here's a thought---------if the residue inside the intake is untouched the "clean" area at the rear might be due to the washing effect of the unatomized alcohol injected into the airstream----------alcohol seems like a good idea but i am not convinced that the injection method we use is very precise-------the additional mass of the liquid (in addition to its vastly different flash point) could easily cause it to pool and tend to favor the rear runners------if the alcohol is not suspended in the air it is not going to be distributed anywhere the same--------one thing is certain------if you had no injectors in the engine and relied on a nozzle like is used to inject alcohol for gasoline injection i doubt the engine would run worth a darn even if you could control the overall flow rate----------I'd be willing to make a long bet that you would be hard pressed to get anything close to even fuel distribution to all the cylinders-------i cannot picture that working at all so how can we expect for it to work for the alcohol???--------i think we need to develop a way to inject the alcohol in a manner that insures that it is atomized well so it will stay suspended in the air and be distributed in the same percentages as the air--------perhaps in extreme situations we are trying to add so much alcohol that it is not possible for it to be properly atomized no matter how we inject it-------just my thoughts.................RC