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How to measure meth/water mix?

18K views 24 replies 10 participants last post by  Chief 
#1 ·
I'm trying to figure out what the best way to get a 75/25 meth/water mix.

I have VP racing methanol, and i am trying to make a mix tonight,

any advice?
 
#2 ·
FSRbikr98 said:
I'm trying to figure out what the best way to get a 75/25 meth/water mix.

I have VP racing methanol, and i am trying to make a mix tonight,

any advice?
either a measuring cup or a weighing scale

cup is the easier method

http://www.ashland.com/pdfs/technical/AD Chemicals - Freeze-Flash Point.pdf

methanol has real low surface tension/viscosity, it will "pour and splash" everywhere except where you want to get it into :eveilgrin
 
#4 ·
yes the distilled water is a must, and i figured a measuring cup would do the trick but i just wanted to be accurate.

Thanks for the help
 
#5 ·
I'm trying to read the PDF you posted, and i do not quite understand the values. It says meth/water mixture, and % by either, can u explain how its calculated?
 
#6 ·
methyl alcohol = 0.791g/cc
water = 1.0g/cc

using measuring cup - 1000cc basis:

750ccMeOH + 250ccH2O = 1000cc
750/1000 = 75 v/v% methanol in the methanol/water mix

density = mass/volume

0.791 = mass/750
mass = 593.25gms methanol in the above 75 v/v% methanol/water mix

593.25gms methanol + 250gms water (water = 1.0gm/cc) = 843.25gms

593.25/843.25 = 70 w/w% methanol

therefore, 75 volume percent methanol in water = 70 weight percent methanol in water
 
#7 ·
ok so if i do 1 cup of water and 3 cups of meth what percent am i looking at

holy shit i wasnt that great in math, but damn dude i dunno wtf is that up there haha. I believe the lower portion of that equation is if i'm measuring the meth out using a scale correct?
 
#9 ·
ok thanks man, thats a good bit of info you posted there.
 
#10 ·
Ok but i heard you have to messure by WEIGHT, not volume? I use to mix one gallon water one gallon meth, 50/50 right??? WRONG, from what i was told water weighs more so that ='s one gallon water, one gallon meth, you have more water density than meth. So its not really a 50/50. This is sooo confusing, So now i do gallon water gallon meth and i have a line on the gallon jug i use. its about 1/4 of the gallon jug, Got no clue how close it is to 5050 but i belive im close may be more 40-60 but i mix it the same every time so my tune is good. Runs good whatever mix im mixing lol. But still dont understand the facts on the proper way to mix it.
 
#15 ·
Methanol weight 6.63 lbs/US gallon

Water weights 8.3436 lbs/US gallon

So its closest to a 3/4 ratio, For lack of making it easy to mix. Your more than welcome to break out the scale and do it that way.

Most in the fluid world will say it needs to be done by weight. When we recomend a 50/50 we mean volume just because of the ease of mixing. Its what most eveyone runs and it runs well.
 
#17 · (Edited)
honestly since water is heavyier than meth,ur best bet is to add 1 bottle of water for even 3 bottles of meth..so if u have a normal size water bootle(20oz or so) 3 bottles of meth is 60oz's and 1 bottle water is 20oz..so ur meth-water ration is 3-1..which is 60/20.if u want u can add more water but than it will be close to evening the mixture.ull never have close to 50/50,as water will always be heavier..so it will either be 51/49 or 49/51.i add 5 bottles of meth and 2 bottles of water,and that usually fills the whole 1.5 gallon tank
 
#22 ·
it works out to be a 1.3 : 1 (meth:water by volume) for a true 50/50 mix.

A 1:1 (again by volume) mix yields around a 56% water to 44% meth.

It all really depends on what you are injecting meth mainly for, latent heat removal or knock suppression.

Heres a link to a PDF worth reviewing

http://www.methanol.org/pdf/FuelProperties.pdf

10Kg of air, Gasoline's latent heat capacityof 350KJ/Kg
Water's latent heat capacity of 2256KJ/Kg
Methanol's latent heat capacity of 1109KJ/Kg



Each of the following chart show a 25% percent increase in Methanol concentration of the mix.



lastly, just methanol is added and no water. The chart on the right is 100% water



The two charts show (first and last) will require you to inject twice the amount of methanol to equal the latent heat of water alone

Below is quoted from Richard L at Aquamist
"Water and methanol injection does the same job in different ways, they both perform in-cylinder cooling and knock suppression well. Since water has a higher latent heat value than methanol, you need to inject twice the amount of methanol by mass to extract the same amount of heat during combustion. This is why all pure alcohol injection systems require a bigger jet, you need to inject 2.5 times by volume more than water. This makes little difference in practice except you need to find a bigger container.

Effect on knock suppression is totally different:
Water suppresses knock by quenching peak flame front temperatures hence regulating the frame propagation speed ? (too fast burn promotes knock). In-perfect charge distribution produces lean and rich pockets. Lean pockets burn at a higher temperature (oxygen-rich = faster) compared to fuel-rich pockets (excess CO slows down burn speed).

Alcohol suppresses detonation by increasing the knock threshold value of a given fuel grade. Since large amount of alcohol is required to control in-cylinder temperatures, air/fuel ratio will be affected significantly. Some fuel has to be removed to avoid over-rich mixture.

Power producing potentials:
In theory, more power will be produced if more charge is jammed into the combustion chamber, resulting in higher cylinder pressure and temperature. In practice, the associated components such as pistons, turbo turbine, etc has a finite operating temperature constraint. This is normally reflected by the EGT. The general accepted EGT figure is about 900C.

Power is basically a force exerted onto the piston per unit of time. Force (pressure) is generated with heated air in a confined space. If cylinder pressure can continue to increase without temperature rise, we have the ultimate power plant. Water injection and alcohol injection will be a good tool to perform this work, lets examine this in more details how each concept can help achieving this.

POWER TUNING:
(Assuming we have a powerful ignition system, a strong engine and unlimited supply of air and fuel).

For water: the task is relatively simple. First generate as much heat as possible by adding more boost and fuel. Water is then injected to absorb the excess heat until EGT is within a permitted safe level. Overall BMEP (Brake Mean Effective Pressure) is now increased due to the vaporized water. The amount of BMEP increase will depend on the mechanical strength of the engine structure. Water?s ability to push the power capability is almost unlimited.

For methanol: First consider using methanol as a fuel instead of Gasoline. Methanol?s ability to increase power is confined to the knock threshold, and available heat to increase the BMEP of an engine. Methanol has only about half of the energy content of gasoline, so twice as much methanol has to be injected to produce the same power. As twice the amount of liquid has to be injected, the cooling effect is huge, resulting in over-cooled combustion chamber, limiting the BMEP. A 100% methanol engine has to use multi-spark ignition system to ensure the mixture is constantly being re-ignited due to the cold combustion chamber. Within those constraints, there is still huge potential of power increase.

A good compromise to inject a percentage of injected into a gasoline engine. This will ensure good inlet and in-cylinder cooling effect, but how much? From reading many results form various forums, it appeared to be between 10-30% to fuel. Unfortunately, the results were not consistent, some got excellent power increase, some experienced engine knock, some misfires and some with very low EGT. Why?

4-5 years ago, AI system was very basic, at a certain manifold pressure, the pump starts and deliver a fixed amount of alcohol into the engine. In those days, results have always been very consistent and yield excellent power increase. But for the past few years, the results have been a mix bag. I could only put this down on the availability of the 2-dimensional AI controller. They are termed as an electronic progressive AI controller. Method of delivery is very similar to the mechanical rising-rate fuel pressure regulator. The flow is governed by the pump speed, the controller reads the manifold pressure via a MAP sensor, translates to a PWM drive signal to the delivery pump.

Lucky for some, the availability of stand-alone, piggyback type of engine controllers give user a high degree of control, changing fuel and ignition timing is a merely rapping a few keys on the laptop. In my view, I think this is the reason for the inconsistent result ? user?s interpretation of quite a complex ratio of methanol and fuel. Taking fuel out of the factory ECU to accommodate a methanol delivery system that has no reference to RPM, is a tall order. There are a few guys on this forum have managed it, I take my hat off to them.

My personal view on this relatively new concept requires a great deal of patience, dyno result means very little compared to logged data. Dyno-graphs always cause argument. I would really hope to see more logged graphs with AFR, Methanol flow rate, and EGT. If possibly the log should include a second to fourth gear run-up so we can spot the afr change due to Methanol. For those who has just embarked on the WAI, tune with 100% water - W50:M50 - 100% methanol and lastly 100% for ultimate power.

Need to clarify, get to experiment with water first and then add alcohol to until you are running 100% methanol. Lastly, you need to go a bit mad with crazy power, 100% water will be best."

"Just to follow up on this... this is a very commonly confused issue. I just wanted to confirm that as stated above a wideband reads lambda which it then scales to an AFR based on the type of fuel you are using. This is why the AEM UEGO for example has you specify the fuel type. If you are running gas it will take the lamba and multiply it by 14.7, if you are running methanol it will multiply it by 6.48, if you are running propane it uses 15.73, ethanol = 9.02, and compressed natural gas = 14.53.

This helps with the issue of dealing with reading the A/F when methanol is being injected

Australian DIY Wide Band Information
 
#23 ·
maybe one of the vendors can clear this up but i have read (old WW2 testing) that anything over 50% meth increases your risk of pre-ignition (instant death) is this true or just BS ?? (not sure if they were using weight or volume mix)
 
#25 ·
cooling mist varicool trunk kit. And mix your self. You can do water and heet. or get real meth and mix that. Its alot cheaper than paying for premixes and shipping costs.
 
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