[rotrex]

The 'quickly' is the issue. Taking the bends generates enormous g-forces throwing the droplets against the runner wall. While the methanol will still evaporate passing the valves and within the chamber, the water will do much less so as a stream of water running along the runner's floor. This is a other reason the fuel injectors are close to the intake port in the straight section. They point right at the valves in the direction of the air flow. This minimizes fluid separation.