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  #11  
Old 11-04-2012, 04:51 PM
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Russ McCutcheon Russ McCutcheon is offline
 
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Quote:
Originally Posted by rocketbob View Post
Camguard works by enhancing the film qualities of the oil which prevents components of blowby from causing varnish and rust. The gentleman who formulated Camguard originally used the same formulation for Exxon Elite since he formulated that oil as well. So basically it is an supplemental version of Exxon Elite.
I'm using Exxon Elite there for I am using Camguard already,,, good to know.
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  #12  
Old 11-04-2012, 06:45 PM
Ted Johns Ted Johns is offline
 
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Quote:
Originally Posted by Mike S View Post
Ernst, I have heard that before, but the thing that is not usually made clear is that it is water vapor, not liquid water. And, is it refering to a gallon of vapor, or how much vapor would be generated if a gallon of water totally evaporated.

Still, I do not know if the statement is correct or not.

What part of: 2C8H18 + 25O2 --> 16CO2 + 18H2O don't you understand?

Yes, the main byproduct of gasoline combustion is carbon dioxide and water. And yes, the water is in vapor (i.e. gaseous) form, considering the significant heat of combustion of gasoline.

I could show the work need to convert the above idealized balanced equation into gram molecular weight equivalents, but it's easily googled, and I think you get the idea.
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  #13  
Old 11-04-2012, 08:07 PM
SHIPCHIEF SHIPCHIEF is offline
 
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The water vapor produced by combustion is mostly expelled out the exhaust at a very non-condensible 1200+ degree F.
Some small amount of water vapor, combined with other exhaust products seep past the rings and exhaust valve guides, where they come in contact with the inside of the engine, and the oil.
If the oil is a nice 185 F or higher, most of these gasses should pass right out the crankcase vent as a vapor.
You get worrysome corrosion when the remaining vapor (ladened with lead salts and acids) has a chance to condense in the engine and remain there for some time. Presumably, your engine is still fairly hot when you shut it down, so most of the last bit of water vapor could still be expelled by it's vapor pressure.
The additives in your oil neutralize these acids, if you have been changing that oil when you are supposed to. I suppose you could dip a PH test strip in your oil to make sure it hasn't gone acidic.
Given enough time, good oil fails in tight places like bearing journals, also the steel cylinder and iron cam near the crankcase vent, where moist air can enter when the atmospheric pressure fluctuates.
Bummer. Why don't you save yourself some money and go fly? Follow the engine manufacturer's reccomendation and fly long enough to dry out the inside of your engine.
I like the idea of Camguard or other additives when they could reasonably benefit.
The presentation had good pictures, thanks for posting it.
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Last edited by SHIPCHIEF : 11-04-2012 at 08:22 PM.
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  #14  
Old 11-04-2012, 08:23 PM
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Forgetting the combustion process for a minute, if you did some rough numbers on 1 gallon of fuel at peak or LOP rates, thats 2.68kg of fuel and 40kg of air.

Air is roughly 1.25kg/m3 and a m3 holds about 6-10 grams of water per cubic metre.

That means on average something like 330ml of water injested from the air for every gallon of fuel burned. Or 1 gallon of water for 11-12 gallons of fuel.

Unless I got my units of measure wrong
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  #15  
Old 11-04-2012, 09:01 PM
N427EF N427EF is offline
 
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RV10inOz,
Now that sounds more like it, 330mml per 1 Gallon,
or somewhat more than a 1/4 pint per gallon of fuel burned.

According to their sales literature:
Making people believe that you pump a gallon of water through your combustion chamber for every gallon of fuel burned is what ruins their credibility and is the reason I call it Snakeoil.

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  #16  
Old 11-04-2012, 09:06 PM
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Quote:
Originally Posted by Ted Johns View Post
What part of: 2C8H18 + 25O2 --> 16CO2 + 18H2O don't you understand?
Any..........
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  #17  
Old 11-04-2012, 11:09 PM
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Quote:
Originally Posted by N427EF View Post
RV10inOz,
Now that sounds more like it, 330mml per 1 Gallon,
or somewhat more than a 1/4 pint per gallon of fuel burned.

According to their sales literature:
Making people believe that you pump a gallon of water through your combustion chamber for every gallon of fuel burned is what ruins their credibility and is the reason I call it Snakeoil.

No, I believe you are missing the point. RV10inOZ said "forgetting the combustion process for a minute..." and was just talking about the ADDITIONAL water brought into the cylinders from the intake air. He was not discounting the original premise of the combustion process generating water vapor that was also layed out in the chemical equation earlier. Embrace the snake oil!
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  #18  
Old 11-05-2012, 07:04 AM
N427EF N427EF is offline
 
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Default Stay with me

Stay with me for one more round please.
After I put my ignorance on display I am still confused as to what exactly we are talking about.
When someone says generating 1Gallon of water I assume that to be liquid.
(sales literature)
Is someone talking about water vapor, in gallons? Could someone just exactly tell me how much liquid water is generated by burning 1 gallon of gas.
No formulas please, gallons or liter.
And BTW I am a sucker for snakeoil, I use Lenkite (avblend) and MMO.
thanks.
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  #19  
Old 11-05-2012, 08:24 AM
zav6a zav6a is offline
 
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Default Liquid water

Exactly 0 gallons liquid water generated by the combustion process. Too hot in the combustion chamber.

In the crankcase though, it is another story. What ever blows by the rings has the potential of condensing to the liquid form there. Especially when you first start the engine and all of the internal surfaces are relatively cold.

Water is also slightly soluable in oil, so it is not so simple as simply keeping the crankcase temp above the dewpoint and venting it overboard. Some of the water vapor will be dissolved in the oil, even at 180F.
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  #20  
Old 11-05-2012, 08:26 AM
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Ernst, There is no single quantitative answer to your question. All the water produced by combustion will be in the vapor phase initially due to the high temperatures. A small portion of that vapor will mix with your oil, and if your oil is below the boiling temp of water, it can condense and exist as liquid water.

I think we may be getting hung up on the volume issue here when the point is that there is a pathway for water to enter your oil and that can lead to rust. There are ways to minimize it, but it's likely always there in small amounts. Also, keep in mind the power point presentation is likely a set of notes for a talking presentation, so we are not viewing the full presentation. I doubt the presenter ever intended to suggest that there is a gallon or more of liquid water in your oil sump at any time.

Regards
Erich

Last edited by erich weaver : 11-05-2012 at 08:29 AM.
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