Spark Arrestor plays critical role in impeding the embers emission from diesel engines as it arrests and traps the embers and the sparks inside it. Spark Arrestors have a significant impact upon the acoustic performance of diesel engines. Sound Insertion loss is an important parameter for evaluating the overall sound level emitted from diesel engine generators. In this paper the effect of new designed centrifugal trapping type was acoustically modelled and experimentally verified. The acoustics design and simulations were performed using two-port theory where, the Spark Arrestor models are limited to the plane wave range. These models were implemented in SIDLAB software for simulating the propagation of low frequency sound and air flow in ducts. The Spark Arrestor model was tested on a real diesel engine generator of 38 KWm complying with Standard ISO 8528-10:1998(E). The insertion loss simulation model matched the measurement at full engine load at 1500 rpm.