Abstract : As a follow-on to previously developed engine weight estimation work, a preliminary design engine cost estimating code has been produced. The code relies on engine thermodynamic characteristics and weight as computed by earlier developed codes to select raw material types and quantities required to produce the engine. An existing Navy technique is then used to convert this data into engine cost. The code was used to predict the cost of three existing engines; errors ranged form 1 to 8% of actual costs as reported to NADC. (Author)