Measuring Rate of Fuel Injection in an Operating Diesel Engine

UNKNOWN factors regarding fuel-injector performance have handicapped diesel-engine combustion studies in the past. Rate at which fuel is introduced into the engine cylinder and quantity of fuel available for combustion at any instant were two basic unknowns hindering advance. This paper presents results of an investigation aimed at measuring fuel-injector performance in a firing engine, simultaneously with obtaining pressure-time curves and other needed data. Method and instrumentation developed covers three characteristics of injector performance: 1. Rate of fuel injection. 2. Fuel-injection timing. 3. Injection pressures. The method results in obtaining more comprehensive data, but has the disadvantage of added complexities requiring skilled handling.