gotta add my 2 penny's worth too. From my old boating days.. cavitation is the boiling of the water caused by the lower pressure on the "suction" side of the prop. Much the same as water boils at a much lower temperature on a mountain than at sea level. The prop, pulling the water into the blades at too high a rate can actually lower the pressure to the point where the water begins to vaproize. A cavitating prop is very inefficient since it built to pull itself through water, not vapor.

As for the additives, can't hurt. Pretty sure mine just has plain old antifreeze in it and a definite yes on using distilled water. The minerals can raise havoc on the ph level, partically on todays radiators with aluminum cores. Plain old tap water will eat right through the aluminum on no time.

 

[mark1]

WOW! looks like I really started something bringing up the subject of the antifreeze additive!.Really I don't work for the company that makes it!(wish I did!) Now do I bring up the subject about "low sulphur"gear oil??and yellow metals?? /forums/images/graemlins/wink.gif

 

[JohnS]

Rick,

You could be very well correct, that it is the low pressure side vs high. Not sure if it changes the discussion much, just which side of the blade they are formed on.

It is seperate and different from the mis-labeled anti-cavitation plate, found on outboards and I/Os. This just prevents air from being sucked down into the prop, from the surface.

 

[Soundguy]

</font><font color="blue" class="small">( cavitation is the boiling of the water caused by the lower pressure on the "suction" side of the prop )</font>

It lowers the vapor pressure.

Soundguy

 

[Brad_Blazer]

You guys are starting to get it right. Cavitation occurs when a low pressure area causes the pressure to drop below the saturation pressure (boiling point) of a liquid forming a pocket of vapor. When the resultant bubble moves out of the low pressure area, it collapses or implodes. Since liquids are incompressible and you have momentum filling the void from all directions, the result is a tiny area of extremely high pressure. When this occurs against the wall of a vessel, it will cause erosion. This is very common in pump impellers and in piping systems where the plumber neglects to ream the pipe ends. In a hot system like a cooling system, the water is already close to the saturation point so cavitation is easy to initiate. In a diesel, there is a lot of knocking vibration due to the high pressure combustion. Those vibrations translate into pressure waves in the coolant and may very well cause cavitation, especially adjacent to the cylinder walls where all of that noise is initiated. I have no direct experience with diesels but I do know that cavitation can be a concern in any fluid system that operates near the saturation point or at low pressure (it only takes -15psig to pull a perfect vacuum.)

One way to prevent cavitation is to remove nucleation /forums/images/graemlins/confused.gif sites. A nucleation site is a small crevice that holds a pocket of air. For a bubble to form, it has to overcome surface tension (intermolecular attraction). When the bubble radius is very small, suface tension is very effective at resisting cavitation. (force = pressure x area and area is small) At a nucleation site, the trapped air provides a big enough radius for cavitation to occur. An additive may work by coating or wetting the surfaces to eliminate nucleation sites. As an example, try this experiment: Partially fill a small pan with cooking oil, then add a few drops of water. The oil should be just deep enough to cover the water and prevent a free water surface on top. Put the pan on a hot burner and watch the drops closely. The temperature of the oil and water will increase way past the saturation point, then the water will evaporate explosively causing you to curse /forums/images/graemlins/shocked.gif when your face gets burned. Actually, I did this experiment many times before I had any clue as to the mechanism at work - maybe you have too. /forums/images/graemlins/grin.gif

Hope that makes sense,
Brad