Fuel Injection Nozzle Fuel Velocity

Recently, we did an analysis of fuel velocity coming out of a mechanical fuel injection nozzle. Fuel velocity is a function of fuel pressure. Higher pressures make higher fuel velocities. We found that fuel velocities from common fuel pressure ranges were below the port air velocity in normally aspirated engines. This could explain why, in some applications, nozzle location dramatically affects horsepower. Slower fuel velocity may reduce inlet air flow. More information is in our new book about high horsepower tuning of normally aspirated racing engines.