del@dataio.UUCP (07/19/84)
< nonononono please.... leave a line for me > - > From: Dave Williams > I was also thinking of adding a water injection > system, such as a Holley or Edelbrock. I then could advance > the timing several degrees which should help gas mileage as > well as power. Has anyone out there had any experience with > these units? I would like to hear from you. I started to mail this reply, then decided it had general interest: I use water injection on my Beast. It was the only way I could run any kind of reasonable advance at all. My engine is not stock, so it may not be representative, but I found I could advance my timing by a full ten degrees with water injection! I recommend it highly. The only reason Detroit doesn't use water injection on stock cars is that the American Public is notorious for ignoring things like oil, water, and air in the *non*maintenance of their cars. After all, the manufacturer has to warrantee the car. If the water runs out on a car that has been tuned to expect it, you get totally destructive detonation. Benefits: - You reduce detonation, prolonging engine life and improving gas mileage. - In most cases you can increase the spark advance, improving efficiency and with it, gas mileage. - The water mixture continuously steam cleans the inside of your motor. It is really something to pull a set of spark plugs after 15,000 miles and have them looking like new (except for the rounded electrodes, of course). I broke a stud off and had to pull a head after ~ 40,000 miles: I was very impressed with the lack of any carbon deposits. - The engine runs cooler. - You can run alchohol in the reservoir. This results in an even cooler running engine. - If you do run alchohol, and if you rejet for the cooler, alchohol based mixture, you get an increase in power. Not recommended unless you are a hardcore performance freak. This option partially negates the steam cleaning effect mentioned above. Drawbacks: - You have to keep filling the thing! - During the winter you must add anti-freeze (usually alchohol) to keep the reservoir from freezing. - As identified above: If you let it run out of water, you stand a chance of lunching your engine. *** IMPORTANT! *** - You cannot simply mash the accelerator to the floor, it takes a finite amount of time to sense engine load and start the water flowing. - It takes a fair amount of twiddling to get the water flow curve right if your unit provides for that. If your unit does not have the capability to modify the curve, it will be wrong for you car. - You have to figure out some way to route the hose into the air cleaner and position it above the carb throat. I have seen this get very messy in some installations. Also, multiple carbs may require multiple units. To select a good unit: - It should monitor both RPM's and vacuum if you want to match it to your engine for best performance. I also saw a unit that hooked up to the throttle linkage. Don't remember the name. - You should have the ability to adjust (for each parameter monitored): 1) The activation point. 2) The rate at which flow increases for a change in that parameter. 3) The maximum flow rate. - Again, avoid units which only check vacuum, they don't work well. Erik Lindberg AKA del ...!uw-beaver!teltone!dataio!del ( I used to call myself a hacker.... )