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Water Injection?

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Old 10-21-2002, 12:05 PM
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Water Injection?

forgive my ignorance, but i'm just wondering what it is? i know some of the pullers use it--enterprise engine has it on their site. <br><br>what is it?
Old 10-21-2002, 02:36 PM
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Re:Water Injection?

It's a system like so:<br><br>Water is injected into the air stream after the turbo (sometimes before), using a high atomizing nozzle; The water cools the intake air before going into the engine. It's also said, but I don't know if it's proven that there's a couple explosive goodies in H20 if you know what I mean that in small could help the engine make power... but that's not any reason why it's done, Water injection is for EGTs. Anyhow. Typically a system consists of a water tank, a copper line from the bottom of the tank, the copper line wrapped around the exhaust to heat the water and turn it into steam where the steam raises up the line into the intake out of the line from the air being sucked in by the turbo.... or people use a high pressure pump and simply suck the water from the tank and inject it after the turbo in mist form. Only problem is making sure you watch the water level. Water injection typically injects a fair amount of water so it goes pretty fast. If you run out when you're relying on it with EGTs getting near the danger zone... that could be a bad day for you.
Old 10-21-2002, 03:07 PM
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Re:Water Injection?

hmm. i've always thought that water+combustion chamber=BAD. wouldn't there be some negative effects to adding water in the inlet?
Old 10-21-2002, 04:17 PM
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Re:Water Injection?

I think it gets so hot, that it instantly evaporates so it isn't that big of a deal. Could be wrong though.
Old 10-21-2002, 05:02 PM
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Re:Water Injection?

Ya, I though water+Diesel was bad.<br><br>Hence the &quot;water in fuel&quot; seperator and warning light.<br><br><br>phox
Old 10-21-2002, 05:49 PM
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Re:Water Injection?

I remember (in the old days) some of the piston driven airplanes I used to be crew chief on used water on takeoffs sometimes. P&amp;W 4360's, 28 cycls of pure power, 3500 hp each.
Old 10-21-2002, 07:44 PM
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Re:Water Injection?

Water + Diesel is VERY bad, but in a water injection system the water enters the combustion chamber with the AIR not the DIESEL. Hence, no problem.
Old 10-21-2002, 08:19 PM
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Re:Water Injection?

[quote author=chuck3 link=board=8;threadid=6114;start=0#55721 date=1035240593]<br> I remember (in the old days) some of the piston driven airplanes I used to be crew chief on used water on takeoffs sometimes. P&amp;W 4360's, 28 cycls of pure power, 3500 hp each. <br>[/quote]<br><br>I remember that as well.<br>Not first person, but Combat Flight Simulator.<br>Some of the planes have &quot;water injection system&quot; kinda acts like a shot of NOS.<br><br>phox
Old 10-21-2002, 09:29 PM
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Re:Water Injection?

I always thought water injection not only lowered EGTs but also increased the compression ratio. Am I on the right track?<br><br>Gene
Old 10-22-2002, 12:24 AM
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Re:Water Injection?

Water injection on the diesel usually injects a spray or mist of small water droplets. During combustion they evaporate, thus converting heat into pressure. So you get lower EGTs and higher torque. Had it for some of my diesels. Used a fuel injection system from a gasser. Very easy to do. Best results were to inject a mixture of 30%methanol, 5%nitromethanol and 65% distilled water. Don't do it on non wastegated turbos- also let engine run dry at least 10mins before stopping. <br>AlpineRAM
Old 10-22-2002, 12:43 AM
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Re:Water Injection?

Water injection is used quite a bit on diesels over in Europe. It is used mainly to reduce EGTs, but also helps on power output, and comes standard equipment on many diesel powered vehicles. <br><br>I think the very best system out there is the Aquamist. It is computer controlled, has a mapable output depending on boost and rpms, and has to be slightly modified for use on a CTD.
Old 10-22-2002, 01:34 AM
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Re:Water Injection?

The Aquamist system is quite nice, but promises more than it can keep. You can't make these systems foolproof. <br>I am currently working on the simulation of the CTD for my water injection system (in my spare time) Will post results when available.<br><br>AlpineRAM
Old 10-24-2002, 09:11 PM
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Re:Water Injection?

Water and alcohol injection is very popular with tractor/sled pullers. The engines with compound turbos have to run it between stages in most cases because they dont have the room for all the mazes of piping under the cowl to run intercooler and aftercoolers. Triple and quad turbo set-up are pusing manifold pressures over 250PSI. Not many intercoolers that are strong enough or even large enough for that kind of pressure and CFM. Aquahol is a slange for the homogenous water/alcohol combos.<br><br>Many pullers just blast the water directly into the face of the compressor wheel. The compressed air is generally hot enough to vaporize the water and help remove some heat of the compressed charge. Many systems on pullers and diesel powered race boats use the boost pressure being made to pressurize a vessel of the water or water/alky mix. It could be made adjustable to come on and turn off at certain boost levls.<br><br>Alpine, what are you doing your simulation in? <br><br>Don~
Old 10-25-2002, 12:12 AM
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Re:Water Injection?

Some where I read that the tractor guys were only running 950* egts using water injection. Some of them were running triple compound turbos and injecting the water between each one.<br><br>What has to be done on the Aquamist system to work with a CTD is to use their soloniod valve with another &gt;100psi pump. The system regulates the amount of water injected by pulsating the solonoid at different frequencies. The special solonoid valves and computer are the secrets to their system.<br><br>Spearco has a system with the tank being pressureized by boost pressure, which requires a much less powerful pump, if injecting post-turbo, and regulates water volume by boost pressure.<br><br>Injecting the water pre-turbo is certainly the easiest way of doing things.<br><br>Edge experimented with a truck/tractor puller system made in the midwest somewhere (Mitchell's I believe). This was a couple of years ago. It was very large and drew an incredable amount of juice because it used a starter motor to run the pump.<br><br>Alpine, lets hear more about your system.


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