In this study computational fluid dynamics (CFD) was used to model fluid flow and diesel combustion in an IC engine that uses a pre-chamber and a main-chamber. The pre-chamber is located in the cylinder head and a bowl in the piston serves as the main chamber. The study considers the effect of diesel combustion in the pre-chamber on turbulence generation and hence fuel-air mixing and combustion in the piston-bowl. Diesel fuel was injected directly into the pre-chamber and the piston bowl at different times. In order to better determine the effect of pre-chamber combustion on the main chamber combustion, various pre-chamber injection timings were considered. The results show that pre-chamber combustion caused the average cylinder pressure to increase by up to 20% in some cases.