Thought experiment

[Begle1]

If I'm running a standard water injection system and I'm injecting water in the normal location.

Lets say I have a magical gadget that takes out all the water I inject right as the intake air goes through the intake valve.


What difference will I notice when I turn on my magical gadget and take the injected water back out before it enters the engine?

[full pull]

I dont follow?

Are you saying the water would only be used to cool the intake air, and possably add more oxygen, but the water would never enter the cylinder?


As to what would difference you would notice... im sure once the magic thing is turned on, you would notice rainbows and unicorns coming from the exhaust.

[zstroken]

Are you suggesting that your injection of the water will cool the intake charge, and pulling the "warmer" water back out will help to drop the intake charge?

[Drasko]

Youd have cooler charge air but i dont know by how much. As for your magical gadget, what is it? Im thinking of how you could do this but havent come up with any results. Only thing i can think of is separating the hydrogen molecules from the oxygen but the youd most likely have a big BANG inside the cylinders when the hydrogen lights off. Care to explain?

Or are you thinking of having extremely long charge air piping and trying to get the water molecules to condense out of the air and collect in a pan or something?

[Begle1]

I don't know what difference it'd make. Water does several different things, I have yet to differentiate what things it does in the cylinder and what things it does in the manifold.


The thought experiment asks what would happen different if the water was injected and then removed right before entering the cylinder. Would EGT's drop without as much a boost rise? Would there be much less or no EGT drop? Would it make the water totally ineffective or would you not notice a change in efficiency?



There is no magical gadget, think of it as a small demon that can just grab out all the water molecules with his little claws as they fly past.

[Drasko]

hmmm so kind of like a cat nabbing at some flies by the window hmmmmmmmm

lmfao

I think you see a minor drop by the cylinder pressure should rise due to the water molecules inside so id have to charge air temp drop, minor egt drop, and the same cylinder pressure if it not just a c()nt hair lower?

[zstroken]

Alot depends on the differential between the water and the charge air.

[Cummin_un_glued]

wouldnt that be basicly the same as an air to water ic....in theory i mean

[SHughes]

Originally Posted by Begle1

There is no magical gadget, think of it as a small demon that can just grab out all the water molecules with his little claws as they fly past.

The little demon would expel so much energy it would impart more heat back into the air than the water had previous removed.

[Begle1]

Originally Posted by Cummin_un_glued

wouldnt that be basicly the same as an air to water ic....in theory i mean

So what does water injection ever do more than a good air to water IC in the first place?

[DEZLFREK]

from my thinking is the water puts the flame out= less heat and the increase in hp is from increasing the compression because the water doesnt compress..

[Begle1]

Water compresses just fine, once it's steam.

[DEZLFREK]

but its orginal liquid displacement stays the same= raises the compression.. every point of compression is worth about 40hp in our 12v's.. it puts flame out thats why the temps go down..

[Drasko]

I agree with Dezl. The compression does go up along with keeping the flame down a bit. Water is harder to compress than air. Once it heats and creates steam, it helps the expansion of the gasses.

[roachie]

Has anyone ever determined if it actually becomes steam or if it is broken down into its component elements?

[Begle1]

It definitely doesn't break down into hydrogen and oxygen; that is called thermal decomposition and for water occurs over 3000 degrees F.


My ultimate question here is what effects of water injection occur through the water cooling the air down in the manifold, and what different effects of water injection occur once the water is in the cylinder and starts to encounter compression and fire.

[roachie]

I would argue with it increasing compression very much. However I would agree with it becoming steam during the power stroke. Steam is very very powerful.

[Drasko]

in cylinder pressures would increase. my bad for using compression as it is actually the wrong word to use. The water would increase the in cylinder comperssion as it creates steam but now that i think of it, it might actually increase the compression slightly before combustion but im not certain. Im thinking it still would although the water does displace air in the cylinder but air is still easier to compress than water so i feel the pressures would be up on both the front and back side of the power stroke with water injection in the system.

[DEZLFREK]

Wrong on both counts.
Static compression is what raises power. That is the expansion ratio between chamber volume at TDC and BDC. Dynamic compression, such as boost and WI, has no effect on power or efficiency. Its the extra oxygen that does that.
WI doesn't put the flame out, it lowers the combustion temperature. If it puts the flame out you get a severe reduction in power and high exhaust smoke from the leftover unburned fuel.[/QUOTE]

ok so most everyone knows that water compresses 0(zero).. so if wi doesnt increase power from raising compression or cylinder pressure how come almost everyone that used it as a "power adder" blew head gaskets? and if it does just add power then why not just dump a couple gallons in every second? imo there is a max and a balancing act that goes on..
in any rate explain how it lowers egts and raises hp.. im baffled and curious how it does in your opinion..

[GOT-Torque]

Originally Posted by Begle1

What difference will I notice when I turn on my magical gadget and take the injected water back out before it enters the engine?

Depends... Is it holy water?