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View Full Version : Anyone know the science behind water meth?


rage_blue
11-21-2010, 12:04 AM
I'm wonder if anyone knows whats happening inside the cylander when you start adding water meth to the mix. I've played with water meth befor, but I can't find any info on what its doing to the flame front and how does it get more oxygen to help complete the burn.

blkram
11-21-2010, 12:28 AM
A lil info.
http://www.labontemotorsports.com/ontrack/DIS_WP.pdf

rage_blue
11-24-2010, 12:01 AM
Thanks theres some good info there.

gdh11
12-10-2010, 08:30 PM
My biggest question with water/meth is the results in cylinder pressures and drive pressures? Does anyone know if the lits out there now create too much or is the increase in drive pressure ofset by the reduction in cylinder temps?

C111
02-16-2011, 01:41 PM
but I can't find any info on what its doing to the flame front and how does it get more oxygen to help complete the burn.

It doesn't do anything to the flame front. Evaporation of the water cools the air, increasing density, and the methanol is additional fuel, increasing power.

Does anyone know if the lits out there now create too much or is the increase in drive pressure ofset by the reduction in cylinder temps?
The increase in drive pressure is caused by the combustion of the methanol, which increases the volume and heat of exhaust gases.

C111
02-16-2011, 02:02 PM
A lil info.
There is a LOT of misinformation in that article.
"15-30% of the fuel not being burned during combustion" is false. The "15-30%" they quote is actually waste heat absorbed by the cooling system. This is common with EVERY engine, even today's modern engines.

"When the water particles enter the hot cylinder during intake, they absorb heat and convert to stream. The added mass to the combustion process helps to extend the downward force on the piston during the power stroke of the motor." Is also false. The volume of water taken in per intake stroke is too small to provide a measurable increase in combustion pressure. The increase in pressure comes from the combustion of the methanol.

"Methanol acts like a catalyst to help initiate diesel fuel burn in a cylinder cooled by water injection." Thats outright false.

"As the engines piston is forced down from combustion, the volume of the cylinder increases and at some point combustion of the injected diesel fuel will stop." Thats also incorrect. Autoignition temperature of #2 is 545*f, any engine load above idle quantity will have sufficient temperature to ignite diesel throughout the power and exhaust strokes."Fuel economy can be realized from complete combustion through increased horse power and torque generated from the same volume of diesel fuel." Also false. The MPG increase is an illusion, the need for diesel is displaced by combustion of the methanol. Power output of the engine needed to propel the vehicle doesn't change.

That article was created by a company selling water injection systems. If you want accurate information you should read a scientific study written by somebody that performed actual controlled testing.

rage_blue
03-04-2011, 08:08 PM
any idea where to read a study like this?

jellydonut
03-05-2011, 04:50 AM
any idea where to read a study like this?

Not2Fast: Water Injection (http://www.not2fast.com/thermo/water_injection/)
http://www.not2fast.com/thermo/water_injection/1999-01-0568.pdf

tornado112
05-04-2011, 08:18 PM
Water meth cools the charge air. Making it denser increasing power the meth acts as a cetane booster. much like 87 93 or 110.

ENafziger
05-05-2011, 04:09 PM
Not2Fast: Water Injection
http://www.not2fast.com/thermo/water...99-01-0568.pdf

Great links! Thanks!

--Eric

awenthol
07-14-2011, 01:15 PM
There is a LOT of misinformation in that article.
"15-30% of the fuel not being burned during combustion" is false. The "15-30%" they quote is actually waste heat absorbed by the cooling system. This is common with EVERY engine, even today's modern engines.

Most diesels are now closer to 30-40% BTE (depending on emissions sysem). So, roughly 60-70% waste energy through coolant, oil, exhaust, radiation, convection, etc...

"When the water particles enter the hot cylinder during intake, they absorb heat and convert to stream. The added mass to the combustion process helps to extend the downward force on the piston during the power stroke of the motor." Is also false. The volume of water taken in per intake stroke is too small to provide a measurable increase in combustion pressure. The increase in pressure comes from the combustion of the methanol.

Yep...last I checked it was pressure, not weight downforce on the piston that causes motion. However, I must disagree in that the water actually reduce cylinder pressure for a give amount of fuel in.


The MPG increase is an illusion, the need for diesel is displaced by combustion of the methanol. Power output of the engine needed to propel the vehicle doesn't change.

Exactly :Cheer:

Stark
07-14-2011, 08:57 PM
water when injected in to the air intake will do two things
1: it will take some of the heat out of the combustion chamber
2: it will increase the pressure in side the combustion chamber

how does it do this
1: it will take heat engery to convert the water in to steam (970 BTU to turn one pound of water into steam at the boiling temperature) right there is how water cools the combustion chamber
2: water has a converson rate of 1700 to 1 when it changes states ( water to steam) exmp. ( one cubic inch of water when changed to steam = 1700 cubic inchs of steam) thats how water increases the pressure in the combustion chamber

the methanol is an easy one its fuel add more fuel in to the combustion chamber and you get more power

awenthol
07-21-2011, 03:02 PM
Lowers cylinder pressure when all else constant. Also, you're looking at it wrong....you have to treat the system as saturated air, not water being vaporized.

eastern
07-29-2011, 07:48 AM
So is water meth a good or bad. I have it on my 08 for and set to work with my EGT had to remove to do work on truck, wondering if I should reinstall or ditch it. I used it mainly for towing. I am not a guru on this stuff but try to read as much as possible to edumacate (LOL) myself. Just read alot on other forums saying it is not good to use.

Stark
07-29-2011, 08:48 AM
It's good it will help keep temps down when towing and add a little power atthe sane time I would put it back on if it was my truck