My new water injection plans
 

I have ran water injection on previous cars and the big issue was always keeping the water flow metered correctly. I was browsing around looking at unrelated stuff and came across this pump. It should be here today so I will try hooking something up this weekend.

Peristaltic Liquid Pump

It is 12V and 300mA max current. Flow rate: up to 100 mL/min.

It has a low enough flow rate that I am hoping I can just run it in parallel with the tbi injector in the car and have it pretty close to the right gas/water ratio. My plans are to hook this pump up and plumb it into the throttle body in an unused vacuum port. I will put a gallon of water in the car with 1/10 gallon divisions so I can adjust it by putting a resistor in series with the motor until I get the ratio of 10 gallons of gas to 1 gallon of water.

If it works out the injector PWM signal should give me proportional water flow and after getting the speed right I can just change over to a larger water tank and have a pretty reliable system that will finally meter the water properly. It would be a pretty easy system to duplicate and get working on just about any car.

Just curious, are you attempting to introduce a second fuel to your engine similar the how propane is used in diesel engines?

It is an old idea that is used sometimes on engines to suppress knock. It has been generally shown to improve mileage a small amount. With water injection you can increase the compression ratio without knocking and advance the timing a little bit. I am of opinion that using excess heat to turn the water into steam thereby increasing the cylinder pressure is where the gain in mileage comes from.

I ran it before on my first Metro and I gained like 3-4mpg when it was working properly. The problem with the setups I tried and the commonly used fish tank gang valve setup is that it never stays at the proper ratio unless you fiddle with it before every drive. That is a huge hassle and not worth it. I always wanted to use a fuel injector setup sized at 10% the flow of the stock injector and just let the computer manage it. But I don't think a fuel injector would live long running straight tap water.

The nice thing about that pump listed in the first post is it can pump any fluid without having to interact with the fluid so it won't care about pumping water for a long time. I just have to get the speed of it right and I should have a more or less exact ratio all the time. The pump came in today but my variable power resistor didn't show up so I won't get to hook it up and test it till Monday most likely.

Verry intersting. I will follow this thread :)

I have a test setup in the car. I used some clear hose going from a water bottle in the cup holder to the pump then to a vacuum port on the engine. I wired it to the injector with no resistor on the wire just to get a feel for the max flow of the pump.

I started the car and the motor just jumped back and forth. The inductive kick from the injector was high enough to keep it from doing anything. I found a random diode I had laying around and put it inline with the motor to get rid of the reverse current. I didn't have a meter or a wiring diagram with me so I have no idea yet if I have it wired in the right direction but at idle it was pumping a very tiny amount of water so it was good enough for a quick test.

I will get a meter and make sure the power is going the right way to the motor and the diode is facing the right way. Then I can dial in the system but it looks like it should be no problem to get it working very well.

So far the total parts list is that pump listed on the first post and a 25W 200 Ohm Round Ceramic Wirewound Potentiometer and a diode. The diode needs at least a half amp current capacity or so. I will leave it hooked up and drive to work tomorrow and see how much water it uses. Then I will put the variable resistor in and try and dial it in.

I would take a picture but right now it is just a ball of duct tape on my battery handle and a bit of hose so it doesn't look like much.

Interesting... have not heard of it improving economy for gasoline engines (diesel engines, however, there's lots of testing supporting it)... I suppose the gains came after you advanced the timing?

That kit is made for turbo setups that are trying to get more power. That isn't really applicable to the setup I want to try. I want to meter tap water, not washer fluid with Methanol in it. Plain tap water will plug up a lot of pumps and injector setups over time. I won't advance the timing or do anything to the motor once I get this setup dialed in and just do a flat comparison of water vs no water before trying to tune anything. I still think the primary reason for the gain in mileage is the increased cylinder pressure so not changing anything else will be the easiest way to test that theory out.

With my test setup the motor does not turn on the pump when driven directly from the injector signal. The pulse just isn't wide enough to get it spinning with the pump on the end of it. I will experiment with a few things I can do to get it working a bit better before I resort to using a microcontroller to regulate the flow of water. I might have to find a smaller pump anyway. If I wire this pump to power and run it as slow as possible with the variable resistor it can empty a 16oz bottle in probably 10 min. That is going to be way faster than I can deal with.

I will have some time to experiment with it this weekend, I will hook it to a pwm controller and see how slow it actually can run. If it won't go slow enough I will get a much smaller pump and try again. The good thing about these pumps is they are pretty cheap so experimenting won't cost much.

what is the nozzle look like? wonder how much pressure it can pump.
i tried water injection on my 81 VW 1.6 diesel. it was crude. the engine kept running, no matter how much water i pumped in it. i got scared i would destroy it so i took it off when water came out the tailpipe.

The owner has come over here a couple of times. A friend tried it out on his (non-turbo) car... good for a small hp bump without a turbo, but not dramatic enough a gain to justify the price of the kits. Great on turbos, however... especially given the tropical weather.

I decided to register just because of this topic and the fact you own a DR650 :D I took a DR650 to Alaska from Pensacola, FL in 2013 and that was a blast. Ive also got a 4 banger duratec 5speed ranger, and have been reading up on how to improve my mileage.

Anyways, I thought Id put out another idea. The injector seems like it could be very cool, but as you mentioned its a pain to prevent it from clogging up. Perhaps you could filter the water with a reverse osmosis setup first? Or maybe run the water through a fuel filter? This may be a really dumb idea- not sure.

Back when I was a kid (late 90s), my dad and I worked alot on an 85 Chevy El Camino. One of the things we did was install what he liked to call "water induction". We took an old antifreeze bottle, a piece of garden hose, a wick meant for an oil lamp, a needle valve (can get them at home depot), and some vacuum line.

1) Put a vent in the antifreeze bottle where the handle was.
2) Cut a hole in the cap and affixed an adapter to slide the garden hose and vacuum line to.
3) Put the wick in the garden hose (which was inside the antifreeze bottle where the water was)
4) Connected the vacuum line at the top (outside of bottle- top of cap)
5) Ran the vacuum line to the needle valve, then vacuum line out of the needle valve to one of the vacuum ports on the carburetor (could run it to a vacuum port in a throttle body too, or use a T where a line goes to operate something else)

Setup> Run the engine and get it warmed up. Start opening the needle valve until the engine starts to stumble, then back it off until it runs right. I remember our gas mileage went up a few mpgs and power was better. We used this simple setup for about 2 years. About every couple months wed "reset" the needle valve when we noticed water consumption was starting to drop (due to buildup in the needle valve). That thing used a lot of water! We didnt even filter it!! I used to laugh when hed come pick me up at school- 75 in southern california middle of the afternoon and here comes the El Camino with steam coming out the exhaust. I would imagine it might be pretty hard on exhaust systems, so keep that in mind..

Maybe you could incorporate some parts of the above into your plan? I will be following your thread :)

**EDIT** Not sure if a fuel injected vehicle would stumble the same way. I imagine the computer might start leaning the fuel trims as it took on water, but im not sure. I might actually cook up Dad's old water induction and put it on my Ranger. I have an UltraGuage so I could monitor fuel trims to see..

Slime can grow in the water tank after a while.
That is what occasionally causes the clogs appear to happen for no apparent reason.
Use a little bit of methanol to kill it.
Filtering is always a good idea, as you said.

2x

Interesting idea.

reminds me of one i got from a neighbor in the 80's. it was built commercially but was old when he gave me it. the jar was very large and was hard finding a place to put it. was too young to care about measuring mileage but remembering him say it did and that was the reason i tried it.
this is a homemade unit and the operation is the same:
Rambo1965's Water Injection Thread - JeepForum.com
pics in case the link gets broken:
http://i110.photobucket.com/albums/n...psztlu8nqq.jpg
http://i110.photobucket.com/albums/n...pstrfroup6.jpg
http://i110.photobucket.com/albums/n...psjgptfj2s.jpg
http://i110.photobucket.com/albums/n...psuailepti.jpg
http://i110.photobucket.com/albums/n...psyx1ffhl9.jpg

The 6V pump worked with a diode on it so it would not get the inductive kickback from the injector. It seemed to pump about the right amount of water. But I had one major problem with this setup. It somehow made the car run very rich. I am thinking the motor being in parallel with the injector kept the injector open longer than usual. Either that or it confused the computer somehow. I am not sure what was causing it but using the water I was only able to get about 53MPG even if I wasn't actually pumping water. For this car that is absolutely terrible for summer driving. After unhooking the motor the mileage went back over 60 so it was doing something wrong.

I need to build a small transistor circuit to feed the injector signal to the motor without actually loading the injector circuit. A quick look around the web found this: https://web.archive.org/web/20120320...g/diy_aid.html It looks like it would be a pretty simple thing to build. I will probably build it and try again.

I think the setup has promise and will work once I get the details figured out. I just have to get time to build that circuit and try again. But I do like the setup described by KingZiptie so I might also try that if I can find all the parts laying around for it.

Water injection typically lowers fuel milage in gasoline motors unless its setup exactly perfect.

water injection actually helps the mileage on a gasoline engine. I have never tried it on a diesel. But I have tested and have repeatedly been able to get about a 5% increase in mileage with a ratio of 10% water to gas. You can go way over that ratio and it won't change much other than dump water out the tail pipe. On some tests in the past I have gotten close to a 50-50 mix on a warm engine when I messed up the regulator setup but the car ran fine and didn't do anything other than use up the bottle of water way quicker than it should have. I haven't seen an increase in mileage going beyond the 10% mix so that seems to be the sweet spot.

The trick is just to get a reliable method that is easy to duplicate and install on most cars without having to go to something like a megasquirt computer or some other extreme stuff.

6 pounds per hour would not be a bad starting point.
When I reinstall my water injection on my diesel I want to use well under a gallon per hour.

I already did that. Proven to last, can inject as little or as much water as you want, uses very little power.
Details are on the water injection wiki.
Gas, diesel, cars trucks and you can buy almost all the parts off ebay and tractor supply.

Maybe im being a bit pedantic, but I would at least get the input air for this setup through a filter of some kind. I would do this both to prevent clogging the metering valve as well as to prevent any chance of dirt making it into the engine. This is especially the case in dry dusty areas. The rest of the system is pretty unique- I like it!

My dad's system approached inducting water a different way. While yours seems to aim to have air and water mixed, my dad's setup aimed to output only water. The wick would soak up the water, and the vacuum would cause water to be pulled off the wick only so much as the needle valve would allow flow. The weakness of his setup would be needing to reset the needle valve every so often, or cleaning it once in awhile. Your setup doesnt have that issue as the metering valve controls air into the system instead of water out of the system.

I have read that excess levels of water can be hard on catalytic converters, though im not sure exactly how. I know water is one byproduct of converting hydrocarbons, so this doesnt make much sense to me.

Awesome thread, thanks for all the info.

I also desire to do this on a modern TDI engine. I am able to read much of the data from the OBD2 port or by connecting to the canbus of the engine. And I can use a gasoline pump and gasoline injector to output the exact amount of water.

How much of a gain in MPG can be expected using this? (the newer cars have electric water pumps so in the worst case it should lower the load on that).

Also how can one stop the corrosion of the fuel pump and the injector. (or is it even an issue with EV14 injectors) I have been reading this for the past week, and some people add some kind of oil to stop corrosion (no idea what it is).

Anyone I have seen doing this uses an agriculture spray pump and some sort of water mist spray nozzle.
None I have seen use gasoline fuel system parts.
I'm sure that there are people who do use gasoline fuel injection parts but I don't think it lasts very long.

Just read that the new gasoline engines are supposedly compatible with E85, which has corrosive water and alcohol inside. So I am pondering why not.

What water soluble oil/lubricant would not upset a diesel engine?

So, what kind of mpg gain on turbo diesels can be expected?

No and yes. Fuel pumps do not like water, but I've had good luck with a surflo style pump and a Ev-14 injector. Needs a soak in vinegar every few months but no other issues so far.
https://www.youtube.com/watch?v=IpJmNfy-zd4

Up to 6% on diesels only in warmer environments.

Is there andvantage in traffic situations or just cruising/accelerating? I suppose cooling the engine once in a while looking at the exhaust temp could relieve some load from the engine cooling system.

I don't know anyone that tried it in stop and go. I don't think it's a good idea to use water injection at idle.

I bought a water-injection kit from JC Whitney 30 years ago. I installed it on a '76 Ford 500 with a 351 CID V-8 that I used to tow a travel trailer. I got the kit because I really worked that Ford towing up the mountains, and I was doing everything I could to prevent preignition knock when under heavy load using regular unleaded.

The water injector had a vacuum switch that activated a small pump to inject water into the carburetor when the vacuum got low, about 4 inches of mercury as I recall. I wired a light to tell me when the pump was activated.

It worked, although I cannot say how effective it really was. I certainly did not notice any increase in fuel mileage. But I got my $50 worth of entertainment out of it, which was what it cost.

I think it was built by Spearco.

That's pretty much exactly what I am going to try and do with my big block Chevy build. It's got 11:1 compression and I'm going to try and run it with regular gas and water methanol for higher load situations.

4"Hg, I will try to remember that.

Most of the fuel injection hardware nowadays are compatible to E85, and the ethanol is actually more corrosive than water. Anyway, since in my country we use hydrated ethanol at a concentration of 96% by volume with the other 4% being mostly water, and that an ethanol-capable engine can still operate at a concentration of 80% ethanol by volume with the other 20% being water (seems inviting to run on homebrewed vodka not standardized to 40% alcoholic volume), it sounds like using hardware from a fuel system for the water spraying device won't get you in trouble as long as you avoid using tap water. Distilled water prevents electrolythic corrosion of the metal parts.


Alcohols, either ethanol or methanol, can be used to emulsify some lube oils and the water. Those castor-based oils used for competition 2-stroke engines are more likely to work since they're easily soluble on alcohols.