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Old 10-13-2008, 03:44 PM   #1 (permalink)
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Question --- Water injection VS Steam Injection ---

I know that water injection supresses detonation, and you can increase timing on the engine (all because the water vaporizes in the combusion chamber and cools etc etc).

But what if you injected the water as a vapor already? Heat the water to around 300 degrees and inject it... what would happen? Would it heat the engine up to much? Could you still advance timing?


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Old 10-13-2008, 08:58 PM   #2 (permalink)
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Wouldn't have the same cooling effect. Remember heat of vaporization: it takes a whole bunch of energy to turn water at 212 F to steam at the same temperature.
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Old 10-13-2008, 09:32 PM   #3 (permalink)
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The benefit of water injection is that you can get cheap fuel(meth) in the form of winter windshield wiper fluid, and lean out your top end, or any end that the WMI is spraying at. Water as a vapor may help, but it's the phase change that sucks out the heat, and allows more timing/boost/whatever. I don't know if the steam would do much as far as absorbing heat, but I know it would absorb space.
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Old 10-13-2008, 09:36 PM   #4 (permalink)
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It'd probably make the innards nice n clean.
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Old 10-14-2008, 01:01 AM   #5 (permalink)
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Well if it "absorbs" space then that is good when cruising because it means less fuel and more throttle (opening more, reduce pumping losses).

I dont know if I am right, but doesn't steam have more surface area than drops of water? What i am trying to get to is if this would make up for the hotter temp of steam vs water and have the same cooling effect...
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Old 10-14-2008, 02:16 AM   #6 (permalink)
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Surface area is a meaningless concept for steam: it's a gas, which by definition doesn't have a surface.
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Old 01-24-2009, 10:45 AM   #7 (permalink)
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Quote:
Originally Posted by basslover911 View Post
But what if you injected the water as a vapor already? Heat the water to around 300 degrees and inject it... what would happen? Would it heat the engine up to much? Could you still advance timing?
What would happen is you would just pump the crankcase full of water.
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Old 01-27-2009, 04:50 PM   #8 (permalink)
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Quote:
Originally Posted by Frank Lee View Post
It'd probably make the innards nice n clean.
That would be a BAD thing, because the cylinder walls need to be oily.

Not only does water injection absorb heat and cool the engine, but while it is absorbing the heat, it converts to steam and expands, assisting the other combustion gasses in pushing the piston downward. This effect would be completely lost if it was steam already.
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Old 01-27-2009, 08:26 PM   #9 (permalink)
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As far as taking up space in the combustion chamber, this was discussed in another thread using gaseous CO2... the end effect could cause a problem, unless the influx of steam/water/whatever was specifically controlled to allow the air/fuel mixture to remain as close to the spark plug as possible. What you wouldn't want is a cloud of steam shrouding the spark plug, because you would then have a net loss of power, a bunch of wasted fuel for each spark event, and a net loss of MPG.

Oh, and non-oiled cylinder walls as well.

You can add propane to your gas engine relatively easily if you want to use less gasoline per combustion cycle, but in order to lower the actual size of your engine, you should just REALLY lower the size of the engine, instead of trying to add stuff to your mixture.
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Old 01-27-2009, 08:52 PM   #10 (permalink)
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^ Thing is, turbine engines actually use steam (from water being burnt into steam in the exhaust area, just like what I wanted to do), and it works perfectly fine. Its actually called "energy recovery".

As far as being mixed in with the fuel, it will be a homogenious charge since it will be injected FAR behind the throttle plate and it will thoroughly mix with the air....

Who knows, I am just theorizing here


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