Testing Water Injection in a Gasoline Engine.pdf

Testing Water Injection in a Gasoline EngineTesting done by Rudy Stefenel - 5/10/2009

PURPOSE:

To find out if water injection will actually increase the efficiency of a gasoline engine.

If it does work, find out what is the optimum rate is to add water to the carburetor air intake under the test conditions.

DISCUSSION:

There are three purposes for using water with a gasoline engine, other than radiator cooling, that I know about.

1) To improve the miles per gallon of gasoline automobiles.

2) To help cool gasoline engines when they are under heavy load. This was done with some war airplanes to help keep the engine cool during take off. The water was injected into the air fuel-air mixture somehow.

3) This third way is not water injection. Some of the electrical energy created by the alternator of the automobile is to used to convert water into hydrogen and oxygen gases. The hydrogen is fed into the carburetor to add as part of the fuel. I don't know if anyone feeds the oxygen into the engine too.

This test report only covers the first purpose: to improve the miles per gallon (efficiency) of a gasoline engine.

There are water interjection devices on the market for automobiles, but just because they are there for sale, it does not prove to me that they really help.

The testing documented here is a reasonably accurate method using a gasoline generator with a fixed load. The generator has a governor to keep the gasoline engine speed constant. A fixed load and a controlled speed are ingredients for a good repeatable test.

I used gravity feed, a needle valve, and a small orifice to inject water into the carburetor of the generator. The amount of water is controlled by the needle valve setting and the height of the water supply above the engine carburetor.

CONCLUSIONS:

My conclusion is that it is likely that there is no improvement, and if there is any improvement, it is not significant.

I found slightly over 1 percent improvement at one rate of adding water, but this is masked by the inaccuracy of the tests done. If I repeatedly test with just regular unleaded gasoline alone, I will find more than 1 percent difference between tests.

Based on this testing, I am not going to bother adding water injection to any gasoline automobiles that I own for the first purpose mentioned earlier.

It would be interesting if there is any improvement with water injection using a diesel engine. Maybe someday, I may dig into this.

TEST METHOD:

The gasoline generator's gas tank is disconnected and the carburetor is connected to a pipette, which serves as the gas tank for these tests. The engine efficiency is compared by timing the flow of 30 milliliters of gasoline through a pipette repeatedly.

The first test is with plain regular gasoline to get a reference.

The next test is done with a water injected into the carburetor.

Each test that follows is done with a different rate of water injection to hopefully find an optimum amount for best efficiency.

This is a great place to do this sort of testing. I am setup under a tree, and it is comfortable even on a hot day. I bring my lunch when I do this sort of testing. By the way, I keep a fire extinguisher handy just in case. Scientific testing, and outdoors too, what a life!

TEST SETUP 5/10/09:

Location: Stabilizer Solutions, in Milpitas, thanks to Peter Herrera!Regular Gasoline: Union 76 Regular.Gasoline Generator: Champion Power Equip. 1200 Watt Test Load: One 900 Watt waffle iron with its thermostat disabled.

Here is the test set up showing the electric generator, and the 900 waffle iron. Also a jar of water is shown on a ladder as part of the gravity feed for the water injection.

The water flows from the pipette through clear fuel line to a copper tube clued to a cement block. The cement block is there to keep the engine vibrations from reaching the pipette. It is much easier to see the fuel level when the fuel is not vibrating. The fuel line continues from the other end of the copper tube, through a fuel filter, and then to the carburetor of the engine. As you can see, it is easy to time the fuel flow between marks on the pipette. For the tests done in this report, I timed 30 milliliters of fuel flow each time. The fuel is always Union 76 Regular unleaded gas. Only the amount of water injected is changed during each test.

This photo shows the jar of water placed on a ladder step. The water pressure is adjusted by choosing which step the jar is placed on. This is gravity feed.

Bricks were used to get the jar at places in between steps.

This photo shows how I timed 5 milliliters of water flow using a stop watch. The narrow beaker is calibrated in milliliters.

ENGINE WARM UP using Regular gasoline:

Warmed up the engine for 15 minutes while adding regular gasoline to the pipette to keep it from emptying out.

All test times recorded are in minutes and seconds all through this report. As an example 2:11 is two minutes and eleven seconds.Another example is 2 minutes and 33 and a half seconds: 2:33.5

TEST DATA:

Here are the times logged for 30 milliliters of fuel flowing using straight regular unleaded gasoline:

The ambient: 68 degrees F. ( Union 76 Regular gasoline only ): 2:32, 2:37, 2:36, 2:40, 2:37, 2:31 Average: 2:35.5

Ambient: 68 F.( Union 76 Regular & 5 ml water in 2:00.5 minutes): 2:31, 2:30, 2:34, 2:31, 2:31, 2:33 Average: 2:31.7

Ambient: 68 degrees F. ( Union 76 Regular & 5 ml water in 1:37): 2:23, 2:24, 2:21, 2:23 Average: 2:22.75

Ambient: 71 degrees F. ( Union 76 Regular only, no water): This was doneto confirm that everything is working correctly.2:34, 2:37, 2:40 Average: 2:37

Ambient: 72 degrees F.( Union 76 Regular & 5 ml water in 2:36):2:27, 2:28, 2:26, 2:31 Average: 2:28

Ambient: 72 degrees F.( Union 76 Regular & 5 ml water in 3:46):2:31, 2:31, 2:33 Average: 2:31.67

Ambient: 78 degrees F.( Union 76 Regular & 5 ml water in 7:21):2:29, 2:27, 2:30 Average: 2:28.67

Ambient: 77 degrees F.( Union 76 Regular & 5 ml water in 13:28):2:31, 2:31, 2:43, 2:29, 2:32 Average: 2:33.2

Ambient: 77 degrees F.(Union 76 & 5 ml water in 29:0)2:32, 2:31, 2:33 Average: 2:32

Ambient: 77 degrees F.( Union 76 Regular only, no water): Another reference check.2:28, 2:31, 2:41, 2:37 Average: 2:34.25

Ambient: 77 degrees F.( Union 76 Regular & 5 ml water in 19:1): 2:36, 2:38, 2:40, 2:37, 2:37 Average: 2:37.6

Ambient: 77 degrees F.( Union 76 Regular & 5 ml water in 14:34): 2:36, 2:36, 2:37 Average: 2:36.3

Ambient: 77 degrees F.( Union 76 Regular & 5 ml water in 12:14): 2:31, 2:35, 2:34 Average: 2:33.3

Ambient: 77 degrees F.( Union 76 Regular & 5 ml water in 14:34): 2:36, 2:36, 2:37 Average: 2:36.33

Three separate tests were done using no water, and they are tabulated here and averaged. The first column is minutes and seconds for 30 milliliters of gasoline flow. The second column is the same data converted to seconds. The last row is the average of the top three and I will be using this average when I tabulate all the data and chart it below.

Here is all the data tabulated to create a XY Chart. To really make sense out of this, see this data charted on the next page.

Time forTest to see gasoline how much This engine

time Calculates to to useto fill a this rate 30 ml.

5 milliliter of water gasoline flask Converted injection Average Converted

to Time to Minutes Seconds Minutes Seconds

1:37 97 0.01031 2:22.75 142.752:00.5 120.5 0.00830 2:31.80 151.802:36 156 0.00641 2:28.00 148.003:46 226 0.00442 2:31.67 151.677:21 441 0.00227 2:28.67 148.6712:14 734 0.00136 2:33.30 153.3013.28 808 0.00124 2:33.20 123.2014:34 874 0.00114 2:36.30 156.3019.10 1150 0.00087 2:37.60 157.5029:10 1750 0.00057 2:32.00 152.00

no water no water 0.00000 2:35.60 155.60

milliliters/sec.

2:35.50 155.50 No water2:37.00 157.00 No water2:34.25 154.25 No water2:35.60 155.60 Average no water

The X-axis is time in seconds for 30 milliliters of gasoline flow through the pipette. The Y-axis is the rate of water injection in milliliters per second. The a red line is hand drawn line that averages through the data points.

As you can see, the engine efficiency drops in general as more water is added. Even if you were to take the highest point and compare that to the average of all the no-water tests, that would indicate only about a 1-percent improvement.

The testing is not accurate enough to call that a 1-percent improvement and even if it was accurate enough, just a 1-percent is not worth all the trouble of adding water injection for me to bother with it.

Rudy Stefenel 5/21/2009

0.0000 0.00057 0.00087 0.00114 0.00136 0.00227 0.00442 0.00641 0.0083 0.01031135

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