Water Vapor Injection has actually been around for quite a while. Even these days you can purchase complete systems, but they are very pricey. The idea is simple enough. If you add Water Vapor to the intake manifold, the water vapor will lower the temperature or the fuel/air charge. Once in the combustion chamber, the water vapor will increase the pressure and even help clean out deposits, which will also increase overall performance.
I didnít feel like spending the $300 - $600 for a professional system that may or may not work. My first prototype used a couple of Planters Peanut jars and some spare vacuum tubing I had laying around. For my second prototype, I used a Medical Vacuum Canister ($10) and an aquarium valve, tubing and air stone ($5). This set up worked, but I wasnít thrilled with the low airflow, and the alcohol I was playing with deteriorated the glue I was using on the connectors and even the medical vacuum canister started coming apart. I needed something a bit more sturdy, so I went to Lowes and bought everything I needed for around $25. I bought a half gallon glass jar with a metal lid. I splurged for a brass metering valve, tees and plastic tubing used for ice maker water lines. I even sealed all holes to the jar with JB Weld for resistance to any chemicals I may choose to throw in there. The Safety Reservoir was made using PVC tubing with caps. I then fabricated some metal clamps to hold both tanks together and I suspend them from the metal rod that runs down each side of the engine compartment of my Jeep.
OK. Here is a diagram of how the Water Vapor Injection System works.
The diagram reads from Right to Left, simply because thatís how I built it in my Jeep.
The system has TWO holding tanks. The first is the Main Tank. This is where the water is stored and where the vapor is created. The second smaller tank is the Safety Reservoir.
Air enters the Vapor Injection System through a metering valve. The metering valve is important in order to adjust the amount of bubbles in the water. Too many bubbles will cause too much water to be sucked into the Safety Reservoir. Should you expect to be in rough terrain, you can also choose to close the metering valve, shutting off the Water Vapor System entirely.
After the metering valve, the air travels to the bottom of the Main Tank. I run a T at the bottom of the Main Tank with plastic tubing with holes drilled every ľ inch. This allows a healthy amount of bubbles to form.
Once the bubbles rise from the water and make some vapor, there is a hole at the top of the tank to move the vapor into the safety reservoir.
Why have a Safety Reservoir, you might ask? Well, should the water in the Main Tank rise up (which can easily happen in a hard corner or on a bumpy trail) and be sucked into the engine. That would be a bad thing. In order to prevent siphoning, the Safety Reservoir will stop siphoning from taking place and allow a place for water to be collected instead of getting to the engine.
There is also a drain in the bottom of the Safety Reservoir. Vapor does accumulate so you will need to drain it regularly.
From the Safety Reservoir, the vapor travels directly into the engine via any unused Vacuum Port beneath the CARB or TBI. Should no port be available, you can splice in to an existing vacuum line by use of a T fitting. It is absolutely critical that the vacuum port be below the CARB or TBI. If it is placed anywhere else, there will not be enough vacuum to make the system work. If there are no bubbles, the system is not working.
I did experiment with adding alcohol to the Main Tank. I used Rubbing Alcohol and Isopropyl Alcohol. I really wanted to try out some Methanol, but couldnít find any. The Alcohol did provide me a noticeable increase in performance, but definitely made some noxious exhaust. I also tended to romp down on the gas a bit more, so that nullified the MPG gains I was hoping for.
I drive a 1990 Jeep Wrangler with a 258 motor. A few years ago, I switched to the Howell Fuel Injection System and averaged 14.5 MPG. After installing the Water Vapor Injection System, my MPG rose to a low of 16.5 MPG and a high of 18.1 MPG. Iíve had it in for 8 months now and can state that it does work for me. I live in Las Vegas and had to remove the system for the annual smog check. While the system was off, my gas mileage once again dropped to 14.5 MPG and rose once I returned the system to my Jeep. Perhaps itís not scientific, but it works for me. During the winter months, I do add some alcohol to the main tank to prevent freezing. With no moving parts there really isnít anything to break. I just have to keep the water filled. During the winter months, I had to fill the tank every month or so. I figure with the blistering heat of summer, I may need to fill it more often.
I was worried that the computer controlling the Howell system might interpret the Water System as a Vacuum Leak. That has not been the case at all. So long as the water covers the bubblers, there is no vacuum leak at all. Itís pretty sweet.