How much water is ok?

[paulfarber]

Anyone have any idea how much water is acceptable to run in diesel?

With condensation, unknown tank sources (are there really filters in the fuel lines? Anyone ever see one get changed?) etc a lot of water has to be getting through.

I read

http://www.steelsoldiers.com/deuce/1149-fuel-filters-additives-water-fuel-bacteria-etc.html

But its pretty vague.

Any ideas? I have yet to see any significant water in when I drained my primary filter.

BIODIESEL measures water in PPM to pass ASTM standards.... does it really have to be that low??

 

[gimpyrobb]

I know when my truck wouldn't start one day, I drained 7gals of water out of the fuel tank. Dumped out filter cans and put in new filters. Let it sit over night and it started up and ran great the next day. Less water is better than more water. I have also been told that water injected into a running motor will destroy the injector.

 

[Chief_919]

I have also been told that water injected into a running motor will destroy the injector.

Water will destroy an IP or injector quickly.

When the injector or plunger in the IP compresses the fuel it does it very quickly. Mix in water and under the pressure and heat the water will flash to steam. Steam + no lubrication, no "cushion" and the will quickly destroy your fuel system parts.

 

[Capt.Marion]

Water also doesn't compress, which is bad news in a piston-injector pump that is attempting to compress and pressurize a liquid up to 1,400 psi.


EDIT: This statement probably isn't 100% correct. Please feel free to correct me.

 

[Chief_919]

Water also doesn't compress, which is bad news in a piston-injector pump that is attempting to compress and pressurize a liquid up to 1,400 psi.


EDIT: This statement probably isn't 100% correct. Please feel free to correct me.

Fuel doesn't compress either.

It is when the water flashes to steam, and the steam does compress, that things get screwed up fast.

 

[stumps]

In a hydraulic system, like a backhoe's, water is really bad because it is much thinner than the hydraulic oil, and droplets entrained in the oil go rocketing past the seats on the control valves, and take a bit of seat material (usually steel) along with them... think: water jet cutting machine.

I would think that much the same thing happens when the water goes past the valve seat in the injector nozzle, and through the nozzle holes itself. Erosion is not a good thing in a nozzle.

Gasoline boils between 100F and 250F, starting much lower than water, and yet the designers of the MF engines talk about it flowing as a stream through the injector and into the combustion chamber... I think the injectors are cooled enough by the block and the fuel to prevent flash boiling.... but I am not sure of this at all.

-Chuck

 

[wreckerman893]

An old school diesel mechanic once told me that if water got past the IP it could cause the tip of the fuel injector to blow off (the steam thing) and inject unatomized fuel into the cylinder....this often results in a hole being melted into the piston.

I had it happen to a 400 Cummins in a Peterbuilt I was driving.....the piston had a hole the size of my little finger in it.

 

[Floridianson]

pressurize a liquid up to 1,400 psi.
EDIT: This statement probably isn't 100% correct. Please feel free to correct me.

3000 psi

 

[cranetruck]

Go for zero tolerance.
Alcohol will mix with water and may render small amounts of water harmless (one side effect of homemade biodiesel that may have some residue of methanol).
Drain water trap/filters often.

 

[stumps]

An old school diesel mechanic once told me that if water got past the IP it could cause the tip of the fuel injector to blow off (the steam thing)...

Interesting...

I spent about 2 hours last night trying to get to the root of the water in fuel issue as it applies to C-I engines, and I came up with "theories" that traveled in two different directions:

The fuel additive companies (Stanadyne, etal), and the engineering textbooks on my shelf, all seemed to be interested in the abrasive qualities of water in the 10 to 40 micron particle size range, and the corrosive properties of water in general, and the hear-say group (not meant derisively: my buddy the mechanic, this chief I knew, somebody once told me...) seemed to like the idea that water blew the tips off of injectors.

Everyone likes stories of explosions, so I guess exploding injector tips fit in that category.

The "fuel experts" (additive companies...) concentrated on corrosion caused by free water droplets, water's (in quantity) ability to stop an engine dead by preventing fuel from getting into the cylinder, and water's abrasive qualities when the droplets are the right size, and under hydraulic system pressures. Their cure to water was to fracture the water droplets to such a small size that they are no longer abrasive, and will pass out the tailpipe as steam.

As to the hear-say group's conjecture that water blows the tips off of the injectors:

We all have quite a bit of experience with water and steam, whether we know it or not. The pressure cooker your mother used demonstrated an interesting property of water and steam and that is it will increase in temperature when you allow it to increase in pressure... that is to say that if you keep water under pressure, the temperature needed to turn it into steam will increase greatly.

A fuel injector nozzle has a valve in it that is designed to hold the nozzle shut until the pressure rises to the pop-off pressure where the valve spontaneously opens, and then as the pressure again drops, it will seal off the nozzle (to prevent drips...). If steam were to form in the injector, it would simply cause the valve to pop-open and release the pressure.... right?

In any case, my study did quite a lot to enforce my belief that the only problems with water in your fuel are corrosion, abrasion, and possibly the complete elimination of combustion (all water).

-Chuck

 

[paulfarber]

I also am on the 'a little water won't kill you' side. I mean one way to clean the combustion chamber of an internal combustion engine is to pout water into it. High compression multi thousand HP v12 engines of WWII fame had was was caused 'WAR POWER' aka water injection to improve performance. Lots of hot rods also use water for a quick performance boot.

7 gallons will drown you

I just wanted to see what some realistic expectations were becuase I am simply not getting this perfect, water free used oil for free, and will have to deal with water (free or emulsified) and want to establish some limits.

Yes, I let it stand, and suck out the water as it accumulates, and will try to set up a drying method of some sorts.

 

[swbradley1]

Anyone have any idea how much water is acceptable to run in diesel?

3.7 ounces

 

[Chief_919]

I also am on the 'a little water won't kill you' side. I mean one way to clean the combustion chamber of an internal combustion engine is to pout water into it. High compression multi thousand HP v12 engines of WWII fame had was was caused 'WAR POWER' aka water injection to improve performance. Lots of hot rods also use water for a quick performance boot.

7 gallons will drown you

I just wanted to see what some realistic expectations were becuase I am simply not getting this perfect, water free used oil for free, and will have to deal with water (free or emulsified) and want to establish some limits.

Yes, I let it stand, and suck out the water as it accumulates, and will try to set up a drying method of some sorts.

Water in the manifold is not the same as water in the fuel system. You can get water injection for a 6.5 and it will improve power and lower EGT's. But inject that exact same amount of water into the fuel just before the IP and your result will not be the same...

 

[emr]

In my cckw 352 the head gasket blew and the water / glycol mix was running right out the exhaust in a flow , she was still purring like a kitten though man thats a real truck just an fyi... I know its not a diesel . but was pretty cool to see, for the moment....

 

[paulfarber]

Water in the manifold is not the same as water in the fuel system. You can get water injection for a 6.5 and it will improve power and lower EGT's. But inject that exact same amount of water into the fuel just before the IP and your result will not be the same...

Please explain?

Is it the water going through the IP and injector that is the concern? The water would be under several thousand PSI, that would INCREASE its boiling point. I found a dubious answer that 3psi will raise the boiling point of water 1F (this is true).

I don't know if the rapid expansion of this water is the real culprit (some have alluded to injector damage) but how can the steam (well, the pressure would actually be a massive decrease from the injector to the less pressurized cylinder) be that explosive? The fuel is also atomizing at this rate.

Is water that abrasive? The fuel would also have the same particulates in it.

 

[stumps]

Please explain?

Is it the water going through the IP and injector that is the concern? The water would be under several thousand PSI, that would INCREASE its boiling point. I found a dubious answer that 3psi will raise the boiling point of water 1F (this is true).

I don't know if the rapid expansion of this water is the real culprit (some have alluded to injector damage) but how can the steam (well, the pressure would actually be a massive decrease from the injector to the less pressurized cylinder) be that explosive? The fuel is also atomizing at this rate.

Is water that abrasive? The fuel would also have the same particulates in it.

Yes, water is that abrasive. It is so abrasive that high pressure streams of water are used to cut through steel plate. The water jets for doing this are made from special ceramic, sapphire, or even diamond, depending on the jet size and application.

A little research on your part should point you to information about what entrained water does to the spool valves on hydraulic equipment (backhoes, dozers...).

-Chuck

 

[swbradley1]

Isn't abrasives added to the water though? My Brother has one in their shop where he works. It is mixed into the water in order to cut through the steel.

I just saw it two weeks ago and saw the containers that are mixed with the water.

 

[paulfarber]

Yes, water is that abrasive. It is so abrasive that high pressure streams of water are used to cut through steel plate. The water jets for doing this are made from special ceramic, sapphire, or even diamond, depending on the jet size and application.

A little research on your part should point you to information about what entrained water does to the spool valves on hydraulic equipment (backhoes, dozers...).

-Chuck

Yeah.. as posted above a little research would have helped you. Water jets cut because of the cutting grit.

Stop inflaming. Start participating.

 

[stumps]

Yeah.. as posted above a little research would have helped you. Water jets cut because of the cutting grit.

Stop inflaming. Start participating.

Adding abrasive improves the performance of a water jet cutter (at a lower pressure), but a high pressure water jet will cut steel without any added abrasive.... it is all a matter of speed.

Water in high pressure hydraulic systems (like an IP) is abrasive whether or not you choose to believe it. My researching the subject found that folks like Stanadyne determined water particle sizes around 1 micron are ok, but water particles in the 10 to 40 micron range are very damaging.

If my calmly, and unemotionally, presenting the results of my researching the issue is not participating, and seems inflamatory to you, I guess I just don't know what to say. I think, however, that your judging it that way says a lot more about you than it does about me.

-Chuck

 

[swbradley1]

Looked like participation to me..........

HowStuffWorks "How can water cut through steel?"

When I worked in machine shops around the region for 11 years I had just never seen a water only cutter. Probably because most of the work in this area is tooling and water only is for softer materials.

I'm surprised that water molecules would have different sizes. I figured a molecule of any material is of a consistent size. Maybe that contributes to water being abrasive in the injectors?