Water Injection for cleaning

[GregMN]

After reading the "Cheap Water Injection" thread I searched and read everything that came up under "water injection" on this forum. http://www.peachparts.com/shopforum/diesel-discussion/313125-cheap-water-injection.html
It seems to me that there are 3 reasons for WI:
1: water or water/methanol to increase power
2: to lower combustion chamber temperature
3: to clean carbon from the combustion chamber and the piston rings.

In my mind 1 & 2 are about power and the 3rd is about maintenance or repair.

I am looking at WI for it's cleaning effect. I run WVO. I have had no WVO associated problems with my cars (see signature info). But, some of my friends have followed me down this path with less success. I ended up with one of their cars. When I got the pistons out, I had to chisel the rings out their grooves. Another's engine is showing signs of blow by and I want to see if WI will help that engine. A well designed WVO system still has a weak link; and we have found that to be the operator.

Would a WI system design be different for power than for cleaning ?

I have read that the water must be misted at high pressure. (I believe the person used the term "atomized", but we are not really breaking the water down to the atom level with a high pressure sprayer.)

I have read that any stream of water introduced into the intake air stream at any air flow rate above idle will be "mixed" with the air enough to do the job.

Is there a water to air ratio that is too little to do any good (just high humidity) or too much as to cause harm (hydro-lock) ?

Does anyone have any evidence that WI can free up carbon stuck rings.
Like before and after compression tests ?
Before and after crankcase pressure readings ?
Before and after blow by felt out the oil filler ?

[GregMN]

1995 E300D, 606 n/a engine, about 225k.

It has been running WVO for a couple of years. This car was blowing the dipstick out and spewing oil out the tube whenever the engine was under heavy load above 2500 rpm. This was becoming a regular occurrence that could be repeated at will. It was also becoming hard to start with a very lumpy idle until warmed up.

We installed one of the nozzles "pdrayton" used in his "cheap water injection" system in the air hose from the top of the air cleaner box to the crossover pipe. Since this is not a turbo motor there was no intake pressure to overcome so the washer fluid pump provided plenty of pressure ( it maxed out a 30psi gauge when I tested it). A driver controlled switch was installed. The pump was turned on when the engine was warmed up and at 2500 rpm or above. After 4 gallons of water were run through it, the dipstick will not blow out no mater how hard we try, and the car starts easy and idles smoothly from cold.


1986 603 in a 380SEC

This engine had new rings installed and the cylinders honed before being installed in the SEC. During the break-in drives it didn't seem to have much power. I thought it was due to the 2.47 diff. After about 400 miles the rings still had not seated and the engine was burning a quart of oil in about 125 miles. I don't remember what lead me to do it, but I removed the ALDA. I spun the tires pulling out of the garage. So I was only getting the fuel for a n/a engine but still had a parasitic turbo restricting the exhaust. I drove it another 100+ miles and it used another quart of oil.

I had an extra crossover pipe, so I installed a nozzle in it and used a 50psi water pump from a motor home. I turn it on when the engine is warmed up and at hwy speeds. I ran about 8 gallons through it over 200 miles. The oil consumption is down significantly (down 80%) and should continue to fall as the rings continue to wear in. Did the extra pressure in the cylinders caused by the water injection cause the rings to start to wear in? Would the rings have warn in if I did nothing but drive it the additional 200 miles without water injection but with the ALDA removed ?

1987 603 in a 350SDL

This engine has about 275k. It has run WVO for about 45k. I ran about 4 gallons of water through it. Since there was nothing really wrong with it before, it's kind of hard to say if any good was done by it. I did get it to blow out some soot under heavy load and high rpm. It seems to start a little easier and initial idle may be a bit smoother but it's all very subjective.

[Pants]

Interesting empirical data, Greg. Anything new since those days?

I'm just starting to run various blends of WVO - can't do 100% without extreme starting problems, even in my tropical climate, and with injector line heaters...

--Dave