I just installed a hi tech alcohol-water injector on the modified GMC 302 in my 37 Chevy pu.The engine was detonating at full throttle on 93 octane,not the light pinging ya get when pulling a hill at part throttle,but the detonation that turns pistons inside out.The engine has a heated intake for good low speed performance,but the heated intake,agressive spark advance and 9.5-1 actual compression causes detonation at full throttle.Unheat the intake,gas mileage and low speed running is poor.Reducing the total timing helps,but also cuts performance.
The water-alcohol injection solved the problem without performance reducing retuning,and I can run 91 octane instead of 93 if necessary.It cools the mixture and the alcohol adds a slightly higher octance rating.Common windshield washer fluid works dandy,a gallon lasts a tank of gas for reasonable normal driving.
Water-alcohol injection or anti detonation fluid was used extensively by Allison on their V-12 aircraft engines during WW2.GM also used a water -alcohol injection on the early 60's turbo charged Olds 215 V-8 engine.
This add on injection is no different than any other means used to increase performance.Of course the system needs to be properly engineered to work properly,there's more to it than just dumping windshield washer fluid into the manifold.
