PRO..........too much work............
Quote:
Originally Posted by
Neil_M50D2
Racing alcohol ranges from about 92% to 96% fuel, the rest is water. We have adjusted the water content to adjust the lean-rich. Some water seems to be good, but too much is just wet. All it takes is very good hydrometer and some simple calculations to increase the water content up. Just remember that as the water content goes up the engine will run leaner. The rich-lean effect seems to be more important than the amount of water present.
Neil Bass
no wonder I only race stock and mod.........hydrometer, altitude, jetting, etc.........jeez...............just add gas and oil and go..........(for me)......LOL!!:D
Regarding water in the Alcohol
As soon as you open a new barrel of alcohol it absorbs moisture from the air. You may start with some real high percentage alcohol but by the end of the season it has dropped several percent. We found no real observable difference as long as the engine was jetted properly.
One race at Laurence lake Sid’s 500 was running too rich, so we hydro mitered some of our un-mixed fuel, ran some numbers then added ¼ cup water to lean the engine. Those around just looked with big eyes as I scooped ¼ cup directly from the lake to the fuel tank. It worked so well one of the competitions borrowed our hydrometer, but I do not think he new what to do with it.
Loved those days.
Neil Bass
advantage and disadvantage of water injection in pipes
As Sam has mentioned in his earlier post the injection of water into the exhaust system cools the exaust gas and makes the engine think the pipe is longer than it really is while the water is being injected, giving you more bottom end/torque allowing you to pull a larger prop through the tough part of the power band, which is just when the boat breaks over on plane and puts a load on the engine. Larger prop at peak rpm equals more speed. I set a Kilo record in the mid 80'd at almost 91 MPH with a Yamato Model 80 on fuel with ONE 25mm CARB, using water injection as an aid to keep going after breaking over on plane and continue on with a larger than usual prop, thus achieving a speed that would not normally have been possible.
We used a ordinary aftermarket winshield washer system purchased at an auto supply store consisting of a plastic container that held about a quart of water and had a 12 volt motor mounted in the bottom of the container. Real neat and tidy and easy to mount. Ran two hoses, one to each collector pipe for each expansion chamber with a capability of inserting bing carb jets in the stand off pipe brazed in the collector so as to adjust the amount of water injected when you pushed the button. Used a small 12V battery from a portable VCR that weighed about a pound so very small and lightweight for power.
The Disadvantage: you needed a very good check valve in the line or two was better for safety as the motor would have a tendency at high RPM to suck water from the tank whether the switch was activated or not because of suction developed by the expansion chambers. In addition to slowing the motor down if this got into the pipe at the wrong time, you could actually suck the water vapor into the cylinders where it turned to steam immediately and the additional pressure of the steam plus normal combustion would crack pistons like walnuts. We destroyed several pistons before Harry ZAK finally figured out what was happening and got some decent check valves in the line to stop the problem.
Another disadvantage was that if you had it hooked up all the time, the tendency was to use it too often, sometimes mistaking a non-connected engine problem with loading the engine by thinking you had a little too large a prop on and trying to get the motor going when that was not the problem at all.
Short and sweet, for the right reasons it was good to have but easy to overuse if you weren't careful, and could be hard on the engine as mentioned.