Abstract: A computer program product including a program that causes the computer to perform operations when the computer executes the program includes instructions to provide an engine specification interface to a user over a web-based application, and to receive an application specification including a three-dimensional description of application space available to accommodate an engine and a parameter for an engine application. The instructions include accessing an engine specification in response to the parameter for the engine application, where the engine specification includes a three-dimensional digital description of an engine and specified additional hardware. The instructions include evaluating compatibility between the engine specification and the application specification, and providing a CAD file to the user, where the CAD file includes the three-dimensional digital description of an engine and specified additional hardware.