Water Induction to Save Fuel - DECOMMISSIONED
Intro: Water Induction to Save Fuel - DECOMMISSIONED
Driving in rain or to work on early mornings I had noticed my fuel economy improved by a small amount. Could it be the higher water vapour content in the air? Via research I came across an old technique called water injection used in the world War 2 era. Basically a fine mist water is introduced into the air intake manifold and this is burnt in the combustion Chambers.
The water mist is converted to steam which increases the compression ratio of the engine. The steam also cleans the built up carbon in the cylinders and also the oxygen sensor.
One month after implementing my own blend of water injection (water induction), I gained an extra 40km on a full tank of gas! The original stock range on my lev civic was a pitiful 290km. Four years after implementation of water injection, I typically get 460km. On consecutive long drives I will get over 560km per tank.
This project works reasonably well on cars without a catalytic converter. I have tried this on a car with its cat still installed and the project was a failure. Also, the needle valve used to control the flow of water into the intake manifold is critical in its percent open state: even a little too much water and the engine will splutter so its very important to use the smallest possible flow of water to achieve misting.
Now let me Show you what I did to obtain these results and it cost me less than 100TT dollars.
STEP 1: Vacuum Line to the Air Intake Manifold.
I used the vapour line that pulls gasoline vapours stored in a charcoal canister. Years ago the rollover valve in my gas tank got stuck in the closed position. As a result I condemned that vapour line and removed the fuel vapour recovery hardware. The vacuum line as a result was available for my use to get a controlled amount of water into the air intake manifold. In the pic that's the hose with the copper tubing link.
Please note that if you introduce water mist before the air intake throttle you will sieze up your intake air control valve (and the electronic throttle if you have that) . Water mist must be introduced downstream of these devices for a reliable solution.
STEP 2: Valve to Control the Water.
Using a brass needle valve for water control, I connected to the vacuum line. A very small amount of water is needed as even a little too much will cause the engine to cough and stall! If that happens it will need water removal from the air intake manifold and lots of heavy revving to start back.
Using a quarter inch inner diameter tubing, my flow is approximately 20mm travel of water in 15 seconds. I made a red mark to know how much to turn from the lock off position.
As water becomes mist via this valve, it gets really cold. Small scale refrigeration! This is a future project I will try to tap into.
STEP 3: Water Reservoir .
Any bottle will work. Just have the tubing inserted and that's it. My bottle there gives me a month's supply. The water required is very small and it is only sucked into the engine when the throttle is closed (strongest vacuum at that position).
Important to note is I had removed my Catalytic converter. It was over ten years old at the time and past its service life. I used this water injection technique on another car without a Catalytic converter and it got much better fuel economy. I tried on a vehicle with a converter and that vehicle experienced the opposite!
When I start my car, steam exits the exhaust and carbon residue is deposited on the inside of the tailpipe. I no longer get the typical gasoline car exhaust smell. It smells much cleaner however I don't go sniffing that tailpipe for the good vibes.
This has been one of my most successful hobbies and literally pays for itself.
STEP 4: Exhaust Debris.
As shown on the pics, Steam condenses to form a small quantity of water on the tail pipe. Carbon from inside the engine has been deposited due to the cleaning action of the steam. My Tail pipe is always cool to touch thanks to this effect.
STEP 5: Side Effect: Refrigeration
I added a small radiator and separate water bottle with needle valve to test a theory. Under the pull of vacuum line, liquid water become water vapour much easier. To become vapour it needs to absorb thermal energy. This is why the vacuum line became so cold when the car starts. I have decided to use this phenomenon to produce low level air conditioning.
The temperature difference measured was greater than 14C. The radiator got cold enough to form condensation on a hot day in Trinidad.
I will make use of the refrigeration side effect to further another project.
21 Comments
rimar2000 9 years ago
I think this should be done only when the engine has reached standard operating temperature. Otherwise, part of the energy generated by the fuel will be used heating the water and it is likely that the balance be negative.
It's interesting how you solved the problem of prevent water entering the engine when it is turned off.
Mjtrinihobby 9 years ago
atomic79greg 3 years ago
fred3655 9 years ago
atomic79greg 3 years ago
Mjtrinihobby 9 years ago
atomic79greg 3 years ago
I have a similar set up on my catalytic converter-equipped car and it has given me about a 10% gain in mileage/fuel efficiency, or an increase in my miles/dollar, and a decrease in my CO2 emissions per gallon of gasoline.
Seán Walsh 9 years ago
Very interesting.. Probably not worth doing in wetter countries like mine though :)
Mjtrinihobby 9 years ago
atomic79greg 3 years ago
I've made a bubbler-type water induction system. Engine vacuum from the PCV port is modulated by a needle valve; intake air is passed through aquarium "airstones" to make crazy amounts of bubbles and the associated water vapour in the vessel. It could be made a semi-closed loop with the liquid condensate from the AC/defog system being drawn into the vessel with engine vacuum rather than dripping away.
The real trick to mitigating the perceived vacuum leak of my system is to modify the signal from the MAP sensor correctly, (otherwise your car's computer will overdeliver fuel until the o2 sensors can trim that back) before triggering an OBD/engine code. you could also fine tune fuel delivery by modifying o2 sensor signals to the computer for very specific fuel delivery control. I've increased my fuel economy by almost 50% over gov't ratings without affecting performance. (some would consider that an almost 50% increase in performance...)
LlewellynK 4 years ago
Norfolkson 7 years ago
Computerized water injection systems are still in use today, mostly on diesel engines. Edelbrock made a similar electronic system in the 80s called Vara-jection. With one of these installed one could advance the timing on a non-computer controlled engine to get more power. The water (or alcohol) cooled the intake charge enough to prevent detonation. The downfall of these is that if you forgot to fill the water reservoir or the electronic control module died you would have to back off the timing right away or risk a holed piston.
nathantimm 8 years ago
Could it be possible to use this same concept but with added pressure, so instead of feeding controlled vapor into the intake have water heated to produce a pressurized steam/vapor type induction, making greater compression with the benefits of the vapor?
Mjtrinihobby 8 years ago
Decommissioned. No further development.
skrubol 8 years ago
Diesel's generally do not have any manifold vacuum as they run lean (and often don't have a throttle valve.) Most diesel's intake manifolds will be under pressure from the turbo.
Terra Karma 8 years ago
Wait, you REMOVED your fuel vapor vacuum line? This would cause a drop in fuel efficiency! That line recycles unburned gas!
Mjtrinihobby 8 years ago
skepticaljay 9 years ago
Mjtrinihobby 9 years ago
CaseyCase 9 years ago
Rust?