big oops found tonight

[betterthanstock]

Water is already the burnt product of hydrogen and oxygen. Adding water quenches the flame, and is used as a band aid in ridiculously overfueled engines to prevent meltdown, but the water never adds energy to the combustion. The steam does add pressure, but it takes combustion energy (fuel) to produce steam. All air already contains steam (relative humidity).



The steam may "steam clean" the oil film from the cylinder walls though.



Now, if there was a way to inject water to the underside, or inside of the piston, that would cool it a lot better than oil.



I think ceramic coated pistons would have survived this situation, and would not have dilated as much. If the scuffing was only caused by expansion, it would have been fine, but if it was caused by "steam cleaning" of the oil film, then some scuffing would still have occurred.

 

[Jim Fulmer]

A guy called me last night with a bone stock 04' that tows with 150K on the clock. The truck has a rattling noise from the back to the motor with white smoke, never clears up ect. I was thinking injector, nope they have been changed, then I was thinking bad valve, if it were me I would spend about an hour checking stuff then pull the head for a look... ... opinions!



Jim

 

[Bandit1]

that was our first approach on this motor, was to go through all the obvious stuff, then progressivly got more involved (pulled head, found burnt piston, scuffed cylinders, and smooth cylinder walls) start small and work your way to more involved work.

 

[bzingre]

First off, lookup Thermolysis and how it pertains to breaking water down to get the hygrogen (highly flammable) out. After you get done with that, research the temps and pressure in a diesel engine under load, the vapor curve of water, then get back to me.





Second, compression, or compression ratio as they are essentially the same thing, is the relationship of volume of a cylinder with piston at BDC to the same cylinder at TDC. It is a mechanical factor based on the construction of the engine. YOU CANNOT CHANGE COMPRESSION BY INJECTING WATER!!!



The ONLY thing injecting water does is change the density of the air charge. Change the density of the air charge changes combustion temps. IF your water injection is working correctly the combustion flame can actually burn hotter with less overall EGT's.



Water injected in a fine stream into a 300 degree plus air charge then compressed at 17 to 1 is NOT going to be liquid at at a pre-injection temp 700 C. It will be vapor which is compressible and once again all it is doing is changing the density of the air charge. The denser the charge the more heat that is needed to raise the temp.



From just the pretty pictures that were posted there is no way to know for sure what happened. The 1500 degree temp is not too much if it is for a short time in the combustion cycle, but, advance the timing too much and the 1500 is too much. The only thing that is a given is it was TOO HOT for TOO LONG and spraying water on it did not help.

2500C = 4532F = 2770K Doesn't get that hot in the cylinder. Steel starts to melt at 1300C or 2500F. Alloys for pistons still do not increase melting point to 2500C.



Depending on year, peak cylinder pressure = 2100-2900PSI



Thermolysis = When water or steam is heated to 3000K, hydrogen and oxygen in the water can be decomposed. This method can produce hydrogen in high efficiency of which high temperature.

 

[cerberusiam]

Water is already the burnt product of hydrogen and oxygen

Water is the byproduct of some chemical transformations, but, water is composed of 2 hydrogen molecules and 1 oxygen hence the chemical symbol H2O. Crack the water and you get free hydrogen which is flammable and free oxygen which is an oxidizer. With a heat source present the hydrogen burns and oxygen provides the needed oxidizer. Yes, you will have water condensing out after a combustion event but not until well down the exhaust path due to the EGT's. However, too much water will quench the combustion and leave too much vapor present and cause issues.

2500C = 4532F = 2770K Doesn't get that hot in the cylinder. Steel starts to melt at 1300C or 2500F. Alloys for pistons still do not increase melting point to 2500C.

Sure it does, at least thats what the thermal imaging is suggesting. You need to remember that EGT's are only a representation of a third of the energy created in a combustion event. A third is used up in providing the power to turn the crank and a third is siphoned off by the cooling system. The other thing to understand is only the hottest part of the flame front is at these temps and the whole chamber is not burning. There is only the injection paths of the diesel that are getting this hot. The rest of the content is much cooler. At these high temp areas the water is breaking down into its base components. This is why timing is so critical when these temps are reached. If the time span is short enough the surrounding metals do not have enough time to absorb the heat. Extend the burn time too much and everything heat soaks and THEN the problems begin. EGT's that are relatively safe for short periods become extremely destructive when the time period is extended irregardless of water injection. I suspect that may very well be the root cause of this and other engine failures with power adders.

This leads one to believe it is better to inject water ouside the cylinder before it gets past a closed valve but after it is heated by the intake compressor.



If it is injected directly to the cylinder the decision as to how much air (Oxy) has been drawn in and hence avail for combustion has already been made.

It really depends on what is trying to be accomplished. Indirect injection spreads the water thru the whole air charge and essentially just increases the density. Very little is at the hottest part of the flame front where it can be used for other puposes. The same effect can be accomplished with compound twins, NOS, etc. We are trying to correct a stoichiometric imbalance and bring the combustion parameters back into line.



Direct injection puts the water at the hottest part of the event and adds to the density change the ability to advance timing without creating emissions. It allows the flame to burn hotter and longer to eliminate soot from cool incomplete burns and eliminate the NOX emissions that come from higher temps. Typical setups run a little to the stoichiometric lean to eliminate NOX at the expense of power and soot creation. By using injected water the emissions problems can be addressed with the benefit of added power from the complete combustion of the fuel.





Unfortunately, like anything else that may a boon for the customer it will not happen until it is legislated thru EPA regs AND the public demands it with their buying dollars. Somebody has to pay for the R&D and that is the premium we are paying for diesel and these trucks cuz the automakers WILL NOT do it out of the kindness of their hearts. Its all about the bottom line and ROI.

 

[bzingre]

Sounds like you have your stuff together. Do you work for an engine manufacture or something? I agree with your statements, but thermal imaging of most flame fronts I have viewed suggest peak temperatures allowing water to break down into constituents only occurs at pin point areas of the combustion "bowl" allowing thermolysis to occur only if the water contacts these "hot spots. " I don't even have a guess, but the amount of actual hydrogen gas burned during water injection on a pulling truck is most likely very small and probably does not register as measurable contributor to the increase in power gained by the other effects. OK, maybe I do have a guess that 99% of the water does act to increase the charge density and cool the burn and only a small amount "burns". I don’t find much data to support the technology.

 

[rattlbox]

stopped by lloyds to look at carnage on this motor and its bad.

 

[cerberusiam]

Do you work for an engine manufacture or something?

Nah, I design financial systems on buggy software. Don't get to do the FUN stuff. :-laf



At some point in the power curve there may be enough gain in power from cracking the water to negate the loss due to changes in charge density but it is a very narrow window. All things being equal and close to stoichiometric balance there is probably a slight loss when injecting water. The over fueled scenarios is where it is a great benefit. Now if we mix methanol with the water we introduce a whole new scenario that provides multiple benefits.

 

[MAshley]

So on a stock truck, ... ... Do I have to worry about any of this? I have no gages, but I do haul heavy... just under 26K lbs. 06 with 6sp if it matters.

 

[cojhl2]

So on a stock truck, ... ... Do I have to worry about any of this? I have no gages, but I do haul heavy... just under 26K lbs. 06 with 6sp if it matters.

Here is what I think, take ir for what it's worth.



Some say with these oil cooled pistons and a stock system you can't hurt the engine.



I don't agree, I think you need to be careful when pulling those big loads in hilly country especially. You must watch the water temp but better watch the exhaust gas temp if you are equipt to do so.

 

[lmills]

Here's what I think when I hear the phrase, "twins cost too much. " If people would set back and look at the cost that some are paying for cool air, they would not be too far away form twins. Now I know hardly anyone pays retail , but then again if you shop around you can get twins cheaper in certain places also. An example:



Big turbo (66 or silver bullet)----$1600-2000

Afe stage 2 --------------------$425-475

CFM/Banks intake---------------$400

Innercooler---------------------$1000



And it doesn't take long to add up. Now, as I mentioned, I know this is not everyone that does this, but I have seen it a lot. Guys will buy a big single then drop all kinds of cash trying to keep things cool while trying to use the HP they have.



I am willing to give up the little bit of space in my engine compartment as a trade off to having reliable HP. Not to mention the $6-8K that this guy is going to end up paying to have his engine rebuilt from the "savings" he had from not buying enough air flow for his excessive fuel. Do what you want, if a single is all that you feel you need, maybe so but I would cover all the bases and not just the initial cost.

 

[WWildbore]

Lloyd, what turbos do you have and approx. how much invested?



wayne

 

[lmills]

2500 invested in an HX40/HT3B kit with stock innercooler and stock intake manifold

 

[BSwope]

Me needs a set! me needs a set! Now if i can talk the boss into havein twins! :-laf Lloyd i thought third gens wont light twins! :-laf

 

[WWildbore]

Is the HX40 the stock turbo that came on the truck? Who makes the HT3B and what is a comparable turbo size.



wayne

 

[lmills]

Me needs a set! me needs a set! Now if i can talk the boss into havein twins! :-laf Lloyd i thought third gens wont light twins! :-laf

I don't know, did it feel like it lit them the other night from a stop??? LOL :-laf

 

[lmills]

Is the HX40 the stock turbo that came on the truck? Who makes the HT3B and what is a comparable turbo size.



wayne

No, the HX 40 is not the stock charger. It is however available off the shelf as is the HT3B which is another old school design turbo that has been used for years in twin set ups.

 

[RVTRKN]

The Question was asked about stock and EGT, if you keep your RPM's up while pulling grades even if you have to down shift to maintain RPM(I like 2500 RPM) and slow to 40 MPH in forth gear (see sig) then you will never have to worry about EGT. Your acceleration in this configuration is a lot better as well to pass the DMAX's that are bogged down by Torque Management when they have to slow down for the same reason you did on the grade, you know, the semi's passing 2 MPH more than the one in the truck lane causing the jam. The danger is trying to maintain speed more than RPM. If you Bomb your CTD than its the first to get installed (pyro gauge)before any other upgrade no matter what RPM you run.

 

[DerekW]

How come you bend a rod when liquid enters the cylinder? I always thought that since liquids don't "compress" as much as gasses your compression goes through the roof. With that said, doesn't water spray do the same on a smaller scale?



Sorry I re-read your post. So it is vaporized and compressable.

Try to understand that the water injection systems spray water through a very fine precision sized orfices in a nozzle at a very high pump psi output. This creates a spray like a fuel injector does. A water injection kit is not like a garden hose hooked up to the air intake stream and flooding the engine. Try to imagine this: if a water injection system flooded the engine and bent or broke rods by flooding the engine, who would want to buy the kit if it took away all horsepower by breaking all the rods (you keep getting it once the engine started shaking) and you had to get towed. If a water injection kit made your truck have to ride on a roll back everytime you turned it on, do you really think it would be popular and even be talked about on any combustion engine.



I am just a guy trying to be your friend by passing on to you what one has taught me, Common Sense.

 

[DerekW]

First off, lookup Thermolysis and how it pertains to breaking water down to get the hygrogen (highly flammable) out. After you get done with that, research the temps and pressure in a diesel engine under load, the vapor curve of water, then get back to me.





Second, compression, or compression ratio as they are essentially the same thing, is the relationship of volume of a cylinder with piston at BDC to the same cylinder at TDC. It is a mechanical factor based on the construction of the engine. YOU CANNOT CHANGE COMPRESSION BY INJECTING WATER!!!



The ONLY thing injecting water does is change the density of the air charge. Change the density of the air charge changes combustion temps. IF your water injection is working correctly the combustion flame can actually burn hotter with less overall EGT's.



Water injected in a fine stream into a 300 degree plus air charge then compressed at 17 to 1 is NOT going to be liquid at at a pre-injection temp 700 C. It will be vapor which is compressible and once again all it is doing is changing the density of the air charge. The denser the charge the more heat that is needed to raise the temp.



From just the pretty pictures that were posted there is no way to know for sure what happened. The 1500 degree temp is not too much if it is for a short time in the combustion cycle, but, advance the timing too much and the 1500 is too much. The only thing that is a given is it was TOO HOT for TOO LONG and spraying water on it did not help.

I have always said to people we need to use our military to protect the bermuda triangle. Theres all sorts of methane gas down there (the cause of engines to stall-source mythbusters) all someone would need is a small charge on the ocean floor and it would release methane, burnit, then it could get hot enough to burn water, and overall you would have a huge disturbance under water which could cause a huge tidal wave and maybe even an earthquake. Maybe I ought to be writing to the president about that one instead of trying to use my bermuda triangle theory as a example off how neuclear water injection is inside of a diesel engina