John:

Go to a thread entitled "water injection questions from the Quincy forum". You can find it under Technical Discussion Topic on BRF, page 6, date 1/21/07. Those comments/information might be helpful to you. The original idea seems to have orginated in the 60's because of research being done to try to increase power on early jet engines on commercial aircraft for takeoff. When injecting a water/alcohol mix into the engine, in front of the compressor blades I believe, they found that the noise level was also affected greatly, namely it quietened the engine down considerably. The reason was that the water/alcohol mix cooled the incoming air and also the combustion process somewhat and that changed the wave form distance in the sound waves being emitted by the engine. As you probably know, changing the distance the sound wave travels from the reflecting point on an exhaust system also changes the power band, and from there it was a short step for people who became aware of that research to try it on exaust systems on 2 strokes, first with megaphone exaust and then on expansion chambers. This research was widely publicized at that time, and I remember calling Harry ZAK about it. This was about the same time that Christner put water injection on the Flatheads and Harry also used it on his first ZAK pipes as they did not slide and he needed a way to change the powerband, which that accomplished. I really don't know who was first and don't think it makes much difference, but that was the time frame involved, so it is not a new concept, and as a lot of other things that speed freaks pick up, came from the aviation industry.