Teams have an option of building their own engines or they may run a specification engine, similar to what is used in many short tracks. Both engines are V8, pushrod, 12:1 compression motors. "Built" motors are built to team specifications using any configuration of pieces as long as it still meets NASCAR specifications. The spec engine is built using NASCAR-Approved pieces that may be purchased from an approved supplier. The engines may be purchased as a kit or pre-assembled. All of the spec pieces are individually encrypted with a barcode for verification and tracking purposes and can be checked during the inspection process with an encryption reader.